Chemistry the central science 13e by theodore l brown 2

Chemistry the central science 13e by theodore l brown 2 Chemistry the central science 13e by theodore l brown 2 Chemistry the central science 13e by theodore l brown 2 Chemistry the central science 13e by theodore l brown 2 Chemistry the central science 13e by theodore l brown 2 Chemistry the central science 13e by theodore l brown 2 Chemistry the central science 13e by theodore l brown 2

662 chapter 15 Chemical Equilibrium are shown here Which reaction has a larger equilibrium constant? [Sections 15.1 and 15.2] t = 10 s 20 s 30 s A(g) + B(g) t = 10 s 20 s 30 s X(g) + Y(g) 40 s 50 s AB(g) 40 s 50 s XY(g) 15.6 Ethene 1C2H42 reacts with halogens 1X22 by the following reaction: C2H41g2 + X21g2 ∆ C2H4X21g2 The following figures represent the concentrations at equilibrium at the same temperature when X2 is Cl2 (green), Br2 (brown), and I2 (purple) List the equilibria from smallest to largest equilibrium constant [Section 15.3] 5.0 g PbO2(g) in both vessels Vessel A V = 50 mL 15.8 The reaction A2 + B2 ∆ AB has an equilibrium constant Kc = 1.5 The following diagrams represent reaction mixtures containing A2 molecules (red), B2 molecules (blue), and AB molecules (a) Which reaction mixture is at equilibrium? (b) For those mixtures that are not at equilibrium, how will the reaction proceed to reach equilibrium? [Sections 15.5 and 15.6] (i) (a) (b) Vessel B V = 100 mL (ii) (iii) 15.9 The reaction A21g2 + B1g2 ∆ A1g2 + AB1g2 has an equilibrium constant of Kp = The accompanying diagram shows a mixture containing A atoms (red), A2 molecules, and AB molecules (red and blue) How many B atoms should be added to the diagram to illustrate an equilibrium mixture? [Section 15.6] (c) 15.7 When lead (IV) oxide is heated above 300 °C it decomposes according to the following reaction PbO21s2 ∆ PbO1s2 + O21g2 Consider the two sealed vessels of PbO2 shown here If both vessels are heated to 400 °C and allowed to come to equilibitum which of the following statements is true? (a) There will be less PbO2 remaining in vessel A, (b) There will be less PbO2 remaining in vessel B, (c) The amount of PbO2 remaining in each vessel will be the same [Section 15.4] 15.10 The diagram shown here represents the equilibrium state for the reaction A21g2 + B1g2 ∆ 2AB1g2 (a) Assuming the volume is L, calculate the equilibrium constant Kc for the reaction (b) If the volume of the equilibrium mixture is decreased, will the number of AB molecules increase or decrease? [Sections 15.5 and 15.7] Exercises 663 15.15 Write the expression for Kc for the following reactions In each case indicate whether the reaction is homogeneous or heterogeneous (a) NO1g2 ∆ N2O1g2 + NO21g2 (b) CH41g2 + H2S1g2 ∆ CS21g2 + H21g2 (c) Ni1CO241g2 ∆ Ni1s2 + CO1g2 (d) HF1aq2 ∆ H+1aq2 + F-1aq2 (e) Ag1s2 + Zn2+1aq2 ∆ Ag +1aq2 + Zn1s2 (f) H2O1l2 ∆ H+1aq2 + OH-1aq2 (g) H2O1l2 ∆ H+1aq2 + OH-1aq2 15.11 The following diagrams represent equilibrium mixtures for the reaction A2 + B ∆ A + AB at 300 K and 500 K The A atoms are red, and the B atoms are blue Is the reaction exothermic or endothermic? [Section 15.7] 15.16 Write the expressions for Kc for the following reactions In each case indicate whether the reaction is homogeneous or heterogeneous (a) O31g2 ∆ O21g2 (b) Ti1s2 + Cl21g2 ∆ TiCl41l2 (c) C2H41g2 + H2O1g2 ∆ C2H61g2 + O21g2 (d) C1s2 + H21g2 ∆ CH41g2 (e) HCl1aq2 + O21g2 ∆ H2O1l2 + Cl21g2 (f) C8H181l2 + 25 O21g2 ∆ 16 CO21g2 + 18 H2O1g2 (g) C8H181l2 + 25 O21g2 ∆ 16 CO21g2 + 18 H2O1l2 15.17 When the following reactions come to equilibrium, does the equilibrium mixture contain mostly reactants or mostly products? 