www.elsolucionario.net www.elsolucionario.net www.elsolucionario.net Chemistry KENNETH W WHITTEN University of Georgia, Athens RAYMOND E DAVIS University of Texas at Austin M LARRY PECK Texas A&M University GEORGE G STANLEY Louisiana State University Australia • Brazil • Japan • Korea • Mexico • Singapore • Spain • United Kingdom • United States www.elsolucionario.net Ninth Edition www.elsolucionario.net Publisher: Mary Finch Sr Acquisitions Editor: Lisa Lockwood Development Editor: Teri Hyde Assistant Editor: Ashley Summers Editorial Assistant: Elizabeth Woods Sr Media Editor: Lisa Weber Sr Marketing Manager: Nicole Hamm Marketing Coordinator: Kevin Carroll Marketing Communications Manager: Linda Yip Project Manager, Editorial Production: Teresa L Trego Creative Director: Rob Hugel © 2010 Brooks/Cole, Cengage Learning ALL RIGHTS RESERVED No part of this work covered by the copyright herein may be reproduced, transmitted, stored, or used in any form or by any means, graphic, 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Canada 12 11 10 09 www.elsolucionario.net Chemistry, Ninth Edition Kenneth W Whitten, Raymond E Davis, M Larry Peck, George G Stanley This edition of Chemistry is gratefully dedicated to Professor Emeritus Kenneth W Whitten and the late Professor Kenneth D Gailey, whose pedagogic insights and clarity of organization provided guidance for generations of students and laid the foundation for the many successful editions of this book RED, MLP, and GGS www.elsolucionario.net www.elsolucionario.net www.elsolucionario.net www.elsolucionario.net This page intentionally left blank www.elsolucionario.net Brief Contents The Foundations of Chemistry Chemical Formulas and Composition Stoichiometry 48 www.elsolucionario.net 10 11 12 13 14 15 16 17 18 19 20 Chemical Equations and Reaction Stoichiometry 86 The Structure of Atoms 119 Chemical Periodicity 177 Some Types of Chemical Reactions 211 Chemical Bonding 250 Molecular Structure and Covalent Bonding Theories 287 Molecular Orbitals in Chemical Bonding 329 Reactions in Aqueous Solutions I: Acids, Bases, and Salts 347 Reactions in Aqueous Solutions II: Calculations 374 Gases and the Kinetic-Molecular Theory 400 Liquids and Solids 448 Solutions 502 Chemical Thermodynamics 548 Chemical Kinetics 606 Chemical Equilibrium 660 Ionic Equilibria I: Acids and Bases 703 Ionic Equilibria II: Buffers and Titration Curves 743 Ionic Equilibria III: The Solubility Product Principle 771 v www.elsolucionario.net Brief Contents 21 22 23 24 25 26 27 28 Electrochemistry 794 Metals I: Metallurgy 841 Metals II: Properties and Reactions 859 Some Nonmetals and Metalloids 879 Coordination Compounds Nuclear Chemistry 907 934 Organic Chemistry I: Formulas, Names, and Properties 970 Organic Chemistry II: Shapes, Selected Reactions, and Biopolymers 1035 APPENDIX A | Some Mathematical Operations A-1 APPENDIX B | Electronic Configurations of the Atoms of the Elements A-5 APPENDIX C | Common Units, Equivalences, and Conversation Factors A-8 APPENDIX D | Physical Constants A-11 APPENDIX E | Some Physical Constants for a Few Common Substances A-12 APPENDIX F | Ionization Constants for Weak Acids at 25°C A-14 APPENDIX G | Ionization Constants for Weak Bases at 25°C A-16 APPENDIX H | Solubility Product Constants for Some Inorganic Compounds at 25°C A-17 APPENDIX I | Dissociation Constants for Some Complex Ions A-19 APPENDIX J | Standard Reduction Potentials in Aqueous Solution at 25 °C A-20 APPENDIX K | Selected Thermodynamic Values at 298.15 K A-23 APPENDIX L | Answers to Selected Even-Numbered Numerical Exercises Index of Equations Glossary/Index I-1 E-1 A-26 www.elsolucionario.net vi www.elsolucionario.net Contents To the Instructor xix 2-4 Atomic Weights 2-5 The Mole 56 CHEMISTRY IN USE | Avogadro’s Number 60 To the Student xxxi 1-1 1-2 1-3 1-4 1-5 1-6 The Foundations of Chemistry Matter and Energy Chemistry—A Molecular View of Matter States of Matter Chemical and Physical Properties 10 Chemical and Physical Changes 11 Mixtures, Substances, Compounds, and Elements 13 CHEMISTRY IN USE | The Development of Science 15 1-7 1-8 1-9 1-10 1-11 1-12 1-13 1-14 Measurements in Chemistry 19 Units of Measurement 20 Use of Numbers 22 The Unit Factor Method (Dimensional Analysis) 27 Percentage 31 Density and Specific Gravity 31 Heat and Temperature 34 Heat Transfer and the Measurement of Heat 36 Key Terms 40 Exercises 40 Chemical Formulas and Composition Stoichiometry 48 2-1 Chemical Formulas 49 2-2 Ions and Ionic Compounds 53 2-3 Names and Formulas of Some Ionic Compounds 54 56 2-6 Formula Weights, Molecular Weights, and Moles 61 2-7 Percent Composition and Formulas of Compounds 64 2-8 Derivation of Formulas from Elemental Composition 65 CHEMISTRY IN USE | Names of the Elements 67 2-9 Determination of Molecular Formulas 71 2-10 Some Other Interpretations of Chemical Formulas 73 2-11 Purity of Samples 77 Key Terms 78 Exercises 79 Chemical Equations and Reaction Stoichiometry 86 3-1 Chemical Equations 87 3-2 Calculations Based on Chemical Equations 92 3-3 The Limiting Reactant (Reagent) Concept 96 3-4 Percent Yields from Chemical Reactions 99 3-5 Sequential Reactions 100 3-6 Concentrations of Solutions 101 3-7 Dilution of Solutions 106 3-8 Using Solutions in Chemical Reactions 107 Key Terms 110 Exercises 110 vii www.elsolucionario.net About the Authors xvii www.elsolucionario.net Contents 5-5 Ionic Radii 188 5-6 Electronegativity 190 5-7 Oxidation States 192 The Structure of Atoms 119 Subatomic Particles 120 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 Fundamental Particles 120 The Discovery of Electrons 121 Canal Rays and Protons 123 Rutherford and the Nuclear Atom 123 Atomic Number 125 Neutrons 126 Mass Number and Isotopes 127 Mass Spectrometry and Isotopic Abundance 128 Chemical Reactions and Periodicity Key Terms 206 Exercises 206 CHEMISTRY IN USE | Stable Isotope Ratio Analysis 130 Naming Some Inorganic Compounds 220 The Electronic Structures of Atoms 138 4-11 Electromagnetic Radiation 138 4-12 The Photoelectric Effect 142 4-13 Atomic Spectra and the Bohr Atom 143 Enrichment | The Bohr Theory and the Balmer-Rydberg Equation 146 4-14 The Wave Nature of the Electron 148 4-15 The Quantum Mechanical Picture of the Atom 150 Quantum Numbers 151 Atomic Orbitals 152 Electron Configurations 157 The Periodic Table and Electron Configurations 163 4-20 Paramagnetism and Diamagnetism 6-3 Naming Binary Compounds 220 6-4 Naming Ternary Acids and Their Salts 222 Classifying Chemical Reactions 225 6-5 Oxidation-Reduction Reactions: Introduction 225 6-6 Combination Reactions 228 6-7 Decomposition Reactions 229 6-8 Displacement Reactions 230 CHEMISTRY IN USE | Troublesome Displacement Reactions 233 151 4-16 4-17 4-18 4-19 6-9 Metathesis Reactions 235 6-10 Gas-Formation Reactions 240 6-11 Summary of Reaction Types 241 Key Terms 243 Exercises 244 166 Key Terms 167 Exercises 168 Some Types of Chemical Reactions 211 6-1 Aqueous Solutions: An Introduction 212 6-2 Reactions in Aqueous Solutions 218 4-9 The Atomic Weight Scale and Atomic Weights 131 4-10 The Periodic Table: Metals, Nonmetals, and Metalloids 133 Enrichment | The Schrödinger Equation 194 5-8 Hydrogen and the Hydrides 194 5-9 Oxygen and the Oxides 198 Chemical Bonding 250 7-1 Lewis Dot Formulas of Atoms 251 Ionic Bonding 252 Chemical Periodicity 177 7-2 Formation of Ionic Compounds 252 5-1 More About the Periodic Table 178 CHEMISTRY IN USE | The Periodic Table 179 CHEMISTRY IN USE | The Discovery of Phosphorus 180 Periodic Properties of the Elements 181 5-2 Atomic Radii 181 5-3 Ionization Energy 184 5-4 Electron Affinity 186 Enrichment | Introduction to Energy Relationships in Ionic Bonding 257 Covalent Bonding 259 7-3 Formation of Covalent Bonds 259 7-4 Bond Lengths and Bond Energies 260 7-5 Lewis Formulas for Molecules and Polyatomic Ions 261 7-6 Writing Lewis Formulas: The Octet Rule 262 www.elsolucionario.net viii www.elsolucionario.net GLOSSARY/INDEX constant (also known as the Law of Conservation of Energy); energy is neither created nor destroyed in ordinary chemical reactions and physical changes, 550–551, 551i, 595 First order reaction, 622–624, 627 Flotation A method by which hydrophobic (water-repelling) particles of an ore are separated from hydrophilic (waterattracting) particles in a metallurgical pretreatment process, 844, 855 Fluids Substances that flow freely; gases and liquids, 401, 438 Fluorescence Absorption of high-energy radiation by a substance and the subsequent emission of visible light, 944, 964 Fluorine, 883–884 heteronuclear diatomic molecules and, 339–340 homonuclear diatomic molecules and, 338 Flux A substance added to react with or dissolve the charge, or a product of its reduction, in metallurgy; usually added to lower a melting point, 855 Foam A colloidal dispersion of a gas in a liquid, 541 Fomula unit equation An equation for a chemical reaction in which all formulas are written as complete formulas, 243 f orbitals Beginning in the fourth shell, a set of seven degenerate orbitals per shell, higher in energy than s, p, and d orbitals in the same shell, 167 periodic table and, 165i quantum numbers and, 152, 156i Force of attraction ion–ion interactions and, 451–452 Formal charge The hypothetical charge on an atom in a covalently bonded molecule or ion; bonding electrons are counted as though they were shared equally between the two bonded atoms, 268–270, 280 Formaldehyde, 1001t Formic acid, 1005t Formula Combination of element symbols that indicates the chemical composition of a substance, 78 for ionic compounds, 55–56 Formula unit The smallest repeating unit of a substance—for non-ionic substances, the molecule, 53, 78, 218, 254–255 Formula unit equation A chemical equation in which all compounds are represented by complete formulas, 367, 387 Formula weight The mass, in atomic mass units, of one formula unit of a substance Numerically equal to the mass, in grams, of one mole of the substance (see Molar mass) This number is obtained by adding the atomic weights of the atoms specified in the formula, 61–62, 78 Fossil fuels, 204–205 Fractional distillation The process in which a fractionating column is used in a distillation apparatus to separate components of a liquid mixture that have different boiling points, 541 colligative properties (of solutions) and, 520–522, 521i Fractional precipitation Removal of some ions from solution by precipitation while leaving other ions, with similar properties, in solution, 781–784, 789 Frasch process A method by which elemental sulfur is mined or extracted Sulfur is melted with superheated water (at 1708C under high pressure) and forced to the surface of the earth as a slurry, 889, 889i, 902 Free energy change, 588–591 Freezing point, 525–526 See Melting point Freezing point depression The decrease in the freezing point of a solvent caused by the presence of a solute, 523–525, 541 Freezing point depression constant Kf , 523–525 constant that corresponds to the change in freezing point produced by a onemolal ideal solution of a nonvolatile nonelectrolyte, 541 Frequency (n) The number of crests of a wave that pass a given point per unit time, 138–142, 139i, 167 f-Transition elements (metals) Elements 58 through 71 and 90 through 103; also called inner transition elements (metals), 180–181, 206 Fuel cell A voltaic cell in which the reactants (usually gases) are supplied continuously and products are removed continuously, 833 Functional group A group of atoms that represents a potential reaction site in an organic compound, 973, 993, 1025 addition reactions and, 1017 alcohols/phenols and, 996–999, 996i, 997i, 999t aldehydes/ketones and, 1000–1002, 1001i, 1001t amines and, 1002–1004, 1003t carboxylic acid and, 1004–1008, 1005i, 1005t, 1008t ethers and, 999–1000 heteroatoms and, 994 isomers, 1037 organic halides and, 994–996, 995t summary of, 1013i Fundamental particles Subatomic particles of which all matter is composed; protons, electrons, and neutrons are fundamental particles, 6, 120–121, 121t, 167 Fundamental step See Elementary step Gallium as Group 3A metal, 869t, 870–871 Galvani, Luigi, 803 Galvanic cell See Voltaic cell Gamma ray (g) High-energy electromagnetic radiation, 940–941, 941i, 947, 964 food irradiation and, 952–953 nuclear waste and, 962 Gangue Sand, rock, and other impurities surrounding the mineral of interest in an ore, 842, 855 Gaseous state of matter, 9–10, 10i Avogadro’s Law/standard molar volume and, 413–414 characteristics of, 450t compared with liquids/solids, 401–402, 401t and composition of atmosphere/gas properties, 402 Boyle’s Law and, 406–409 Charles’s Law and, 409–411 Combined Gas Law equation and, 412–413 Dalton’s Law of Partial Pressures and, 420–426 diffusion/effusion and, 433–435 diffusion/effusion of, 433–435, 434i greenhouse effect and, 404–405 ideal gas equation and, 414–418 kinetic–molecular theory and, 428–433 and mass–volume relationships in reaction, 426–428 and molecular weight/formula determination, 418–420 nonideal gas behavior and, 435–438 pressure and, 403–406 solid/liquid/gas comparisons, 401–402 standard temperature and pressure (STP) and, 411 Law of Partial Pressures and, 420–426 Gas-formation reaction A reaction in which an insoluble or slightly soluble gas is formed as a product, 240–241, 243 summary/characteristics of, 242t Gas ionization counters, 945, 945i Gay-Lussac, Joseph, 409 Gay-Lussac’s Law of Combining Volumes At constant temperature and pressure, the volumes of reacting gases (and any gaseous products) can be expressed as ratios of small whole numbers, 438 mass/volume relationships and, 427–428 Geckos and dispersion forces, 456 Geiger–Müller counter A type of gas ionization counter used to detect radiation, 945, 945i, 964 Gel, A colloidal dispersion of a solid in a liquid; a semirigid sol, 537, 541 Generator, 831 Geometric isomerism Compounds with different arrangements of groups on the opposite sides of a bond with restricted rotation, such as a double bond; for example, cis–trans isomers of certain alkenes, 919–921, 920i, 928, 982, 1025, 1037–1038, 1064 Germanium, 135t Germer, L H., 148–149 Gibbs free energy, G The thermodynamic state function of a system that indicates the amount of energy available for the system to useful work at constant T and P It is defined as G H TS; also called free energy, 588–591, 595 Gibbs free energy change, ∆G The indicator of spontaneity of a process at constant T and P ∆G ∆H T∆S If ∆G is negative, the process is product-favored (spontaneous); also called free energy change, 588–591, 595 Glass electrode An electrode consisting of an AgCl-coated silver wire in contact with an HCl solution of known standard concentration (usually 1.00 M ) in a thin-walled glass bulb; when immersed in a solution, this electrode develops a potential that is sensitive to the relative www.elsolucionario.net I-10 www.elsolucionario.net GLOSSARY/INDEX Haber, Fritz, 679 Haber process An industrial process for the catalyzed production of ammonia from N2 and H2 at high temperature and pressure; see Section 17-7, 679–681, 680i, 681t, 902 Half-cell The compartment in a voltaic cell in which the oxidation or reduction halfreaction occurs, 833 Half-life of a radionuclide The time required for half of a given sample to undergo radioactive decay, 946–947, 947i, 964 See also Nuclear chemistry Half-life of a reactant The time required for half of that reactant to be converted into product(s), 622, 651 Half-reaction Either the oxidation part or the reduction part of a redox reaction, 386, 392, 814–816, 815t Halides Binary compounds of the halogens with less electronegative elements, 882, 902 in summary of functional groups, 1013i Hall–Héroult process A process in which a molten mixture of Al2O3, NaF, and AlF3 is electrolyzed to obtain pure aluminum, 850, 850i, 855 Halogenation reaction A substitution reaction in which a hydrogen atom is replaced by a halogen atom, 1014, 1025 Halogens Group 7A elements; F, Cl, Br, I, and At The free elements exist as diatomic molecules, 137, 167, 243, 902 See also Nonmetals displacement reactions and, 234 hydrogen halides/hydrohalic acids, 885–887, 886i occurrence/use/production of, 883–884 oxoacids (ternary acids) of, 887, 887t periodic table and, 134i properties of, 882–883, 882t reactions of free halogens, 884–885 Hard water Water containing Fe31, Ca21, or Mg 21 ions, which form precipitates with soaps, 538–539, 541 Heat A form of energy that flows between two samples of matter because of their difference in temperature, 40 matter and, 34–36 Heat capacity The amount of heat required to raise the temperature of a body one degree Celsius, 37, 40 Heat changes See Thermochemistry Heat of combustion The amount of energy liberated per mole of substance burned, 1064 Heat of condensation The amount of heat that must be removed from a specific amount of a vapor at its condensation point to condense the vapor with no change in temperature; usually expressed in J/g or kJ/mol; in the latter case it is called the molar heat of condensation, 464, 493 Heat of formation The enthalpy change for a reaction is the same whether it occurs in one step or a series of steps See Standard molar enthalpy of formation, ∆H 0f (of a substance) Heat of fusion The amount of heat required to melt a specific amount of a solid at its melting point with no change in temperature; usually expressed in J/g or kJ/mol; in the latter case it is called the molar heat of fusion, 468–470, 493 Heat of hydration, 505 See Hydration energy (molar) of an ion Heat of solidification The amount of heat that must be removed from a specific amount of a liquid at its freezing point to freeze it with no change in temperature; usually expressed in J/g or kJ/mol; in the latter case it is called the molar heat of solidification, 469, 493 Heat of solution (molar) The amount of heat absorbed in the formation of a solution that contains one mole of solute; the value is positive if heat is absorbed (endothermic) and negative if heat is released (exothermic), 504, 541 Heat of vaporization The amount of heat required to vaporize a specific amount of a liquid at its boiling point with no change in temperature; usually expressed in J/g or kJ/mol; in the latter case it is called the molar heat of vaporization, 467t, 493, A12 Heat transfer liquid state of matter and, 463–467, 464t matter and, 36–39 solid state of matter and, 468–470, 469t Heavy water Water containing deuterium, a heavy isotope of hydrogen, 21H, 959, 964 Heisenberg, Werner, 150 Heisenberg Uncertainty Principle It is impossible to determine accurately both the momentum and position of an electron simultaneously, 150, 167 Helium, 124–125, 881t homonuclear diatomic molecules and, 336 Helix nebula, 148 Hemodialysis, 534–535 Henderson–Hasselbalch equation An equation that enables us to calculate the pH or pOH of a buffer solution directly, For acid–salt buffer pH pK a log For base–salt buffer pOH pK b log conjbase acid conjbase base , 747–748, 750–751, 766 Henry’s Law The concentration or solubility of a gas in a liquid at any given temperature is directly proportional to the partial pressure of the gas over the solution, 513–514, 513i, 541 Hess, G H., 561 Hess’s Law, 561–565, 564i bond energies and, 566 Heteroatom An atom other than C or H in an organic molecule; the most common heteroatoms are O, N, S, P, and the halogens, 994, 1025 Heterocyclic amine An amine in which nitrogen is part of a ring, 1004, 1025 Heterogeneous catalyst A catalyst that exists in a different phase (solid, liquid, or gas) from the reactants; the vast majority of heterogeneous catalysts are solids, 645–648, 645i, 647i, 651 Heterogenous equilibria Equilibria involving species in more than one phase, 688–689, 694 Heterogenous mixture A mixture that does not have uniform composition and properties throughout, 14i, 40 Heteronuclear Consisting of different elements, 276, 280, 338–340, 339i, 340i, 343 High oxidation state transition metal oxides, 366 High spin complex A complex in which the crystal field splitting energy is smaller than the pairing energy, so that all d orbitals are singly occupied before pairing occurs; there are the same number of unpaired d electrons on the metal atom as when the metal is uncomplexed In an octahedral high spin complex, all t2g and eg orbitals are singly occupied before any pairing occurs, 925, 928 Homogeneous catalyst A catalyst that exists in the same phase (liquid or gas) as the reactants, 643–645, 651 Homogeneous equilibria Equilibria involving only species in a single phase, that is, all gases, all liquids, or all solids, 688–689, 694 Homogenous mixture A mixture that has uniform composition and properties throughout, 14i, 40, 503 Homologous series A series of compounds in which each member differs from the next by a specific number and kind of atoms, 975, 1025 www.elsolucionario.net [H1] concentrations (and hence to pH differences) of the internal standard solution and the outside solution, 833 Glucose, 506 Glyceride A triester of glycerol, 1010, 1025 Glycogen, 1055–1056 Glycols, 998, 1022 Glycosidic bond A bond linking monomers in a polysaccharide, 1055, 1064 Gold metallurgy of, 855 Graham, Thomas, 402 Greenhouse effect and climate change, 404–405 Ground state The lowest energy state or most stable state of an atom, molecule, or ion, 167 Group (family) The elements in a vertical column of the periodic table, 136, 163–164, 164i, 167, 243 Group 5A nitrogen, 893–900, 893t–894t, 900i phosphorus, 900–901 silicon, 901–902 Group 6A hydrides of, 890 oxides of, 890–892 reactions of elements of, 890 Group 6A, Selenium, 889 Group 6A, Sulfur, 888–889, 888t, 889i Group 6A, Tellurium, 889 Group 7A See Halogens Group 8A See Noble (rare) gases Guanine, 1062–1063, 1063i I-11 www.elsolucionario.net GLOSSARY/INDEX Homonuclear Consisting of only one element, 276, 280, 333, 334i, 335–338, 337t, 343 Hund’s Rule Each orbital of a given subshell is occupied by a single electron before pairing begins See Aufbau Principle, 160, 167, 333, 336 Hybridization The mixing of a set of atomic orbitals on an atom to form a new set of hybrid orbitals with the same total electron capacity and with properties and energies intermediate between those of the original unhybridized orbitals, 321t, 322 Hybrid orbitals Orbitals formed on an atom by the process of hybridization, 288, 322 molecular shapes/bonding and, 294–295 sp hybrid orbitals, 296–297, 316–317t sp2 hybrid orbitals, 297–299, 318i, 316–317t sp3d hybrid orbitals, 312, 316–317t sp3 hybrid orbitals, 302–308, 316–317t sp3d2 hybrid orbitals, 314–315, 316–317t when not applicable, 308 Hydrate A crystalline sample that contains water, H2O, and another compound in a fixed mole ratio Examples include CuSO4 ? 5H2O and (COOH) ? 2H2O, 78 Hydrate isomers Isomers of crystalline complexes that differ in terms of the presence of water inside or outside the coordination sphere, 917, 928 Hydration The interaction (surrounding) of solute particles with water molecules, 505, 541 Hydration energy (molar) of an ion The energy change accompanying the hydration of a mole of gaseous ions, 505–506, 507t, 541 Hydration reaction A reaction in which the elements of water, H and OH, add across a double or triple bond, 1018–1019, 1025 Hydride A binary compound of hydrogen, 206, 367, 890 periodicity and, 194–197, 195i Hydrocarbons A compound that contains only carbon and hydrogen, 204, 1025 classification of, 973, 973i, 995i Hydrogen compounds of nitrogen, 895–896 displacement reactions and, 231–232 homonuclear diatomic molecules and, 335–336 periodicity and, 194–197, 195i redox equation balancing and, 387–389 ternary acids and, 222–223 Hydrogenation The reaction in which hydrogen adds across a double or triple bond, 1018, 1018i, 1025 Hydrogen bond A fairly strong dipole–dipole interaction (but still considerably weaker than covalent or ionic bonds) between molecules containing hydrogen directly bonded to a small, highly electronegative atom, such as N, O, or F, 451, 453–454, 454i, 493 and dissolution of liquids in liquids (miscibility), 508i Hydrogen-oxygen fuel cell A fuel cell in which hydrogen is the fuel (reducing agent) and oxygen is the oxidizing agent, 831–832, 832i, 833 Hydrolysis The reaction of a substance with water, 726, 736 of esters, 1051–1052 ionic equilibria and, 729–730, 735–736, 736t solubility product principle and, 779 and summary of acid–base calculations, 765t Hydrolysis constant An equilibrium constant for a hydrolysis reaction, 736 Hydronium ion H3O1, the usual representation of the hydrated hydrogen ion, 349–350, 367 aqueous solution and, 356, 357t Hydrophilic colloids Colloidal particles that attract water molecules, 536–540, 537i, 539i, 540i, 541 Hydrophoblic colloids Colloidal particles that repel water molecules, 536–540, 537i, 539i, 540i, 541 Hydroxide ion aqueous solution and, 356, 357t Hypervalent, 272 See Expanded valence shell Hypohalous acids, 887 Ideal gas A hypothetical gas that obeys exactly all postulates of the kinetic–molecular theory, 414–415, 438 deviations from, 435–438, 435i, 436i kinetic–molecular theory and, 428–433 Ideal gas equation The product of the pressure and volume of an ideal gas is directly proportional to the number of moles of the gas and the absolute temperature, 407, 415–418, 438 Ideal solution A solution that obeys Raoult’s Law exactly, 541 Indicator For acid–base titrations, an organic compound that exhibits its different colors in solutions of different acidities; a properly selected indicator is used to determine the point at which the reaction between two solutes is complete, 379, 383i, 392, 736 acid–base, 757–758, 758i, 759t methyl orange as, 108 universal, 710, 758, 758i Indicator (for acid–base reactions) An organic compound that exhibits different colors in solutions of different acidities; used to indicate the point at which reaction between an acid and a base is complete, 766 Induced radioactivity, 935 Inert electrode An electrode that does not take part in the electrochemical reaction, 833 Inert s-pair effect The tendency of the two outermost s electrons to remain nonionized or unshared in compounds; characteristic of the post-transition metals, 872, 875 Inner transition elements See f-Transition elements Inorganic chemistry, Inorganic compounds, 49 binary compounds, 220–222 ternary acids, 222–224 Insoluble base, 216 Insulator, 489 Insulator A poor conductor of electricity and heat, 493 Integrated rate equation An equation that relates the concentration of a reactant remaining to the time elapsed; has different mathematical forms for different orders of reaction, 627–630, 651 Intensive property A property that is independent of the amount of material in a sample, 11, 40 Intermolecular forces Forces between individual particles (atoms, molecules, ions) of a substance, 451, 493 Internal energy All forms of energy associated with a specific amount of a substance, 568, 595 internal energy changes, ∆E and, 568–573, 569i internal energy changes, ∆E , 568–573, 569i ∆H/∆E relationship and, 574–575 International Union of Pure and Applied Chemistry (IUPAC), 67, 163, 221, 558, 914, 975 and naming of alkenes/cycloalkenes, 984 and naming of saturated hydrocarbons, 978–982 Intramolecular forces Forces between atoms (or ions) within molecules (or formula units), 451, 493 Iodine, 884 Ion An atom or a group of atoms that carries an electrical charge, 53–54, 54t, 78, 212, 280 formation of complex, 788–789 formulas/names for common, 222t Ionic bonding The attraction of oppositely charged ions (cations and anions) in large numbers to form a solid Ions result from the transfer of one or more electrons from one atom or group of atoms to another, 251, 252–258, 280 Ionic compound A compound that