300 K 500 K [AB] 15.12 The following graph represents the yield of the compound AB at equilibrium in the reaction A1g2 + B1g2 ¡ AB1g2 at two different pressures, x and y, as a function of temperature P=y P=x Temperature (a) Is this reaction exothermic or endothermic? (b) Is P = x greater or smaller than P = y? [Section 15.7] Equilibrium; The Equilibrium Constant (Sections 15.1–15.4) 15.13 Suppose that the gas-phase reactions A ¡ B and B ¡ A are both elementary processes with rate constants of 4.7 * 10-3 s-1 and 5.8 * 10-1 s-1, respectively (a) What is the value of the equilibrium constant for the equilibrium A1g2 ∆ B1g2? (b) Which is greater at equilibrium, the partial pressure of A or the partial pressure of B? 15.14 Consider the reaction A + B ∆ C + D Assume that both the forward reaction and the reverse reaction are elementary processes and that the value of the equilibrium constant is very large (a) Which species predominate at equilibrium, reactants or products? (b) Which reaction has the larger rate constant, the forward or the reverse? (a) N21g2 + O21g2 ∆ NO1g2; Kc = 1.5 * 10-10 (b) SO21g2 + O21g2 ∆ SO31g2; Kp = 2.5 * 109 15.18 Which of the following reactions lies to the right, favoring the formation of products, and which lies to the left, favoring formation of reactants? (a) NO1g2 + O21g2 ∆ NO21g2; Kp = 5.0 * 1012 (b) HBr1g2 ∆ H21g2 + Br21g2; Kc = 5.8 * 10-18 15.19 Which of the following statements are true and which are false? (a) The equilibrium constant can never be a negative number (b) In reactions that we draw with a single-headed arrow, the equilibrium constant has a value that is very close to zero (c) As the value of the equilibrium constant increases the speed at which a reaction reaches equilibrium increases 15.20 Which of the following statements are true and which are false? (a) For the reaction A1g2 + B1g2 ∆ A2B1g2 Kc and Kp are numerically the same (b) It is possible to distinguish Kc from Kp by comparing the units used to express the equilibrium constant (c) For the equilibrium in (a), the value of Kc increases with increasing pressure 15.21 If Kc = 0.042 for PCl31g2 + Cl21g2 ∆ PCl51g2 at 500 K, what is the value of Kp for this reaction at this temperature? 15.22 Calculate Kc at 303 K for SO21g2 + Cl21g2 ∆ SO2Cl21g2 if Kp = 34.5 at this temperature 15.23 The equilibrium constant for the reaction NO1g2 + Br21g2 ∆ NOBr1g2 is Kc = 1.3 * 10-2 at 1000 K (a) At this temperature does the equilibrium favor NO and Br2, or does it favor NOBr? (b) Calculate Kc for NOBr1g2 ∆ NO1g2 + Br21g2 (c) Calculate Kc for NOBr1g2 ¡ NO1g2 + 12 Br21g2 15.24 Consider the following equilibrium: H21g2 + S21g2 ∆ H2S1g2 Kc = 1.08 * 107at 700 °C 664 chapter 15 Chemical Equilibrium (a) Calculate Kp (b) Does the equilibrium mixture contain mostly H2 and S2 or mostly H2S? (c) Calculate the value of Kc if you rewrote the equation H21g2 + 12 S21g2 ∆ H2S1g2 15.25 At 1000 K, Kp = 1.85 for the reaction SO21g2 + O21g2 ∆ SO31g2 (a) What is the value of Kp for the reaction SO31g2 ∆ SO21g2 + 12 O21g2? (b) What is the value of Kp for the reaction SO21g2 + O21g2 ∆ SO31g2? (c) What is the value of Kc for the reaction in part (b)? 15.26 Consider the following equilibrium, for which Kp = 0.0752 at 480 °C: Cl21g2 + H2O1g2 ∆ HCl1g2 + O21g2 (a) What is the value of Kp for the reaction HCl1g2 + O21g2 ∆ Cl21g2 + H2O1g2? (b) What is the value of Kp for the reaction Cl21g2 + H2O1g2 ∆ HCl1g2 + 12 O21g2? (c) What is the value of Kc for the reaction in part (b)? 15.27 The following equilibria were attained at 823 K: CoO1s2 + H21g2 ∆ Co1s2 + H2O1g2 Kc = 67 CoO1s2 + CO1g2 ∆ Co1s2 + CO21g2 Kc = 490 Based on these equilibria, calculate the equilibrium constant for H21g2 + CO21g2 ∆ CO1g2 + H2O1g2 at 823 K 15.28 Consider the equilibrium N21g2 + O21g2 + Br21g2 ∆ NOBr1g2 Calculate the equilibrium constant Kp for this reaction, given the following information (at 298 K): NO1g2 + Br21g2 ∆ NOBr1g2 Kc = 2.0 NO1g2 ∆ N21g2 + O21g2 Kc = 2.1 * 1030 15.29 Mercury(I) oxide decomposes into elemental mercury and e l e m e n t a l o x y g e n : Hg2O1s2 ∆ Hg1l2 + O21g2 (a) Write the equilibrium-constant expression for this reaction in terms of partial pressures (b) Suppose you run this reaction in a solvent that dissolves elemental mercury and elemental oxygen Rewrite the equilibrium-constant expression in terms of molarities for the reaction, using (solv) to indicate solvation 15.30 Consider the equilibrium Na2O1s2 + SO21g2 ∆ Na2SO31s2 (a) Write the equilibrium-constant expression for this reaction in terms of partial pressures (b) All the compounds in this reaction are soluble in water Rewrite the equilibriumconstant expression in terms of molarities for the aqueous reaction Calculating Equilibrium Constants (Section 15.5) 15.31 Methanol 1CH3OH2 is produced commercially by the catalyzed reaction of carbon monoxide and hydrogen: CO1g2 + H21g2 ∆ CH3OH1g2 A n e q u i l i b r i u m mixture in a 2.00-L vessel is found to contain 0.0406 mol CH3OH, 0.170 mol CO, and 0.302 mol H2 at 500 K Calculate Kc at this temperature 15.32 Gaseous hydrogen iodide is placed in a closed container at 425 °C, where it partially decomposes to hydrogen and iodine: HI1g2 ∆ H21g2 + I21g2 At equilibrium it is found that 3HI4 = 3.53 * 10-3 M, 3H24 = 4.79 * 10-4 M, and 3I24 = 4.79 * 10-4 M What is the value of Kc at this temperature? 15.33 The equilibrium NO1g2 + Cl21g2 ∆ NOCl1g2 is established at 500 K An equilibrium mixture of the three gases has partial pressures of 0.095 atm, 0.171 atm, and 0.28 atm for NO, Cl2, and NOCl, respectively (a) Calculate Kp for this reaction at 500.0 K (b) If the vessel has a volume of 5.00 L, calculate Kc at this temperature 15.34 Phosphorus trichloride gas and chlorine gas react to form phosphorus pentachloride gas: PCl31g2 + Cl21g2 ∆ PCl51g2 A 7.5-L gas vessel is charged with a mixture of PCl31g2 and Cl21g2, which is allowed to equilibrate at 450 K At equilibrium the partial pressures of the three gases are PPCl3 = 0.124 atm, PCl2 = 0.157 atm, a n d PPCl5 = 1.30 atm (a) What is the value of Kp at this temperature? (b) Does the equilibrium favor reactants or products? (c) Calculate Kc for this reaction at 450 K 15.35 A mixture of 0.10 mol of NO, 0.050 mol of H2, and 0.10 mol of H2O is placed in a 1.0-L vessel at 300 K The following equilibrium is established: NO1g2 + H21g2 ∆ N21g2 + H2O1g2 At equilibrium 3NO4 = 0.062 M (a) Calculate the equilibrium concentrations of H2, N2, and H2O (b) Calculate Kc 15.36 A mixture of 1.374 g of H2 and 70.31 g of Br2 is heated in a 2.00-L vessel at 700 K These substances react according to