is composed of cations and anions An example is sodium chloride, NaCl, 53–56, 78, 212, 251, 280 moles and, 62t solubility guidelines and, 216–217, 217t Ionic conduction Conduction of electric current by ions through a pure liquid or a solution; also called Electrolytic conduction, 833 Ionic equilibria (acids/bases) and autoionization of water, 705–706, 705t pH/pOH scales and, 707–710, 709t polyprotic acids and, 723–726 and salts of strong bases/strong acids, 727–730 and salts of strong bases/weak acids, 727 and salts of weak bases/strong acids, 730–731 and salts of weak bases/weak acids, 731–734 and salts with highly charged cations, 734–736, 736t solvolysis and, 726–727 strong electrolytes and, 704–705 weak monoprotic acids/bases and, 710–723, 710i, 711i, 711t Ionic equilibria (buffers/titration curves) acid–base indicators and, 757–758 buffering action and, 750–753 and buffer solution preparation, 753–757 www.elsolucionario.net I-12 www.elsolucionario.net common ion effect/buffer solutions and, 744–750 and strong acid/strong base titration curves, 759–762 and summary of acid–base calculations, 765t and weak acid/strong base titration curves, 762–764 and weak acid/weak base titration curves, 764 Ionic equilibria (solubility product principle) determination of Ksp, 774–776 dissolving precipitates and, 787–789 fractional precipitation and, 781–784 simultaneous equilibria and, 784–786 solubility product constant, Ksp and, 772–774 uses of K sp, 776–781 Ionic hydride An ionic compound that contains the hydride ion, H2, 196, 206 Ionic radii periodicity and, 188–190, 189i Ionic radius The radius of an ion, 206 Ionic solid, 252, 479t, 484–486, 484i, 492i Ion–ion interactions, 452–453, 452t Ionization In aqueous solution, the process in which a molecular compound separates to form ions, 212, 243, 367 electrolytes and extent of, 212–213 Ionization constant An equilibrium constant for the ionization of a weak electrolyte, 713, 736 for weak bases, A14 Ionization energy The amount of energy required to remove the most loosely held electron of an isolated gaseous atom or ion, 206 periodicity and, 184–186, 184i Ionization isomers Isomers that result from the interchange of ions inside and outside the coordination sphere, 916–917, 928 Ion product for water An equilibrium constant for the ionization of water, K w [H3O1][OH2] 1.0 10214 at 258C, 705–706, 736 Ions See also Liquid state of matter Iron metallurgy of, 851–853, 851i, 852t Isoelectronic Having the same number of electrons, 188, 206, 253 Isolated yield See Actual yield Isomers Different compounds that have the same formula, 928, 1025, 1036 alkanes and, 974 stereoisomers and, 919–923, 920i, 922i, 923i structural isomers and, 916–918 Isomorphous Refers to crystals having the same atomic arrangement, 478, 493 Isotopes Two or more forms of atoms of the same element with different masses; that is, atoms containing the same number of protons but different numbers of neutrons, 127–128, 127t, 131t, 167 See also Nuclear chemistry nuclear fission and, 957 Joliot, Frederick, 936 Joliot-Curie, Irene, 936 Joule ( J) A unit of energy in the SI system One joule is kg ? m2/s2, which is also 0.2390 cal, 36, 40 K c Equilibrium constant with amounts of reactants and products expressed as molar concentrations, 694 Kelvin (absolute) temperature, 35, 409, 411–412 Kelvin, Lord, 409 Ketone A compound in which a carbonyl group is bound to two alkyl or two aryl groups, or to one alkyl and one aryl group, 1000–1002, 1001i, 1025 and oxidation of secondary alcohols, 1047–1048 in summary of functional groups, 1013i Ketose A monosaccharide that contains a ketone group, 1053, 1064 Kilogram, 20, 20t Kinetic energy Energy that matter possesses by virtue of its motion, 4, 40, 595 See also Chemical kinetics intermolecular/intramolecular forces and, 450–451, 456–457 kinetic–molecular theory and, 432 Kinetic–molecular theory A theory that attempts to explain macroscopic observations of gases in microscopic or molecular terms, 428–433, 429i, 430t–431t, 438 K p Equilibrium constant with amounts of reactants and products expressed as partial pressures, 685, 687–689, 691–692, 694 Krypton, 881t Lactic acid, 1008t Lanthanides Elements 58 through 71 (after lanthanum), 206 Lattice, 476, 478 Lattice point, 476 Laue, Max von, 125 Laughing gas, 896 Lauric acid, 1005t Law of Conservation of Energy Energy cannot be created or destroyed in a chemical reaction or in a physical change; it may be changed from one form to another, 40, 551, 595 matter/energy and, 4–5 Law of Conservation of Matter No detectable change occurs in the total quantity of matter during a chemical reaction or during a physical change, 40, 93 matter/energy and, 1i, Law of Conservation of Matter and Energy The combined amount of matter and energy in the universe is fixed, 5, 40 Law of Constant Composition, 78 See Law of Definite Proportions Law of Definite Proportions Different samples of any pure compound contain the same elements in the same proportions by mass; also known as the Law of Constant Composition, 40, 49, 78 Law of heat summation, 561–565, 564i bond energies and, 566 Law of Multiple Proportions When two elements, A and B, form more than one compound, the ratio of the masses of element B that combine with a given mass I-13 of element A in each of the compounds can be expressed by small whole numbers, 72–73, 78 Lawrence, E O., 954 Lead storage battery A secondary voltaic cell that is used in most automobiles, 830–831, 830i, 833 LeChatelier’s Principle A system at equilibrium, or striving to attain equilibrium, responds in such a way as to counteract any stress placed upon it, 461, 493, 672–675, 745 LeChatelier’s Principle If a stress (change of conditions) is applied to a system at equilibrium, the system shifts in the direction that reduces the stress, to move toward a new state of equilibrium, 694 Leclanché cell A common type of dry cell (battery), 833 Leveling effect The effect by which all acids stronger than the acid that is characteristic of the solvent react with the solvent to produce that acid; a similar statement applies to bases The strongest acid (base) that can exist in a given solvent is the acid (base) characteristic of that solvent, 367 Levorotatory Refers to an optically active substance that rotates the plane of plane-polarized light to the left (counterclockwise); also called levo, 922, 923i, 928 Lewis, G N., 363 Lewis acid Any species that can accept a share in an electron pair to form a coordinate covalent bond, 270, 280, 364, 367 ligands and, 912 transition metals and, 909t Lewis base A substance that makes available a share in an electron pair, 280, 367 Lewis dot formula, 251–252, 252t Lewis dot representations, 251–252, 252t Lewis formula The representation of a molecule, ion, or formula unit by showing atomic symbols and only outer-shell electrons; does not represent the shape of the molecule or ion Each bonding electron pair can be represented by a pair of dots (the Lewis dot formula) or by a dash (the Lewis dash formula), 251–252, 252t, 280, 322 linear electronic geometry (AB2 species) and, 295 for molecules/polyatomic ions, 261–262 octahedral electronic geometry and, 314 octet rule for, 262–268 tetrahedral electronic geometry (AB2U2 species) and, 308, 310 tetrahedral electronic geometry (AB3U species) and, 304–305 tetrahedral electronic geometry (AB4 species) and, 299–300 trigonal bipyramidal electronic geometry (AB5, AB4U, AB3U2, AB2U3 species) and, 310–313 trigonal planar electronic geometry (AB3 species) and, 297–298 Lewis theory aqueous solution and, 362–365 www.elsolucionario.net GLOSSARY/INDEX www.elsolucionario.net GLOSSARY/INDEX Ligand A Lewis base in a coordination compound 788–789, 908, 928 coordination spheres and, 913t donor atoms and, 912t steric effects of, 915 strong/weak field ligand, 925 Ligand, Lewis bases and, 912 “Like dissolves like,” 506 Lime, 203 Limitations of octet rule, 270–274 Limiting reactant (reagant) A substance that stoichiomet rically limits the amount of product(s) that can be formed in a reaction, 110, 757 chemical equations and, 96–99 Linear A term used to describe the electronic geometry around a central atom that has two electron groups Also used to describe the molecular geometry of a molecule or polyatomic ion that has one atom in the center bonded to two atoms on opposite sides (180°) of the central atom (AB2 or AB2U3), 322 Linear accelerator A device used for accelerating charged particles along a straight-line path, 954–955, 955i, 964 Linear electronic geometry (AB2 species), 295–297, 316–317t Line spectrum An atomic emission or absorption spectrum, 167 Linkage isomers Isomers in which a particular ligand bonds to a metal ion through different donor atoms, 917–918, 928 Liquid aerosol A colloidal dispersion of a liquid in a gas, 541 Liquid state of matter, 9–10, 10i boiling points/distillation and, 463, 463i capillary action and, 459–460, 459i characteristics of, 450t compared with solids/gases, 401–402, 401t dipole–dipole interactions and, 452–453, 453i dispersion forces and, 454–456, 455i, 456t evaporation and, 460–461, 460i heat transfer and, 463–467, 464t hydrogen bonding and, 453–454, 454i intermolecular/intramolecular forces and, 450–451, 456–457 ion–ion interactions and, 451–452, 452t kinetic–molecular description of, 449–450, 450i, 450t, 451i surface tension and, 458–459, 459i vapor pressure and, 461–462, 462i, 462t viscosity and, 457–458, 458i Lithium as Group 1A metal, 865 Livingston, M S., 954 London, Fritz, 454 London forces See Dispersion forces Lone pair A pair of electrons residing on one atom and not shared by other atoms; unshared pair, 280, 288, 306, 310, 317 trigonal bipyramidal electronic geometry and, 312–313 Los Alamos National Laboratory, 962 Lowry, T M., 350 Low spin complex A complex in which the crystal field splitting energy is greater than the pairing energy, so that there are the same number or fewer unpaired d electrons on the metal atom than when the metal is uncomplexed In an octahedral low spin complex, pairing occurs to fill the t2g orbitals before any electrons occupy the eg orbitals, 925–926, 928 MacKinnon, Roderick, 1061 Macroscale, Magnesium as Group 2A metal, 868 metallurgy of, 848–849, 848i, 849i Magnetic quantum number (mO) Quantum mechanical solution to a wave equation that designates the particular orbital within a given subshell (s, p, d, i ) in which an electron resides The px , py, and pz orbitals have different magnetic quantum numbers, 152, 167 Magnitude, 292 Malic acid, 1008t Malleable substance, 489 Manometer A two-armed barometer See Illustrations 12-1, 403, 403i, 438 Mass A measure of the amount of matter in an object Mass is usually measured in grams or kilograms, 4, 20, 20–21t, 24i, 40, 936t of atoms, 60 of common elements, 58t of molecules, 63 of solute, 103–105 volume relationship with, 426–428 Mass action expression For a reversible reaction, aA bB N cC dD the product of the molar concentrations of the products (species on the right), each raised to the power that corresponds to its coefficient in the balanced chemical equation, divided by the product of the concentrations of the reactants (species on the left), each raised to the power that corresponds to its coefficient in the balanced chemical equation At equilibrium the mass action expression is equal to K; at other conditions, it is Q, 668, 694 Mass deficiency The amount of matter that would be converted into energy if an atom were formed from constituent particles, 937–938, 964 Mass number The integral sum of the numbers of protons and neutrons in an atom, 127–128, 127i, 167 Mass spectrometer An instrument that measures the chargeto- mass ratios of charged particles, 128–131, 129i, 167 Matter Anything that has mass and occupies space, 40 chemical/physical changes and, 12–13 chemical/physical properties of, 10–12, 14i defined, 4–5 density/specific gravity and, 31–34 fundamental particles of, 6t heat/temperature and, 34–36 heat transfer/heat measurement and, 36–39 and measurements in chemistry, 19–20 mixtures/substances/compounds/elements and, 13–19 percentages and, 31 states of, 9–10 unit factor method (dimensional analysis) and, 27–31 and units of measurement, 20–22 and use of numbers, 22–26 McMillan, E M., 956 Mean-square speed, 432 Measurement density/specific gravity and, 31–34 energy conversion, 30 mass conversion, 4, 20–21t, 29, 40 matter and, 19–22 percentages and, 31 unit conversions, 28 units of, 19t volume, 21, 21t, 24i, 29–30 Melting point The temperature at which liquid and solid coexist in equilibrium; also the freezing point, 467–468, 493 Mendeleev, Dmitri, 133–134, 134i, 136, 179 Meniscus The upper surface of a liquid in a cylindrical container, 459, 493 Metal An element below and to the left of the stepwise division (metalloids) of the periodic table; about 80% of the known elements are metals, 167, 243 Metallic bonding Bonding within metals due to the electrical attraction of positively charged metal ions for mobile electrons that belong to the crystal as a whole, 479–484, 479t, 480i, 487–488, 493 Metallic character, 137 Metallic conduction Conduction of electric current through a metal or along a metallic surface, 833 Metalloids Elements with properties intermediate between metals and nonmetals: B, Si, Ge, As, Sb, Te, Po, and At, 137–138, 137t, 167, 243 Metallurgy The overall processes by which metals are extracted from ores, 842–843, 843t, 855 aluminum, 849–851, 850i copper, 853–854, 853i, 854i gold, 855 iron, 851–853, 851i, 852t magnesium, 848–849, 848i, 849i and occurance of metals, 842 and pretreatment of ores, 843–845, 844i and reduction to free metals, 845–846, 845t, 847t and refining of metals, 846–848, 847i Metal oxides, 366 Metals, 137, 137t ionic compounds and, 253–256 Metastable, 511 Metathesis reaction A reaction in which the positive and negative ions in two compounds “change partners,” with no change in oxidation numbers, to form two new compounds, 235–240, 243 summary/characteristics of, 242t Meter, 21, 21t Methane chemical equation with oxygen, 87–88 as natural gas component, physical properties of, 12t www.elsolucionario.net I-14 www.elsolucionario.net GLOSSARY/INDEX of millimoles of solute per milliliter of solution, 103–105, 110, 383, 392 aqueous acid–base reactions and, 375–379 as unit factor, 108 Molar mass The mass, in grams, of one mole of a substance; numerically equal to the formula weight of the substance See Formula weight; see Molecular weight, 78 Molar solubility The number of moles of a solute that dissolve to produce a liter of saturated solution, 789 solubility product constant, Ksp and, 775–777, 775i Mole 6.022 1023 (Avogadro’s number of ) formula units (or molecules, for a molecular substance) of a substance The mass, in grams, of one mole is numerically equal to the formula (molecular) weight of the substance, 56–61, 63, 78 of common molecular substances, 62t Molecular formula A formula that indicates the actual number of atoms present in a molecule of a molecular substance Compare with Simplest (empirical) formula, 71–73, 78, 419–420 Molecular geometry The arrangement of atoms (not pairs of electrons) around a central atom of a molecule or polyatomic ion, 321t, 322 Molecular hydride A compound in which hydrogen shares electrons with an atom of another nonmetal, 195–196, 206 Molecular orbital (MO) An orbital resulting from overlap and mixing of atomic orbitals on different atoms An MO belongs to the molecule as a whole), 330–332, 337t, 343 Molecular orbital theory A theory of chemical bonding based on the postulated existence of molecular orbitals, 260, 330, 343 procedure for, 335 Molecular quantities, 432 Molecular weight The mass, in atomic mass units, of one molecule of a non-ionic (molecular) substance Numerically equal to the mass, in grams, of one mole of such a substance This number is obtained by adding the atomic weights of the atoms specified in the formula, 61–62, 79, 418–419 determination by freezing point determination/ boiling point elevation of, 525–526 from osmotic pressure, 532–533 Molecule The smallest particle of an element or compound that can have a stable independent existence, 40 matter/energy and, Mole fraction The number of moles of a component of a mixture divided by the total number of moles in the mixture, 422–423, 439, 515 Mole fraction of a component in solution The number of moles of the component divided by the total number of moles of all components, 541 Mole or reaction (mol rxn), 555–558, 595 Mole ratios, 93 Molten sodium chloride electrolysis of, 797–798, 798i, 803 Momentum, 431–433 Monatomic ion An ion that consists of only one atom, 252, 280 Monodentate Describes ligands with only one donor atom, 912, 928 Monomers The small molecules from which polymers are formed, 1020, 1022t, 1025, 1064 Monoprotic acid An acid that can form only one hydronium ion per molecule; may be strong or weak, 237, 359, 736 ionization constant for, 710–723, 711t Monosaccharide Simple sugars (monomers) from which more complex carbohydrates are constructed, 1053–1054, 1054i, 1054t, 1064 Moseley, H G J., 125–126 Nanoscale, Nanotechnology, 990 Naphthalene, 992, 992t, 993i National Institute of Science and Technology, 8i Native ore A metal that occurs in an uncombined or free state in nature, 842, 855 Natural radioactivity Spontaneous decomposition of an atom, 167 Negative deviation, 519–520, 519i Neon, 881t Nernst equation An equation that corrects standard electrode potentials for nonstandard conditions, 819–823, 833 Net ionic equation An equation that results from canceling spectator ions from a total ionic equation, 219, 243, 367, 387–388 Neutralization The reaction of an acid with a base to form a salt and (usually) water; usually, the reaction of hydrogen ions with hydroxide ions to form water molecules, 367 acidic salts and, 362 coordinate covalent bond formation and, 363 Neutralization reaction The reaction of an acid with a base to form a salt Often, the reaction of hydrogen ions with hydroxide ions to form water molecules, 236–238, 243, 363–364 and acids in daily lives, 732 aqueous solution and, 359–361 buffer solutions and, 755–757 Neutron–proton ratio/nuclear stability nuclear chemistry and, 936–937, 937i Neutrons A subatomic nuclear particle having a mass of 1.0087 amu and no charge, 6t, 120–121, 121t, 126–127, 167, 936t artificial transmutations and, 955–956 as fundamental particles, nuclei and, 937i nuclides and, 936t Newlands, J A R., 179 Newton (N), 405 Newton, Isaac, 139–140 Nickel–cadmium cell (nicad battery) A dry cell in which the anode is Cd, the cathode is NiO2, and the electrolyte is basic, 831, 833 Nicotine, 1003 Nitration, 1016 www.elsolucionario.net Method of initial rates A method of determining the rate-law expression by carrying out a reaction with different initial concentrations and analyzing the resulting changes in initial rates, 616–621, 651 Methylbutane, 1036 Metric conversion, 29–31 Meyer, Lothar, 133, 179 Micelle A cluster of a large number of soap or detergent molecules or ions, assembled with their hydrophobic tails directed toward the center and their hydrophilic heads directed outward, 538, 539i, 541 Millikan, Robert, 121 Millimole, 376–377, 383 1/1000 mole, 392 Mineral A naturally occurring inorganic solid substance having a definite chemical composition and characteristic crystalline structure, 855 Mineral acids, 215 Mirror images, 1040i See Optical isomers Miscibility The ability of one liquid to mix with (dissolve in) another liquid, 508, 533, 541 Miscible gases, 402 Miscible liquids, 449, 508–509, 508i, 509i, 533 Mixture A sample of matter composed of variable amounts of two or more substances, each of which retains its identity and properties, 14i, 40 matter and, 13–19 standard entropy change, ∆S and, 583–584, 584i MO theory See Molecular orbital theory Moderator A substance such as hydrogen, deuterium, oxygen, or paraffin capable of slowing fast neutrons upon collision, 959, 964 Molality (m) Concentration expressed as number of moles of, 514–515, 541 Molar enthalpy of vaporization See Molar heat of vaporization Molar heat capacity The amount of heat necessary to raise the temperature of one mole of a substance one degree Celsius with no change in state; usually expressed in kJ/mol ? °C See Specific heat, 463, 493 Molar heat of condensation The amount of heat that must be removed from one mole of a vapor at its condensation point to condense the vapor with no change in temperature; usually expressed in kJ/mol See Heat of condensation, 493 Molar heat of fusion The amount of heat required to melt one mole of a solid at its melting point with no change in temperature; usually expressed in kJ/mol See Heat of fusion, 468–469, 469t, 493 Molar heat of vaporization The amount of heat required to vaporize one mole of a liquid at its boiling point with no change in temperature; usually expressed in kJ/ mol See Heat of vaporization, 463–464, 464t, 493 Molarity (M ) The number of moles of solute per liter of solution or the number I-15 www.elsolucionario.net GLOSSARY/INDEX Nitrogen homonuclear diatomic molecules and, 336 hydrogen compounds of, 895–896 nitrogen oxides, 896–898 occurence of, 894–895 oxoacids of, 898–900, 900i properties of, 893–894, 893t–894t Nitrogen cycle The complex series of reactions by which nitrogen is slowly but continually recycled in the atmosphere, lithosphere, and hydrosphere, 895, 903 Nitrogen fixation, 895 Nobel, Alfred, 1017 Noble (rare) gases Elements of periodic Group 8A; also called rare gases; formerly called inert gases, 137, 167, 178, 206, 243, 903 occurence/use/properties of, 880–881, 880t–881t xenon compounds, 881–882, 882t Noble gas configuration The stable electron configuration of a noble gas, 206 Nodal plane (node) A region in which the probability of finding an electron is zero, 332, 343 Node, 151 Nomenclature of coordination compounds, 914 Nonbonding molecular orbital A molecular orbital derived only from an atomic orbital of one atom; lends neither stability nor instability to a molecule or ion when populated with electrons, 340, 343 Nonelectrolyte Compounds that not ionize (or dissociate into their constituent ions) when dissolved in water to produce aqueous solutions that will not conduct an electric current, 212, 243, 367, 704–705, 736 Nonmetallic character, 137 Nonmetals Elements above and to the right of the metalloids in the periodic table, 137, 137t, 167, 96, 243 displacement reactions and, 234 hydroxyl compounds of, 357 ionic compounds and, 253–256 reactions of metal oxides with, 202–203 reactions of oxygen with, 200–201 ternary acids and, 222–223 Nonpolar bond A covalent bond between two atoms with the same electronegativity, so that the electron density is symmetrically distributed, 276–277, 280 Nonspontaneous change, 595 electrolytic cells and, 796 Nonvolatile acids, 365 Normal boiling point The temperature at which the vapor pressure of a liquid is equal to one atmosphere pressure, 463–464, 493 Normal melting point The melting (freezing) point at one atmosphere pressure, 468, 493 Normal oxide A metal oxide containing the oxide ion, O22 (oxygen in the 22 oxidation state), 198–199, 206 Normal salt A salt that contains no ionizable H atoms or OH groups, 361–362, 367 Nuclear binding energy The energy equivalent of the mass deficiency; energy released in the formation of an atom from subatomic particles, 938–940, 940i, 965 Nuclear chemistry and artificial transmutation of elements, 953–956, 954i, 955i binding energy/nuclear stability and, 937–940 decay series and, 948, 948i historical aspects of, 935–936 management of nuclear waste, 962–963 neutron-poor nuclei (below band of stability), 942–943 neutron-proton ratio/nuclear stability and, 936–937, 936t, 937i neutron-rich nuclei (above band of stability), 942 nuclear fission and, 956–958, 957i, 958i nuclear fission reactors and, 958–961, 958i nuclear fusion and, 961–964 nuclear reaction equations, 941–942 and nuclei with atomic number 83, 943–944 nucleus and, 936, 936t and radiation detection, 944–945, 945i radioactive decay and, 940–941, 941t rates of decay/half-lives and, 946–947, 947i and uses of radionuclides, 948–953, 949t Nuclear fission The process in which a heavy nucleus splits into nuclei of intermediate masses and one or more neutrons are emitted, 935, 956–958, 957i, 958i, 965 Nuclear fusion The combination of light nuclei to produce a heavier nucleus, 935, 961–964, 965 Nuclear reaction A reaction involving a change in the composition of a nucleus; it can evolve or absorb an extraordinarily large amount of energy, 935, 965 equations for, 942–943 first, 953 Nuclear reactor A system in which controlled nuclear fission reactions generate heat energy on a large scale The heat energy is subsequently converted into electrical energy, 958–961, 965 Nuclear waste, 962–963 Nucleic acid A biopolymer consisting of repeating units of ribose or deoxyribose, phosphate, and selected bases, 1062–1064, 1062i, 1063i, 1064 Nucleons Particles comprising the nucleus; protons and neutrons, 957, 965 Nucleotide bases, 1004 Nucleus The very small, very dense, positively charged center of an atom containing protons and neutrons, except for H, 124–125, 167, 936 Nuclides Different atomic forms of all elements (in contrast to isotopes, which are different atomic forms of a single element), 936, 936t, 965 A Nuclide symbol The symbol for an atom, Z E, in which E is the symbol for an element, Z is its atomic number, and A is its mass number, 127, 168 Numbers, 21t matter and, 22–26 Nylon, 1023–1024 Oceanic resources, 15 Octahedral A term used to describe the electronic geometry around a central atom that has six electron groups Also used to describe the molecular geometry of a molecule or polyatomic ion that has one atom in the center bonded to six atoms at the corners of an octahedron (AB6), 294t, 314–315, 317t, 321t, 322 Octahedral electronic geometry, 314–317 Octahedron (regular) A polyhedron with eight equal-sized, equilateral triangular faces and six apices (corners), 322 Octane number, 982 Octet rule Many representative elements attain at least a share of eight electrons in their valence shells when they form molecular or ionic compounds; this rule has some limitations, 262–268, 280 limitations of, 270–274 Oil A liquid triester of glycerol and unsaturated fatty acids, 1010, 1012, 1025 Oil-drop experiment, 121–122, 122t Oligosaccharide A molecule consisting of four to ten monosaccharides joined together by glycosidic bonds, 1055, 1064 Optical activity The ability of one of a pair of optical isomers to rotate the plane of polarized light, 922, 928, 1039, 1064 Optical isomers Molecules that are nonsuperimposable mirror images of each other, that is, that bear the same relationship to each other as left and right hands; also called enantiomers, 1064 See Enantiomers Orbital Each allowed wave description of a stable state for an electron in an atom; a region of space in which the probability of finding an electron is high, 168 crystal field theory and, 924 Orbital approximation, 157 Orbital notation, 161 Order of a reactant The power to which the reactant’s concentration is raised in the rate-law expression, 651 Order of a reaction The sum of the powers to which all concentrations are raised in the rate-law expression; also called the overall order of a reaction, 615, 631–632, 636, 651 Ore A natural deposit containing a mineral of an element to be extracted, 842, 851, 855 Organic chemistry The study of carboncontaining compounds that contain C i C or C i H bonds and sometimes a few other elements such as oxygen, nitrogen, sulfur, phosphorus, and the halogens, 3, 971–973, 972t, 1026 addition reactions and, 1017–1019 alcanes/cycloalkanes (saturated