H21g2 + Br21g2 ∆ HBr1g2 At equilibrium, the vessel is found to contain 0.566 g of H2 (a) Calculate the equilibrium concentrations of H2, Br2, and HBr (b) Calculate Kc 15.37 A mixture of 0.2000 mol of CO2, 0.1000 mol of H2, and 0.1600 mol of H2O is placed in a 2.000-L vessel The following equilibrium is established at 500 K: CO21g2 + H21g2 ∆ CO1g2 + H2O1g2 (a) Calculate the initial partial pressures of CO2, H2, and H2O (b) At equilibrium PH2O = 3.51 atm Calculate the equilibrium partial pressures of CO2, H2, and CO (c) Calculate Kp for the reaction (d) Calculate Kc for the reaction 15.38 A flask is charged with 1.500 atm of N2O41g2 and 1.00 atm NO21g2 at 25 °C, and the following equilibrium is achieved: N2O41g2 ∆ NO21g2 After equilibrium is reached, the partial pressure of NO2 is 0.512 atm (a) What is the equilibrium partial pressure of N2O4? (b) Calculate the value of Kp for the reaction (c) Calculate Kc for the reaction 15.39 Two different proteins X and Y are dissolved in aqueous solution at 37 °C The proteins bind in a 1:1 ratio to form XY A solution that is initially 1.00 mM in each protein is allowed to reach equilibrium At equilibrium, 0.20 mM of free X and 0.20 mM of free Y remain What is Kc for the reaction? 15.40 A chemist at a pharmaceutical company is measuring equilibrium constants for reactions in which drug candidate molecules bind to a protein involved in cancer The drug Exercises molecules bind the protein in a 1:1 ratio to form a drug– protein complex The protein concentration in aqueous solution at 25 °C is 1.50 * 10-6M Drug A is introduced into the protein solution at an initial concentration of 2.00 * 10-6M Drug B is introduced into a separate, identical protein solution at an initial concentration of 2.00 * 10-6M At equilibrium, the drug A-protein solution has an A-protein complex concentration of 1.00 * 10-6M, and the drug B solution has a B-protein complex concentration of 1.40 * 10-6M Calculate the Kc value for the A-protein binding reaction and for the Bprotein binding reaction Assuming that the drug that binds more strongly will be more effective, which drug is the better choice for further research? Applications of Equilibrium Constants (Section 15.6) 15.47 At 1285 °C, the equilibrium constant for the reaction Br21g2 ∆ Br1g2 is Kc = 1.04 * 10-3 A 0.200-L vessel containing an equilibrium mixture of the gases has 0.245 g Br21g2 in it What is the mass of Br1g2 in the vessel? 15.48 For the reaction H21g2 + I21g2 ∆ HI1g2, Kc = 55.3 at 700 K In a 2.00-L flask containing an equilibrium mixture of the three gases, there are 0.056 g H2 and 4.36 g I2 What is the mass of HI in the flask? 15.49 At 800 K, the equilibrium constant for I21g2 ∆ I1g2 is Kc = 3.1 * 10-5 If an equilibrium mixture in a 10.0-L vessel contains 2.67 * 10-2 g of I(g), how many grams of I2 are in the mixture? 15.50 For SO21g2 + O21g2 ∆ SO31g2, Kp = 3.0 * 104 at 700 K In a 2.00-L vessel, the equilibrium mixture contains 1.17 g of SO3 and 0.105 g of O2 How many grams of SO2 are in the vessel? 15.51 At 2000 °C, the equilibrium constant for the reaction 15.41 (a) If Qc Kc, in which direction will a reaction proceed in order to reach equilibrium? (b) What condition must be satisfied so that Qc = Kc? 15.42 (a) If Qc Kc, how must the reaction proceed to reach equilibrium? (b) At the start of a certain reaction, only reactants are present; no products have been formed What is the value of Qc at this point in the reaction? 