hydrocarbons) and, 973–978, 974i, 975i, 976t–977t alkenes (unsaturated hydrocarbons) and, 982–987, 982i, 984i alkynes and, 987–989 biopolymers and, 1052–1053 carbohydrates and, 1053–1056, 1053i, 1054i, 1054t, 1055i, 1055t, 1056i www.elsolucionario.net I-16 www.elsolucionario.net conformations and, 1041–1042, 1042i constitutional isomers and, 1036–1037 elimination reactions and, 1019–1020 and formation of carboxylic acid derivative, 1050–1051 functional groups, 993–1013 See also under Functional group and hydrolysis of esters, 1052–1052 nucleic acids and, 1062–1064, 1062i, 1063i oxidation–reduction reactions and, 1045–1050, 1049t petroleum and, 983 polymerization reactions and, 1020–1024, 1022t polypeptides/proteins and, 1057–1061, 1058t, 1059i, 1060t stereoisomers and, 1037–1041, 1038i, 1039i substitution reactions and, 1014–1017 summary of functional groups, 1013i Organic chemistry Brønsted–Lowry acid/ base reactions and, 1043–1045, 1045t Organic compounds, 49 Organic halides, 994–996, 995t Origin and Names of Chemical Elements (Ringnes), 67 Osmosis The process by which solvent molecules pass through a semipermeable membrane from a dilute solution into a more concentrated solution, 541 Osmotic pressure The hydrostatic pressure produced on the surface of a semipermeable membrane by osmosis, 541 colligative properties (of solutions) and, 530–533, 530i Ostwald process An industrial process for the production of nitrogen oxide and nitric acid from ammonia and oxygen, 903 Ostwald viscometer, 458 Overlap of orbitals The interaction of orbitals on different atoms in the same region of space, 288, 322 Oxalic acid, 1008t Oxidation An increase in oxidation number; corresponds to a loss of electrons, 225, 243, 392 of alkylbenzenes, 1048–1049 (as applied to organic compounds) The increase of oxygen content or the decrease of hydrogen content of an organic molecule, 1064 and combustion of organic compounds, 1049–1050 nitrogen states of, 894t of organic species, 1045–1050 and ozone in the environment, 648–649 Oxidation numbers See Oxidation states Oxidation–reduction reaction A reaction in which oxidation and reduction occur; also called a redox reaction, 225–228, 243, 392, 1045–1050, 1049t adding H1, OH2, H2O to balance, 387–389 balancing of, 386 d-transition metals and, 874 electrochemistry and, 795 summary/characteristics of, 242t titration calculations for, 389–392 Oxidation states (numbers) Arbitrary numbers that can be used as aids in writing formulas and balancing equations; for single-atom ions they correspond to the charge on the ion; less metallic elements are assigned negative oxidation states in compounds and ions, 206, 243 d-transition metals and, 873–874, 874t periodicity and, 192–194, 194t Oxide A binary compound of oxygen, 206, 890–892 periodicity and, 198–205, 199t, 200i, 204t Oxidizing agent The substance that oxidizes another substance and is reduced, 226, 243, 392 Oxoacid, 892–893 See Ternary acid Oxygen chemical equation with methane, 87–88 combustion reaction and, 203–205 and dissolution of gases in liquids, 509 homonuclear diatomic molecules and, 336–338 periodicity and, 198–205, 199t, 200i, 204t physical properties of, 12t redox equation balancing and, 387–389 ternary acids and, 222–223 Ozone, 198 Pairing energy The energy required to pair two electrons in the same orbital, 925, 928 Pairing of electrons Interaction of two electrons with opposite ms values in the same orbital ( cT ) Also known as spin pairing, 156, 168 Palmitic acid, 1005t PANs (peroxyl nitrates) Abbreviation for peroxyacyl nitrates, photochemical oxidants in smog, 898, 903 Paramagnetism Attraction toward a magnetic field, stronger than diamagnetism, but still very weak compared with ferromagnetism; due to presence of unpaired electrons, 166, 166i, 168 Parent nuclide A nuclide that undergoes nuclear decay, 948, 965 Partial pressure The pressure exerted by one gas in a mixture of gases, 421–426, 439, 679–681, 687 Particulate matter Finely divided solid particles suspended in air, 204, 903 Pascal (Pa) The SI unit of pressure; it is defined as the pressure exerted by a force of one newton acting on an area of one square meter, 405, 439 Pauli Exculsion Principle No two electrons in the same atom may have identical sets of four quantum numbers, 159, 168, 333 Pauling scale, 190–191, 191t Pentane, 1036 Peptide Compounds formed by the linking of small numbers of amino acids, 1057, 1064 Peptide bond A bond formed by elimination of a molecule of water between the amino group of one amino acid and the carboxylic acid group of another, 1024, 1026, 1057, 1064 Percentages matter and, 31 I-17 Percent by mass, 102 100% multiplied by the mass of a solute divided by the mass of the solution in which it is contained, 110 Percent composition The mass percentage of each element in a compound, 64–65, 69–71, 79 Percent ionization of weak electrolytes The percent of the weak electrolyte that ionizes in a solution of a given concentration, 541 Percent purity The mass percentage of a specified compound or element in an impure sample, 77–78, 79 Percent yield, 99 100% times actual yield divided by theoretical yield, 110 Period The elements in a horizontal row of the periodic table, 136, 168 Periodicity Regular periodic variations of properties of elements with atomic number (and position in the periodic table), 168, 206 atomic radii and, 181–183, 182i electron affinity (EA) and, 186–188, 187i electronegativity (EN) and, 190–192, 191t hydrogen/hydrides reactions and, 194–197, 195i ionic radii and, 188–190, 189i ionization energy and, 184–186, 184i oxidation states and, 192–194, 194t oxygen/oxides reactions and, 198–205, 199t, 200i, 204t periodic table and, 178–181 Periodic law The properties of the elements are periodic functions of their atomic numbers, 168, 178, 206 Periodic table An arrangement of elements in order of increasing atomic number that also emphasizes periodicity, 164i, 165i, 165t, 168 electron configurations and, 163–166 Germanium, 135t Mendeleev’s early, 134i metals/nonmetals/metalloids of, 133–138 periodicity and, 178–181 Permanganate solutions, 389–392 Peroxide A compound containing oxygen in the 21 oxidation state Metal peroxides contain the peroxide ion, O222, 198–199, 206 Petroleum, 982, 1023 pH The negative logarithm of the concentration (mol/L) of the H3O1 (or H1) ion; the commonly used scale ranges from to 14, 707–710, 709t, 710i, 736, 760i, 761i See also Buffers calculation of pKa from, 713 range for common substances, 709 and salts of weak bases/strong acids, 730–731 pH meter A device to measure the pH of a solution; typically consists of a pHdependent glass electrode and a reference electrode (often a saturated calomel electrode), 833 Phase diagram A diagram that shows equilibrium temperature–pressure relationships for different phases of a substance, 470–473, 471i, 472t, 473i, 493 www.elsolucionario.net GLOSSARY/INDEX www.elsolucionario.net GLOSSARY/INDEX Phenanthrene, 992, 992t, 993i Phenol, 720 Phenol A hydrocarbon derivative that contains an i OH group bound to an aromatic ring, 996–999, 996i, 997i, 999t, 1026 in summary of functional groups, 1013i Phenylalanine, 1039–1041 Pheromones, 1046 Phosphorus, 142–143, 900–901 discovery of, 180 Photochemical oxidants Photochemically produced oxidizing agents capable of causing damage to plants and animals, 903 Photochemical smog A brownish smog occurring in urban areas that receive large amounts of sunlight; caused by photochemical (light-induced) reactions among nitrogen oxides, hydrocarbons, and other components of polluted air that produce photochemical oxidants, 898, 903 Photoelectric effect Emission of an electron from the surface of a metal, caused by impinging electromagnetic radiation of certain minimum energy; the resulting current increases with increasing intensity of radiation, 142i, 168 Photographic radiation detection, 944 Photon A “packet” of light or electromagnetic radiation; also called a quantum of light, 141–142, 168 Photon Planck equation and, 147–148 Phthalic acid, 382 Physical change A change in which a substance changes from one physical state to another, but no substances with different compositions are formed, 11i, 40 matter and, 11t, 12–13 Physical chemistry defined, Physical properties of common substances, 12t of matter, 10–12, 10i of metals/nonmetals, 137t of water, 12i Pi (p) bond A bond resulting from the side-on overlap of atomic orbitals, in which the regions of electron sharing are on opposite sides of and parallel to an imaginary line connecting the bonded atoms, 318, 322, 343 chemical bond formed by the side-to-side overlap of atomic orbitals, 1026 Pi (p) molecular orbital A molecular orbital resulting from side-on overlap of atomic orbitals, 332, 333i, 343 Pig iron The iron obtained from the blast furnace, 852, 855 pK, 707 pK a The negative logarithm of K a, the ionization constant for a weak acid, 711–716, 736 and salts of weak bases/weak acids, 732–734 and salts of strong bases/weak acids, 727–728 and salts of weak bases/weak acids, 732–734 and autoionization of water, 705–706, 705t, 707 ionization constants and, 721–722 Planck, Max, 141 Planck equation, 147–148 Plane-polarized light Light waves in which all the electric vectors are oscillating in one plane, 928 Plasma A physical state of matter that exists at extremely high temperatures, in which all molecules are dissociated and most atoms are ionized, 963, 965 pOH The negative logarithm of the concentration (mol/L) of the OH2 ion; the commonly used scale ranges from 14 to 0, 707–710, 709t, 736 Poise, 457 Polar bond A covalent bond between two atoms with different electronegativities, so that the electron density is unsymmetrically distributed, 276–279, 280, 292–293, 293i Polarimeter A device used to measure optical activity, 923i, 928 Polarity, 288 Polarization dispersion forces and, 455 Polarization of an electrode Buildup of a product of oxidation or reduction at an electrode, preventing further reaction, 833 Polyamide A polymeric amide, 1023, 1026 Polyatomic ion, 252, 279 Polyatomic molecules Consisting of more than one atom Elements such as Cl2, P4, and S8 exist as polyatomic molecules Examples of polyatomic ions are the ammonium ion, NH41, and the sulfate ion, SO422, 7, 53–54, 79, 293i Polyatomic molecules covalent/ionic bonding and, 452 Polydentate Describes ligands with more than one donor atom, 912, 928 Polyene A compound that contains more than one double bond per molecule, 985, 1026 Polyester A polymeric ester, 1022–1023, 1026 Polyhydroxy base, 362 Polymerization The combination of many small molecules (monomers) to form large molecules (polymers), 1026, 1064 Polymerization reactions, 1020–1024, 1022t Polymers Large molecules formed by the combination of many small molecules (monomers), 1018, 1020–1024, 1026, 1064 Polymorphous Refers to substances that crystallize in more than one crystalline arrangement, 478, 493 Polyol An alcohol that contains more than one i OH group; a polyol with two i OH groups is called a glycol, 998, 1026 Polypeptide A polymer composed of amino acids linked by peptide bond, 1024s, 1026, 1057–1061, 1058t, 1059i, 1060t, 1064 Polyprotic acid An acid that can form two or more hydronium ions per molecule, 357, 362, 367, 723–726, 736 Polysaccharide Carbohydrates that contain more than ten monosaccharide units, 1055, 1064 p orbital Beginning with the second shell, a set of three degenerate, mutually perpendicular, equal-arm, dumbbell-shaped atomic orbitals per shell, 168 periodic table and, 165i quantum numbers and, 152, 155i Positive deviation, 519, 519i Positron A nuclear particle with the mass of an electron but opposite charge, 942–943, 952, 965 Positron emission See Electron capture, 942–943 Positron Emission Tomography (PET), 952 Post-transition metals Representative metals in the “p block,” 875 periodic trends of, 869–872, 869t, 870i Potassium–argon dating, 950 Potassium hydrogen phthalate, 382 Potential energy Energy that matter possesses by virtue of its position, condition, or composition, 4, 40, 595 Poyatomic ion An ion that consists of more than one atom, 280 Precipitate An insoluble solid that forms and separates from a solution, 238–240, 243, 789 dissolving of, 787–789 solubility product principle and, 779–781 Precipitation reaction A reaction in which a solid (precipitate) forms, 238–240, 243 concentration required for, 782–783 Precision How closely repeated measurements of the same quantity agree with one another, 24, 40 Pressure 403–406, 403i, 406i Boyle’s Law and, 406–409, 407i ∆H/∆E relationship and, 574–575 Force per unit area, 439 internal energy changes, ∆E and, 570–571 LeChatelier’s Principle and, 675–676 nonideal gas behavior and, 435 solubility and, 511–513, 513i van der Waals equation and, 437, 437t Pressure–volume work, 595 Primary alcohol An alcohol with no or one R group bonded to the carbon bearing the i OH group, 997–999, 999t, 1026, 1047–1048 Primary amine An amine in which one H atom of ammonia has been replaced by an organic group, 1003, 1026 Primary standard A substance of a known high degree of purity that undergoes one invariable reaction with the other reactant of interest, 380–381, 392 Primary structure The sequence of the monomeric units in proteins, carbohydrates, and so on, 1058, 1064 Primary voltaic cell A voltaic cell that cannot be recharged; no further chemical reaction is possible once the reactants are consumed, 833 dry cells and, 828–829, 828i Principal quantum number (n) The quantum mechanical solution to a wave equation that designates the main shell, or energy level, in which an electron resides, 152, 168 Prism, 139–140, 140i Product-favored change A change for which the collection of products is more stable www.elsolucionario.net I-18 www.elsolucionario.net than the collection of reactants under the given conditions; also called spontaneous