15.43 At 100 °C, the equilibrium constant for the reaction COCl21g2 ∆ CO1g2 + Cl21g2 h a s t h e v a l u e Kc = 2.19 * 10-10 Are the following mixtures of COCl2, CO, and Cl2 at 100 °C at equilibrium? If not, indicate the direction that the reaction must proceed to achieve equilibrium (a) 3COCl24 = 2.00 * 10-3 M, 3CO4 = 3.3 * 10-6 M, 3Cl24 = 6.62 * 10-6 M (b) 3COCl24 = 4.50 * 10-2 M, 3CO4 = 1.1 * 10-7 M, 3Cl24 = 2.25 * 10-6 M -6 (c) 3COCl24 = 0.0100 M, 3CO4 = 3Cl24 = 1.48 * 10 M 15.44 As shown in Table 15.2, Kp for the equilibrium N21g2 + H21g2 ∆ NH31g2 is 4.51 * 10-5 at 450 °C For each of the mixtures listed here, indicate whether the mixture is at equilibrium at 450 °C If it is not at equilibrium, indicate the direction (toward product or toward reactants) in which the mixture must shift to achieve equilibrium (a) 98 atm NH3, 45 atm N2, 55 atm H2 (b) 57 atm NH3, 143 atm N2, no H2 (c) 13 atm NH3, 27 atm N2, 82 atm H2 15.45 At 100 °C, Kc = 0.078 for the reaction SO2Cl21g2 ∆ SO21g2 + Cl21g2 In an equilibrium mixture of the three gases, the concentrations of SO2Cl2 and SO2 are 0.108 M and 0.052 M, respectively What is the partial pressure of Cl2 in the equilibrium mixture? 15.46 At 900 K, the following reaction has Kp = 0.345: SO21g2 + O21g2 ∆ SO31g2 665 In an equilibrium mixture the partial pressures of SO2 and O2 are 0.135 atm and 0.455 atm, respectively What is the equilibrium partial pressure of SO3 in the mixture? NO1g2 ∆ N21g2 + O21g2 is Kc = 2.4 * 103 If the initial concentration of NO is 0.175 M, what are the equilibrium concentrations of NO, N2, and O2? 15.52 For the equilibrium Br21g2 + Cl21g2 ∆ BrCl1g2 at 400 K, Kc = 7.0 If 0.25 mol of Br2 and 0.55 mol of Cl2 are introduced into a 3.0-L container at 400 K, what will be the equilibrium concentrations of Br2, Cl2, and BrCl? 15.53 At 373 K, Kp = 0.416 for the equilibrium NOBr1g2 ∆ NO1g2 + Br21g2 If the pressures of NOBr(g) and NO(g) are equal, what is the equilibrium pressure of Br21g2? 15.54 At 218 °C, Kc = 1.2 * 10-4 for the equilibrium NH4SH1s2 ∆ NH31g2 + H2S1g2 Calculate the equilibrium concentrations of NH3 and H2S if a sample of solid NH4SH is placed in a closed vessel at 218 °C and decomposes until equilibrium is reached 15.55 Consider the reaction CaSO41s2 ∆ Ca2+1aq2 + SO42-1aq2 At 25 °C, the equilibrium constant is Kc = 2.4 * 10-5 for this reaction (a) If excess CaSO41s2 is mixed with water at 25 °C to produce a saturated solution of CaSO4, what are the equilibrium concentrations of Ca2+ and SO42-? (b) If the resulting solution has a volume of 1.4 L, what is the minimum mass of CaSO41s2 needed to achieve equilibrium? 15.56 At 80 °C, Kc = 1.87 * 10-3 for the reaction PH3BCl31s2 ∆ PH31g2 + BCl31g2 (a) Calculate the equilibrium concentrations of PH3 and BCl3 if a solid sample of PH3BCl3 is placed in a closed vessel at 80 °C and decomposes until equilibrium is reached (b) If the flask has a volume of 0.250 L, what is the minimum mass of PH3BCl31s2 that must be added to the flask to achieve equilibrium? 15.57 For the reaction I2 + Br21g2 ∆ IBr1g2, Kc = 280 at 150 °C Suppose that 0.500 mol IBr in a 2.00-L flask is allowed to reach equilibrium at 150 °C What are the equilibrium concentrations of IBr, I2, and Br2? 666 chapter 15 Chemical Equilibrium 15.58 At 25 °C, the reaction CaCrO41s2 ∆ Ca2+1aq2 + CrO42-1aq2 has an equilibrium constant Kc = 7.1 * 10-4 What are the equilibrium concentrations of Ca2 + and CrO42- in a saturated solution of CaCrO4? 15.59 Methane, CH4, reacts with I2 according to the reaction CH41g2 + l21g2 ∆ CH3l1g2 + HI1g2 At 630 K, Kp for this reaction is 2.26 * 10-4 A reaction was set up at 630 K with initial partial pressures of methane of 105.1 torr and of 7.96 torr for I2 Calculate the pressures, in torr, of all reactants and products at equilibrium 15.60 The reaction of an organic acid with an alcohol, in organic solvent, to produce an ester and water is commonly done in the pharmaceutical industry This reaction is catalyzed by strong acid (usually H2SO4) A simple example is the reaction of acetic acid with ethyl alcohol to produce ethyl acetate and water: CH3COOH1solv2 + CH3CH2OH1solv2 ∆ CH3COOCH2CH31solv2 + H2O1solv2 where “(solv)” indicates that all reactants and products are in solution but not an aqueous solution The equilibrium constant for this reaction at 55 °C is 6.68 A pharmaceutical chemist makes up 15.0 L of a solution that is initially 0.275 M in acetic acid and 3.85 M in ethanol At equilibrium, how many grams of ethyl acetate are formed? Le Châtelier’s Principle (Section 15.7) 15.61 Consider the following equilibrium for which ∆H SO21g2 + O21g2 ∆ SO31g2 How will each of the following changes affect an equilibrium mixture of the three gases: (a) O21g2 is added to the system; (b) the reaction mixture is heated; (c) the volume of the reaction vessel is doubled; (d) a catalyst is added to the mixture; (e) the total pressure of the system is increased by adding a noble gas; (f) SO31g2 is removed from the system? 15.62 Consider the reaction NH31g2 + O21g2 ∆ NO1g2 + H2O1g2, ∆H = - 904.4 kJ Does each of the following increase, decrease, or leave unchanged the yield of NO at equilibrium? (a) increase 3NH34; (b) increase 3H2O4; (c) decrease 3O24; (d) decrease the volume of the container in which the reaction occurs; (e) add a catalyst; (f) increase temperature 15.63 How the following changes affect the value of the equilibrium constant for a gas-phase exothermic reaction: (a) removal of a reactant, (b) removal of a product, (c) decrease in the ­volume, (d) decrease in the temperature, (e) addition of a catalyst? 15.64 For a certain gas-phase reaction, the fraction of products in an equilibrium mixture is increased by either increasing the temperature or by increasing the volume of the reaction vessel (a) Is the reaction exothermic or endothermic? (b) Does the balanced chemical equation have more molecules on the reactant side or product side? 15.65 Consider the following equilibrium between oxides of nitrogen NO1g2 ∆ NO21g2 + N2O1g2 (a) Use data in Appendix C to calculate ∆H° for this ­reaction (b) Will the equilibrium constant for the reaction increase or decrease with increasing temperature? (c) At constant temperature, would a change in the volume of the container affect the fraction of products in the equilibrium mixture? 15.66 Methanol 1CH3OH2 can be made by the reaction of CO with H2: CO1g2 + H21g2 ∆ CH3OH1g2 (a) Use thermochemical data in Appendix C to calculate ∆H° for this reaction (b) To maximize the equilibrium yield of methanol, would you use a high or low temperature? (c) To maximize the equilibrium yield of methanol, would you use a high or low pressure? 15.67 Ozone, O3, decomposes to molecular oxygen in the stratosphere according to the reaction O31g2 ¡ O21g2 Would an increase in pressure favor the formation of ozone or of oxygen? 