change, 595 and aspects of spontaneity, 575–576, 576i energy/matter dispersal and, 576–579, 576i, 578i, 579i entropy/entropy change and, 580–586, 580i, 582i, 584i free energy change/spontaneity and, 588–591 Second Law of Thermodynamics and, 586–588, 587i, 588t and temperature dependence of spontaneity, 591–595, 593i, 593t Products Substances produced in a chemical reaction, 87, 110 Properties Characteristics that describe samples of matter Chemical properties are exhibited as matter undergoes chemical changes Physical properties are exhibited by matter with no changes in chemical composition, 40 Propionaldehyde, 1001t Propionic acid, 1005t Protein A naturally occurring polymeric chain of l-amino acids linked together by peptide bonds, 1024, 1026, 1057–1061, 1058, 1058t, 1059i, 1060t functions of, 1060t, 1064 Protic acid An Arrhenius acid, or a Brønsted–Lowry acid, 350, 367 Protons A subatomic particle having a mass of 1.0073 amu and a charge of 11, found in the nuclei of atoms, 6t, 120–121, 121t, 168, 936t as fundamental particles, nuclei and, 937i nuclides and, 936t Purity see Percent purity Quadratic equations, A4 ionic equilibria and, 715 simplifying, A4 and uses of equilibrium constant, K, 672 Qualitative analysis, 66 Quantitative analysis, 66 Quantum A “packet” of energy, 141 See Photon See Photon Quantum mechanics A mathematical method of treating particles on the basis of quantum theory, which assumes that energy (of small particles) is not infinitely divisible, 150–151, 168 Quantum numbers Numbers that describe the energies of electrons in atoms; they are derived from quantum mechanical treatment, 150, 151–152, 153t, 168 Quicklime, 203 Quinic acid, 1008t Racemic mixture A single sample containing equal amounts of the two enantiomers (optical isomers) of a compound; does not rotate the plane of polarized light, 922, 929, 1039, 1064 Radiant energy See Electromagnetic radiation Radiation High-energy particles or rays emitted in nuclear decay processes, 940, 941i, 965 detection of, 944–945, 945i Radical An atom or group of atoms that contains one or more unpaired electrons (usually very reactive species), 198, 206, 885, 903 and ozone in the environment, 649 Radioactive dating A method of dating ancient objects by determining the ratio of amounts of a parent nuclide and one of its decay products present in an object and relating the ratio to the object’s age via half-life calculations, 965 Radioactive tracer A small amount of radioisotope that replaces a nonradioactive isotope of the element in a compound whose path (e.g., in the body) or whose decomposition products are to be monitored by detection of radioactivity; also called a radiopharmaceutical, 951–952, 965 Radioactivity The spontaneous disintegration of atomic nuclei, 935, 965 Radiocarbon dating 948–951, 949t Radioisotope A radioactive isotope of an element, 965 Radionuclide A radioactive nuclide, 965 agricultural uses of, 952 industrial uses of, 952–953 medical uses of, 951–952 radioactive dating and, 948–951, 949t research uses of, 953 Radiopharmaceuticals, 951 Radon, 881t Raoult’s Law The vapor pressure of a solvent in an ideal solution is directly proportional to the mole fraction of the solvent in the solution, 516–520, 516i, 519i, 541 Rate constant An experimentally determined proportionality constant that is different for different reactions and that, for a given reaction, changes only with temperature or the presence of a catalyst; k in the ratelaw expression, rate k[A] x [B] y, 615, 651 Rate-determining step The slowest elementary step in a reaction mechanism; the step that limits the overall rate of reaction, 636, 651 Rate-law expression An equation that relates the rate of a reaction to the concentrations of the reactants and the specific rate constant; rate k[A]x[B]y The exponents of reactant concentrations not necessarily match the coefficients in the overall balanced chemical equation The rate-law expression must be determined from experimental data, 614–621, 627, 651 Rate of evaporation 467t Rate of reaction The change in concentration of a reactant or product per unit time, 607–613, 609i, 611t, 612i, 651 Rates of decay/half-lives, 946–947, 947i Reactant-favored change A change for which the collection of reactants is more stable than the collection of products under the given conditions; also called nonspontaneous change, 575, 595 Reactants Substances consumed in a chemical reaction, 87–88, 110 Reaction coordinate The progress along the potential energy pathway from reactants to products, 634f, 651 I-19 Reaction intermediate A species that is produced and then entirely consumed during a multistep reaction; usually shortlived, 637, 651 Reaction mechanism The sequence of fundamental steps by which reactants are converted into products, 635–638, 651 Reaction quotient, Q The mass action expression under any set of conditions (not necessarily equilibrium); its magnitude relative to K determines the direction in which reaction must occur to establish equilibrium, 667–668, 694 Reaction quotient (in precipitation reactions), Qsp The mass action expression that applies to the dissolution of a slightly soluble compound; this has the same algebraic form as that for K sp, except that the concentrations are not necessarily equilibrium ones, 789 Reaction ratio The relative amounts of reactants and products involved in a reaction; may be the ratio of moles, or masses, 93, 110, 375, 378–379 volume of solution and, 109 Reaction stoichiometry Description of the quantitative relationships among substances as they participate in chemical reactions, 110, 120 Reagent, see Limiting reactant (reagant) Redox reaction An oxidation–reduction reaction, 392 See also Oxidation– reduction reaction ion conversion to other species by, 787–788 Redox titration The quantitative analysis of the amount or concentration of an oxidizing or reducing agent in a sample by observing its reaction with a known amount or concentration of a reducing or oxidizing agent, 389–392 Reducing agent The substance that reduces another substance and is oxidized, 226, 243, 392 Reduction An algebraic decrease in oxidation number; may correspond to a gain of electrons, 225, 243, 392, 846t–847t, 1045 (as applied to organic compounds) The decrease of oxygen content or the increase of hydrogen content of an organic molecule, 1064 of carbonyl compounds, 1048 standard electrode potential for half-cell as, 811 Refining Purifying of a substance, 848, 855 Relative masses of reactants/products, 93 Representative elements The A group elements in the periodic table, 178, 206 Representative metals Metals in the A groups in the periodic table; their outermost electrons are in s and p orbitals, 873, 875 Resonance A concept in which two or more Lewis formulas for the same arrangement of atoms (resonance structures) are used to describe the bonding in a molecule or ion, 274–275, 280 Reverse osmosis The forced flow of solvent molecules through a semipermeable membrane from a concentrated solution into a dilute solution This is accomplished www.elsolucionario.net GLOSSARY/INDEX www.elsolucionario.net GLOSSARY/INDEX by application of hydrostatic pressure on the concentrated side greater than the osmotic pressure that is opposing it, 541 Reversible cells, 829 Reversible reaction A reaction that occurs in both directions; described with double arrows (m) The equal-length arrows not indicate equal amounts of reactants and products, just that some of each are present Chemists sometimes indicate the favored direction of a reversible reaction by using a longer arrow on top or bottom, 215, 243, 661–663, 665, 684–685, 690i, 694 Ribose The carbohydrate found in RNA, 1062, 1064 Ringnes, Vivi, 67 RNA Ribonucleic acid; a nucleic acid consisting of phosphate, ribose, and the four bases adenine, cytosine, guanine, and uracil, 1062–1063, 1062–1064, 1063i, 1064 Roasting Heating a compound below its melting point in the presence of air, 206, 845, 855 Root-mean-square speed The square root of the meansquare speed, "u2 This is equal to "3RT/M for an ideal gas The rootmean-square speed is slightly different from the average speed, but the two quantities are proportional, 439 Rubber, 1020–1021 Rutherford, Ernest, 123–125, 935, 953 Rutherford scattering experiment, 124i, 125i Rydberg, Johannes, 145 Rydberg constant, 145, A11 Sacrificial anode A more active metal that is attached to a less active metal to protect the less active metal cathode against corrosion, 833 Salt A compound that contains a cation other than H1 and an anion other than OH2 or O22, 213–214, 243, 360, 367 as essential compound in industrialized society, 236t with highly charged cations, 734–736, 736t neutralization reaction and, 237 oxoacids of halogens and, 887, 887t of strong base/strong acid, 727 of strong bases/weak acids, 727–730 of weak bases/strong acids, 730–731 of weak bases/weak acids, 731–734 Salt bridge A U-shaped tube containing an electrolyte that connects two half-cells of a voltaic cell, 803, 807, 833 Saponification The hydrolysis of esters in the presence of strong bases, 1051–1052, 1064 Saturated calomel electrode An electrode that consists of a platinum wire in contact with a paste of liquid mercury and solid mercury(I) chloride, Hg2Cl2(s), all immersed in a saturated solution of potassium chloride, KCl; often used as the reference electrode in a pH meter, 833 Saturated hydrocarbons Hydrocarbons that contain only single bonds They are also called alkanes or paraffin hydrocarbons, 973, 973i, 1026 alkanes/cycloalkanes (saturated hydrocarbons) and, 973–978, 974i, 975i, 976t–977t naming, 978–982, 979t Saturated solution A solution in which no more solute will dissolve at a given temperature, 541 and rates of dissolution, 510–511 solubility product constant, Ksp and, 772 Schrödinger, Erwin, 151 Schrödinger equation, 151 Scientific (natural) law A general statement based on the observed behavior of matter, to which no exceptions are known, 4, 40 Scientific notation, 22–23, A1–A3 See Exponential notation Scintillation counter A device used for the quantitative detection of radiation, 944, 965 Screening effect, 182 Secondary alcohol An alcohol with two R groups bonded to the carbon bearing the i OH group, 997, 1026, 1047–1048 Secondary amine An amine in which two H atoms of ammonia have been replaced by organic groups, 1003, 1026 Secondary standard A solution that has been titrated against a primary standard A standard solution is a secondary standard, 380, 392 Secondary voltaic cell A voltaic cell that can be recharged; the original reactants can be regenerated by reversing the direction of current flow, 829–832, 830i, 832i, 833 Second Law of Thermodynamics The universe tends toward a state of greater disorder in spontaneous processes, 586–588, 587i, 588t, 595 Second order reaction, 624–627 Seesaw A term used to describe the molecular geometry of a molecule or polyatomic ion that has four atoms bonded to a central atom and one lone pair on the central atom (AB4U), 313, 322 Selenium occurence/use/properties of, 889 Semiconductors A substance that does not conduct electricity at low temperatures but does so at higher temperatures, 138, 243, 489, 490–491, 493 Semipermeable membrane A thin partition between two solutions through which certain molecules can pass but others cannot, 530, 541 Sequential reaction A chemical process in which several reaction steps are required to convert starting materials into products, 110 chemical equations and, 100–101 Shielding effect Electrons in filled sets of s and p orbitals between the nucleus and outer shell electrons shield the outer shell electrons somewhat from the effect of protons in the nucleus; also called screening effect, 182, 206 SI (International System of Units), A8–A10 Side reactions, 99 Sigma (s) bond A bond resulting from the head-on overlap of atomic orbitals, in which the region of electron sharing is along and (cylindrically) symmetrical to an imaginary line connecting the bonded atoms, 318, 322, 343, 1026 Sigma (s) molecular orbital A molecular orbital resulting from head-on overlap of two atomic orbitals, 332, 343 Significant figures Digits that indicate the precision of measurements—digits of a measured number that have uncertainty only in the last digit, 23–26, 40 Silicon, 901–902 Simplest formula The smallest whole-number ratio of atoms present in a compound; also called empirical formula Compare with Molecular formula, 65–71, 79 Simultaneous equilibria, 784–786 Single bond A covalent bond resulting from the sharing of two electrons (one pair) between two atoms, 260–261, 280 average energies for, 566t Slag Unwanted material produced during smelting, 852, 854, 855 Slaked lime, 203 Slow neutron A fast neutron slowed by collision with a moderator, 956, 965 Smelting Chemical reduction of a metal from its ore by treating the molten ore with a reducing agent, 855 Soap An emulsifier that can disperse nonpolar substances in water; the sodium salt of a long-chain organic acid; consists of a long hydrocarbon chain attached to a carboxylate group, i CO22 Na1, 541, 1051–1052, 1064 Sodium as Group 1A metal, 865 Sodium chloride electrolysis of, 797–800, 798i, 799i, 803 Sol A colloidal dispersion of a solid in a liquid, 536, 541 Solid aerosol A colloidal dispersion of a solid in a gas, 541 Solid emulsion A colloidal dispersion of a liquid in a solid, 541 Solid foam A colloidal dispersion of a gas in a solid, 541 Solidification, 450 Solid sol A colloidal dispersion of a solid in a solid, 541 Solid state of matter, 9–10, 10i amorphous/crystalline, 473–476, 474i, 476i and band theory of metals, 487–492, 488i, 489i, 492i bonding in metallic solids, 479–484, 479t, 480i characteristics of, 450t compared with liquids/gases, 401–402, 401t covalent solids and, 486–487, 487i crystal structures and, 476–479, 476i, 477t, 478i dipole–dipole interactions and, 452–453, 453i dispersion forces and, 454–456, 455i, 456t heat transfer involving, 468–470, 469t hydrogen bonding and, 453–454, 454i intermolecular/intramolecular forces and, 450–451, 456–457 ionic solids and, 484–486, 484i, 492i ion–ion interactions and, 451–452, 452t www.elsolucionario.net I-20 www.elsolucionario.net kinetic–molecular description of, 449–450, 450i, 450t, 451i melting point and, 467–468 molecular solids and, 486, 486i phase diagrams and, 470–473, 471i, 472t, 473i semiconductors and, 490–491 sublimation/vapor pressure of, 470, 470i Solubility See also Solubility product principle bonding/electrolyte characteristics and, 219t and compounds in aqueous solution, 216– 217, 217t effect of pressure on, 511–513, 513i effect of temperature on, 511–513, 512i precipitation reactions and, 240 simultaneous equilibria and, 784–786 Solubility product constant, Ksp The equilibrium constant that applies to the dissolution of a slightly soluble, 775i, 789, A17–A18 determination of, 774–776 solubility product principle and, 772–774 uses of, 776–781 Solubility product principle The solubility product constant expression for a slightly soluble compound is the product of the concentrations of the constituent ions, each raised to the power that corresponds to the number of ions in one formula unit, 789 determination of K sp, 774–776 dissolving precipitates and, 787–789 fractional precipitation and, 781–784 simultaneous equilibria and, 784–786 solubility product constant, K sp and, 772–774 uses of K sp, 776–781 Solute The dispersed (dissolved) phase of a solution, 102, 110 and solutions in chemical reactions, 107–108 Solution A homogeneous mixture of two or more substances, 101–105, 110 See also Concentration adsorption phenomenon and, 535–536, 536t boiling point elevation and, 522–523, 522i, 523t in chemical reactions, 107–109 and colligative properties/dissociation of electrolytes, 526–529, 527i, 528t determination of volume in, 109 and dissolution of gases in liquids, 509–510 and dissolution of liquids in liquids (miscibility), 508, 508i, 509i and dissolution of solids in liquids, 505–508, 506i, 507t and effect of pressure on solubility, 513–514, 513i and effect of temperature on solubility, 511–513, 512i fractional distillation and, 520–522, 521i freezing point depression and, 523–525 freezing point depression/boiling point elevation and determination of molecular weight, 525–526 hydrophilic/hydrophobic, 536–540, 537i, 539i, 540i molality/mole fraction and, 514–515 osmotic pressure and, 530–533, 530i rates of dissolution/saturation and, 510–511, 511i and spontaneity of dissolution process, 503–505, 504i Solution Raoult’s Law and lowering of vapor pressure, 516–520, 516i, 519i Solution Tyndall effect and, 534–535, 536i, 536t Solvation The process by which solvent molecules surround and interact with solute ions or molecules, 505, 541 Solvent The dispersing medium of a solution, 102, 110, 503, 1002 environmentally friendly, 1040–1041 Solvolysis The reaction of a substance with the solvent in which it is dissolved, 726–727, 736 s orbital A spherically symmetrical atomic orbital; one per shell, 168 periodic table and, 165i quantum numbers and, 152, 154i sp2 hybrid orbitals, 298–299, 312, 318i sp3d hybrid orbitals, 302–308, 312 Space-filling molecular models, 50, 51i Specific gravity The ratio of the density of a substance to the density of water at the same temperature, 40 matter and, 31–34 Specific heat The amount of heat necessary to raise the temperature of a specific amount of a substance one degree Celsius with no change in state; usually expressed in J/g ? °C See Molar heat capacity, 37–39, 40, 463, 467t, 493 Specific rate constant, 615, 663 Spectator ions Ions in solution that not participate in a chemical reaction, 243, 367, 388 Spectral color The color associated with the wavelengths of light that are absorbed, 926–928, 926t, 929 Spectral line Any of a number of lines corresponding to definite wavelengths in an atomic emission or absorption spectrum; these lines represent the energy difference between two energy levels, 168 Spectrochemical series An arrangement of ligands in order of increasing ligand field strength, 927, 929 Spectrum Display of component wavelengths of electromagnetic radiation, 168 Speed of light, A11 Spherically symmetrical, 154 sp hybrid orbitals, 296–297 Spinnerets, 1024i Spin quantum number (ms) The quantum mechanical solution to a wave equation that indicates the relative spins of electrons (“spin up” and “spin down”), 152, 168 Spontaneous change See Product-favored change voltaic cells and, 795 Square planar A term used to describe molecules and polyatomic ions that have one atom in the center and four atoms at the corners of a square, 315, 322 Square planar complex A complex in which the metal atom or ion is in the center of a I-21 square plane, with a ligand donor atom at each of the four corners, 914–915, 929 Square pyramidal A term used to describe the molecular geometry of a molecule or polyatomic ion that has five atoms bonded to a central atom and one lone pair on the central atom (AB5U), 315, 322 Standard cell A cell in which all reactants and products are in their thermodynamic standard states (1 M for solution species and atm partial pressure for gases), 803, 833 Standard cell potential The potential difference, E cell , between standard reduction and oxidation half-cells, 833 Standard electrochemical conditions M concentration for solution species, atm partial pressure for gases, and pure solids and liquids, 833 Standard electrode A half-cell in which the oxidized and reduced forms of a species are present at unit activity: M solutions of dissolved species, atm partial pressure of gases, and pure solids and liquids, 833 Standard electrode potential By convention, the potential (E 0) of a half-reaction as a reduction relative to the standard hydrogen electrode, when all species are present at unit activity, 811–812, 813t, 833, A20–A22 copper–SHE cell and, 810–811, 811i corrosion and, 816–817, 817i corrosion protection and, 817–819, 818i half-reactions and, 814–816, 815t standard hydrogen electrode and, 808–809, 808i uses of, 812–814 zinc–SHE cell and, 809–810, 810i Standard enthalpy change, ∆H The enthalpy change in which the number of moles of reactants specified in the balanced chemical equation, all at standard states, is converted completely to the specified number of moles of products, all at standard states, 559, 595 Standard entropy change, ∆S The entropy change in which the number of moles of reactants specified in the balanced chemical equation, all at standard states, is converted completely to the specified number of moles of products, all at standard states, 580–586, 580i, 595, A23–A25 Standard entropy change, ∆S Second Law of Thermodynamics, 586–588 Standard hydrogen electrode (SHE) An electrode consisting of a platinum electrode that is immersed in a M H1 solution and that has H2 gas bubbled over it at atm pressure; defined as the reference electrode, with a potential of exactly 0.0000 volts, 808, 808–809, 808i, 833 copper–SHE cell and, 810–811, 811i zinc–SHE cell and, 809–810, 810i Standardization The process by which the concentration of a solution is accurately determined by titrating it against an accurately known amount of a primary standard, 380, 392 www.elsolucionario.net GLOSSARY/INDEX www.elsolucionario.net GLOSSARY/INDEX Standard molar enthalpy of formation, ∆H 0f (of a substance) The enthalpy change for the formation of one mole of a substance in a specified state from its elements in their standard states; also called standard molar heat of formation or just heat of formation, 559–560, 560t, 595, A23–A25 Standard molar entropy, S (of a substance) The absolute entropy of a substance in its standard state at 298 K, 580–586, 596 Standard molar heat of formation, 559–560, 560t See Standard molar enthalpy of formation, ∆H 0f (of a substance) Standard molar volume The volume occupied by one mole of an ideal gas under standard conditions, 22.414 liters, 413–414, 414t, 439 Standard reaction A reaction in which the numbers of moles of reactants shown in the balanced equation, all in their standard states, are completely converted to the numbers of moles of products shown in the balanced equation, also all at their standard states, 589–591, 596 Standard solution A solution of accurately known concentration, 392 Standard state (of a substance) See Thermodynamic standard state of a system Standard temperature and pressure (STP) Standard temperature 0°C (273.15 K), and standard pressure, one atmosphere, are standard conditions for gases, 411, 414, 414t, 416, 439 Standing wave, 150–151 State function A variable that defines the state of a system; a function that is independent of the pathway by which a process occurs, 552–553, 596 Statue of Liberty, 233 Stearic acid, 1005t Steel Iron alloyed with other metals, such as Mn, Cr, Ni, W, Mo, and V, and sometimes with C and Si, 852, 852t, 855 Stereochemistry The study of the threedimensional aspects of molecular structures, 1064 Stereoisomers Isomers in which the atoms are linked together in the same atom-to-atom order, but with different arrangements in space, 929, 1037–1041, 1038i, 1039i, 1064 See also Geometric isomerism; Optical isomers geometric (cis–trans) isomers, 919–921, 920i optical isomers, 921–922, 921i, 922i Steric effects of ligands, 915 Steroid molecules, 1002 Stoichiometry Description of the quantitative relationships among elements and compounds as they undergo chemical changes, 49, 79, 110 and solutions in chemical reactions, 108–109 Stoney, George, 121 Strong acid An acid that ionizes (separates into ions) completely, or very nearly completely, in dilute aqueous solution, 213–215, 214t, 243, 704–705, 704t See also Acid aqueous solutions and, 352, 359–360 and strong acid/strong base titration curves, 759–762 Strong base Metal hydroxide that is soluble in water and dissociates completely in dilute aqueous solution, 213, 215–216, 216t, 243 704–705, 704t See also Base aqueous solutions and, 352, 359–360 and strong acid/strong base titration curves, 759–762 and weak acid/strong base titration curves, 762–764, 763i, 763t Strong electrolyte A substance that conducts electricity well in dilute aqueous solution, 212–213, 243, 367, 387–388, 704–705, 704t, 736 Strong field ligand A ligand that exerts a strong crystal or ligand electric field and generally forms low spin complexes with metal ions when possible A ligand that forms a strong, 925, 927, 929 Strontium as Group 2A metal, 868 Structural (constitutional) isomers, 1036 See also Constitutional isomers (Applied to coordination compounds.) Isomers whose differences involve more than a single coordination sphere or else different donor atoms; they include ionization isomers, hydrate isomers, coordination isomers, and linkage isomers, 929 coordination isomers, 919 hydrate isomers, 919 ionization (ion–ion exchange) isomers, 918–919 linkage isomers, 919–920 Structural formula A representation that shows how atoms are connected in a compound, 79 Structural isomers See Constitutional isomers Strychnine, 1003 Sublimation The direct vaporization of a solid by heating without passing through the liquid state, 470, 470i, 493 Substance Any kind of matter all specimens of which have the same chemical composition and physical properties, 11t, 14i, 40 matter and, 13–19 Substitution reaction A reaction in which an atom or a group of atoms attached to a carbon atom is replaced by another atom or group of atoms No change occurs in the degree of saturation at the reactive carbon, 1014–1017, 1026 Substrate A reactant in an enzyme-catalyzed reaction, 651 Sulfur, 891–892 combustion reaction and, 204–205 occurence/use/properties of, 888–889, 888t, 889i oxides of, 890–891 oxoacids of, 892–893 in oxygen, 201i Supercritical fluid A substance at a temperature above its critical temperature A supercritical fluid cannot be described as either a liquid or gas, but has the properties of both, 472, 493 Superoxide A compound containing the superoxide ion, O22 (oxygen in the 212 oxidation state), 198–199, 206 Supersaturated solution A (metastable) solution that contains a higher-thansaturation concentration of solute; slight disturbance or seeding causes crystallization of excess solute, 511, 541 Surface tension The result of inward intermolecular forces of attraction among liquid particles that must be overcome to expand the surface area, 467t, 493 liquid state of matter and, 458–459, 459i Surfactant A “surface-active agent”; a substance that has the ability to emulsify and wash away oil and grease in an aqueous suspension, 542 Surroundings Everything in the environment of the system, 596 Symbol (of an element) A letter or group of letters that represents (identifies) an element, 17–18, 18i, 40 System The substances of interest in a process; the part of the universe under investigation, 596 t2g orbitals A set of dxy, dyz, and dxz orbitals in an octahedral complex; those d orbitals within a set with lobes bisecting (midway between) the x, y, and z axes, 924–926, 924i, 929 Tartaric acid, 1008t Tellurium occurence/use/properties of, 889 Temperature A measure of the intensity of heat, 34i, 35i, 40 Arrhenius equation and, 638–642, 639i average kinetic energy and, 428 Boyle’s Law and, 406–409, 407i conversions, 35–36 critical, 472 dependence of spontaneity on, 591–595, 593i, 593t equilibrium constant, K and, 692–693 LeChatelier’s Principle and, 677–678 nonideal gas behavior and, 435 solubility and, 511–513, 512i standard entropy change, ∆S and, 582, 582i standard temperature and pressure (STP), 411 thermodynamic standard state of a system and, 558 van der Waals equation and, 437 and vapor pressure of water, 425–426, 425t Ternary acid An acid containing three elements: H, O, and (usually) another nonmetal, 201–202, 206, 222–224, 223t, 246, 367, 1016 aqueous solution and, 357–359 formation of, 366 Ternary compound A compound that contains three different elements, 243, 367 Ternary salt A salt resulting from replacing the hydrogen in a ternary acid with another ion, 244 Tertiary alcohol An alcohol with three R groups bonded to the carbon bearing the i OH group, 997, 1026 www.elsolucionario.net I-22 www.elsolucionario.net Tertiary amine An amine in which three H atoms of ammonia have been replaced by organic groups, 1003, 1026 Tetrahedral A term used to describe the electronic geometry around a central atom that has four electron groups Also used to describe the molecular geometry of a molecule or polyatomic ion that has one atom in the center bonded to four atoms at the corners of a tetrahedron (AB4), 322 Tetrahedral electronic geometry AB2U2 species, 308–310, 316–317t AB3U species, 304–308, 316–317t AB4 species, 299–304, 316–317t ABU3 species, 310, 316–317t Tetrahedron (regular) A polyhedron with four equal-sized, equilateral triangular faces and four apices (corners), 322 Theoretical yield The maximum amount of a specified product that could be obtained from specified amounts of reactants, assuming complete consumption of the limiting reactant according to only one reaction and complete recovery of the product Compare with Actual yield, 110 Theory of Relativity, 938 Thermal equilibrium, 37, 37i Thermal pollution Introduction of heated waste water into natural waters, 513, 542 Thermochemical equation A balanced chemical equation together with a designation of the corresponding value of ∆Hrxn Sometimes used with changes in other thermodynamic quantities, 555–558, 596 Thermochemistry The observation, measurement, and prediction of energy changes for both physical changes and chemical reactions, 549, 596 bond energies and, 565–568, 566t, 567i calorimetry and, 553–555 ∆H/∆E relationship and, 574–575 enthalpy changes and, 553 First Law of Thermodynamics and, 550–551, 551i Hess’s Law and, 561–565, 564i internal energy changes, ∆E and, 568–573, 569i standard molar enthalpy of formation, ∆H 0f and, 559–560, 560t standard states/standard enthalpy changes and, 558–559 thermochemical equations and, 555–558 thermodynamic state of a system and, 552–553 Thermodynamically favorable (spontaneous) reaction A reaction that occurs with a net release of free energy, ∆G; a reaction for which ∆G is negative (see Section 15-16), 651 Thermodynamic equilibrium constant The equilibrium constant defined in terms of activities of the products and reactants, 689–692, 690i, 694 van’t Hoff factor, i and, 693 Thermodynamics The study of the energy transfers accompanying physical and chemical processes, 549, 596 constants for, A23–A25 First Law of, 550–551 Second Law of, 586–587 Third Law of, 580, 596 Thermodynamic standard state of a system The most stable state of the substance at one atmosphere pressure and at some specific temperature (25°C unless otherwise specified), 558–559, 596 Thermodynamic state of a system A set of conditions that completely specifies all of the properties of the system, 552–553, 596 Thermonuclear energy 963–964 Thermonuclear energy Energy from nuclear fusion reactions, 965 Third Law of Thermodynamics The entropy of a hypothetical pure, perfect, crystalline substance at absolute zero temperature is zero, 580, 596 Thompson, William, 409 Thomson, J J., 121, 123–124 Three Mile Island, 233, 959 Thymine, 1062–1063, 1063i Titration A procedure in which one solution is added to another solution until the chemical reaction between the two solutes is complete; usually the concentration of one solution is known and that of the other is unknown, 379, 392, 380i, 383i, 766 See also Acid–base titration acid–base indicators and, 757–758 aqueous acid–base reactions and, 379–385 buffering action and, 750–753 common ion effect/buffer solutions and, 744–750 preparation of, 753–757 and strong acid/strong base titration curves, 759–762 and summary of acid–base calculations, 765t and weak acid/strong base titration curves, 762–764 and weak acid/weak base titration curves, 764 Titration curve (for acid–base titration) A plot of pH versus volume of acid or base solution added, 759–762, 759t, 760i, 761i, 761t, 766 Toluene, 992t, 993i, 1016 Torr A unit of pressure; the pressure that will support a column of mercury mm high at 0°C, 403, 403i, 439, 462t Torricelli, Evangelista, 402–403 Total ionic equation An equation for a chemical reaction written to show the predominant form of all species in aqueous solution or in contact with water, 218–219, 244, 367 Trace elements, 862–863 trans fat, 1012 Transition state A relatively high-energy state in which bonds in reactant molecules are partially broken and new ones are partially formed, 651 Transition state theory A theory of reaction rates that states that reactants pass through high-energy transition states before forming products, 633–635, 634i, 635i, 651 Transuranium elements The elements with atomic numbers greater than 92 (uranium); none occur naturally and all must be prepared by nuclear I-23 bombardment of other elements, 943, 956–957, 965 Trigonal bipyramidal A term used to describe the electronic geometry around a central atom that has five electron groups Also used to describe the molecular geometry of a molecule or polyatomic ion that has one atom in the center bonded to five atoms at the corners of a trigonal bipyramid (AB5), 311, 322 Trigonal bipyramidal electronic geometry (AB5, AB4U, AB3U2, AB2U3 species), 310–313, 319t Trigonal planar (also plane triangular) A term used to describe the electronic geometry around a central atom that has three electron groups Also used to describe the molecular geometry of a molecule or polyatomic ion that has one atom in the center bonded to three atoms at the corners of an equilateral triangle (AB3), 322 Trigonal planar electronic geometry (AB3 species), 297–299, 316–317t Trigonal pyramidal A term used to describe the molecular geometry of a molecule or polyatomic ion that has three atoms bonded to a central atom and one lone pair on the central atom (AB3U), 305, 322 Trimethylamine, 720–721 Triple bond A covalent bond resulting from the sharing of six electrons (three pairs) between two atoms, 260–261, 280 compounds containing, 319–320 Triple point The point on a phase diagram that corresponds to the only pressure and temperature at which three phases (usually solid, liquid, and gas) of a substance can coexist at equilibrium, 472, 493 Trisaccharide A molecule consisting of three monosaccharides joined together by glycosidic bonds, 1055, 1064 T-shaped A term used to describe the molecular geometry of a molecule or polyatomic ion that has three atoms bonded to a central atom and two lone pairs on the central atom (AB3U2), 322 Tufa towers, 502 Tyndall effect The scattering of light by colloidal particles, 534–535, 536i, 536t, 542 Unambiguous stem, 220 Uncertainty, 23 Unit cell The smallest repeating unit showing all the structural characteristics of a crystal, 476, 476i, 477t, 478i, 493 Unit factor A factor in which the numerator and denominator are expressed in different units but represent the same or equivalent amounts Multiplying by a unit factor is the same as multiplying by one, 40 molarity and, 108 Unit factor method (dimensional analysis) matter and, 27–31 Units of measurement matter and, 19–22 www.elsolucionario.net GLOSSARY/INDEX www.elsolucionario.net GLOSSARY/INDEX Universal gas constant, 415 R, the proportionality constant in the ideal gas equation, PV nRT, 439 Universal indicators, 710, 711i, 758, 758i Universe The system plus the surroundings, 586, 596 Unsaturated hydrocarbons Hydrocarbons that contain double or triple carbon– carbon bonds, 973, 973i, 1026 Unshared pair See Lone pair Uracil, 1062–1063, 1063i Uranium decay series and, 948, 948i nuclear fission reactors and, 958–961 Uranium–lead dating, 950–951 U.S National Institute of Standards and Technology (NIST), 11 Valence bond (VB) theory Assumes that covalent bonds are formed when atomic orbitals on different atoms overlap and electrons are shared, 260, 288, 294, 294t, 322 linear electronic geometry (AB2 species) and, 296–297 molecular orbital theories and, 330 tetrahedral electronic geometry (AB2U2 species) and, 309–310 tetrahedral electronic geometry (AB3U species) and, 307–308 tetrahedral electronic geometry (AB4 species) and, 302–304 trigonal bipyramidal electronic geometry (AB5, AB4U, AB3U2, AB2U3 species) and, 310–315 trigonal planar electronic geometry (AB3 species) and, 298–299 Valence electrons The electrons in the outermost shell of an atom, 252, 280 Valence shell The outermost occupied electron shell of an atom, 288, 322 Valence shell electron pair repulsion (VSEPR) theory Assumes that valence electron pairs are arranged around the central element of a molecule or polyatomic ion so that there is maximum separation (and minimum repulsion) among electron groups, 288, 290–292, 322 linear electronic geometry (AB2 species) and, 295–296 tetrahedral electronic geometry (AB2U2 species) and, 309–310 tetrahedral electronic geometry (AB3U species) and, 305–307 tetrahedral electronic geometry (AB4 species) and, 300–302 trigonal bipyramidal electronic geometry (AB5, AB4U, AB3U2, AB2U3 species) and, 310–314 trigonal planar electronic geometry (AB3 species) and, 298 van der Waals, Johannes, 435 van der Waals equation An equation of state that extends the ideal gas law to real gases by inclusion of two empirically determined parameters, which are different for different gases, 437, 437t, 439 van’t Hoff factor, i A number that indicates the extent of dissociation or ionization of a solute; equal to the actual colligative property divided by the colligative property calculated assuming no ionization or dissociation, 542, 527–529, 527t, 692–693, 694 van Vleck, J H., 924 Vapor A gas formed by boiling or evaporation of a liquid or sublimation of a solid; a term commonly used when some of the liquid or solid remains in contact with the gas, 401–402, 439 Vaporization See Evaporation Vapor pressure The partial pressure of a vapor in equilibrium with its parent liquid or solid, 425–426, 425t, 439, 467t, 493 liquid state of matter and, 461–462, 462i, 462t Vapor pressure Raoult’s Law and lowering of, 516–520, 516i, 519i Viscosity The tendency of a liquid to resist flow; the inverse of its fluidity, 467t, 493 liquid state of matter and, 457–458, 458i Volatile acids, 365 Volatility The ease with which a liquid vaporizes, 493 Volta, Alessandro, 803 Voltage Potential difference between two electrodes; a measure of the chemical potential for a redox reaction to occur, 833 Voltaic cell An electrochemical cell in which a spontaneous (product-favored) chemical reaction produces electricity; also called a galvanic cell, 795, 803, 833 construction of simple, 803 copper–silver cell and, 806–808, 807i primary, 828–829, 828i secondary, 829–832, 830i, 832i zinc–copper cell and, 804–806 Voltaic cell Zinc–Copper cell and, 805i Volume, 21, 21t, 24i, 30 ∆H/∆E relationship and, 574–575 internal energy changes, ∆E and, 570–571, 571i mass relationship with, 426–428 metallic bonding and, 483 standard entropy change, ∆S and, 583, 583i van der Waals equation and, 437 Volume LeChatelier’s Principle and, 675–676 Von Laue, Max, 474 VSEPR See Valence shell electron pair repulsion (VSEPR) theory Vulcanization The process in which sulfur is added to rubber and heated to 140°C to cross-link the linear rubber polymer into a three-dimensional polymer, 1021, 1026 reactions of nonmetal oxides with, 201–202 simplest/molecular formulas for, 63–64 as solvent, 104 Water purification and hemodialysis, 534–535 Wavelength (l) The distance between two identical points of a wave, 138–142, 139i, 168 spectrochemical series and, 926–928, 926t Wavelength (l) Planck equation and, 147–148 Waxes, 1011 Weak acid An acid that ionizes only slightly in dilute aqueous solution, 214–215, 214t, 244 See also Acid aqueous solutions and, 352, 359–360 carboxyl groups and, 1004 ionization constant for, 710–723, 710i, 711i, 711t and weak acid/strong base titration curves, 762–764, 763i, 763t and weak acid/weak base titration curves, 764 Weak base A molecular substance that ionizes only slightly in water to produce an alkaline (base) solution, 216, 244 See also Base aqueous solutions and, 352, 359–360 ionization constant for, 710–723, 710i, 711i, 711t and weak acid/weak base titration curves, 764 Weak electrolyte A substance that conducts electricity poorly, 212, 244, 367 colligative properties (of solutions) and, 528–529 Weak field ligand A ligand that exerts a weak crystal or ligand field and generally forms high spin complexes with metals A ligand that forms a weak dative bond, 925, 929 Weight A measure of the gravitational attraction of the earth for a body, 40 Werner, Alfred, 910 Wideroe, Rolf, 954 Wine selection with dinner, 540 Wöhler, Friedrich, 971 Work The application of a force through a distance; for physical changes or chemical reactions at constant external pressure, the work done on the system is 2P DV; for chemical reactions that involve gases, the work done on the system can be expressed as −(∆n)RT, 568–573, 596 Wright, Joseph, 180 Water as acid or base, 350–354 autoionization of, 705–706, 705t gas collected over, 425–426 gas-formation reactions and, 240 physical/chemical properties of, 12i physical properties of, 12t Zinc–copper cell, 804–806, 805i Zinc–SHE cell, 809–810, 810i Zone refining A method of purifying a bar of metal by passing it through an induction heater; this causes impurities to move along in the melted portion, 846, 855 Xenon, 881–882, 881t–882t X-ray diffraction, 474, 474i, 476i X-ray fluorescence spectroscopy, 125–126 Xylene, 991, 992t Yucca Mountain, 962–963 www.elsolucionario.net I-24 ... 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