15.68 The water–gas shift reaction CO1g2 + H2O1g2 ∆ CO21g2 + H21g2 is used industrially to produce hydrogen The reaction enthalpy is ∆H° = - 41 kJ (a) To increase the equilibrium yield of hydrogen would you use high or low temperature? (b) Could you increase the equilibrium yield of hydrogen by controlling the pressure of this reaction? If so would high or low pressure favor formation of H21g2? Additional Exercises 15.69 Both the forward reaction and the reverse reaction in the following equilibrium are believed to be elementary steps: CO1g2 + Cl21g2 ∆ COCl1g2 + Cl1g2 flask and is found to contain 8.62 g of CO, 2.60 g of H2, 43.0 g of CH4, and 48.4 g of H2O Assuming that equilibrium has been reached, calculate Kc and Kp for the reaction CH41g2 + H2O1g2 ∆ CO1g2 + H21g2 At 25 °C, the rate constants for the forward and reverse reactions are 1.4 * 10-28 M -1 s-1 and 9.3 * 1010 M -1 s-1, respectively (a) What is the value for the equilibrium constant at 25 °C? (b) Are reactants or products more plentiful at equilibrium? 15.72 When 2.00 mol of SO2Cl2 is placed in a 2.00-L flask at 303 K, 56% of the SO2Cl2 decomposes to SO2 and Cl2 : 15.70 If Kc = for the equilibrium A1g2 ∆ B1g2, what is the relationship between [A] and [B] at equilibrium? (a) Calculate Kc for this reaction at this temperature (b) Calculate Kp for this reaction at 303 K (c) According to Le Châtelier’s principle, would the percent of SO2Cl2 that decomposes increase, decrease or stay the same if the mixture 15.71 A mixture of CH4 and H2O is passed over a nickel catalyst at 1000 K The emerging gas is collected in a 5.00-L SO2Cl21g2 ∆ SO21g2 + Cl21g2 Additional Exercises were transferred to a 15.00-L vessel? (d) Use the equilibrium constant you calculated above to determine the percentage of SO2Cl2 that decomposes when 2.00 mol of SO2Cl2 is placed in a 15.00-L vessel at 303 K 15.73 A mixture of H2, S, and H2S is held in a 1.0-L vessel at 90 °C and reacts according to the equation: H21g2 + S1s2 ∆ H2S1g2 At equilibrium, the mixture contains 0.46 g of H2S and 0.40 g H2 (a) Write the equilibrium-constant expression for this reaction (b) What is the value of Kc for the reaction at this temperature? 15.74 A sample of nitrosyl bromide (NOBr) decomposes according to the equation NOBr1g2 ∆ NO1g2 + Br21g2 An equilibrium mixture in a 5.00-L vessel at 100 °C contains 3.22 g of NOBr, 3.08 g of NO, and 4.19 g of Br2 (a) Calculate Kc (b) What is the total pressure exerted by the mixture of gases? (c) What was the mass of the original sample of NOBr? 667 At 700 K, the equilibrium constant Kp for this reaction is 0.26 Predict the behavior of each of the following mixtures at this temperature and indicate whether or not the mixtures are at equilibrium If not, state whether the mixture will need to produce more products or reactants to reach equilibrium (a) PNO = 0.15 atm, PCl2 = 0.31 atm, PNOCl = 0.11 atm (b) PNO = 0.12 atm, PCl2 = 0.10 atm, PNOCl = 0.050 atm (c) PNO = 0.15 atm, PCl2 = 0.20 atm, PNOCl = 5.10 * 10-3 atm 15.82 At 900 °C, Kc = 0.0108 for the reaction CaCO31s2 ∆ CaO1s2 + CO21g2 A mixture of CaCO3, CaO, and CO2 is placed in a 10.0-L vessel at 900 °C For the following mixtures, will the amount of CaCO3 increase, decrease, or remain the same as the system approaches equilibrium? (a) 15.0 g CaCO3, 15.0 g CaO, and 4.25 g CO2 (b) 2.50 g CaCO3, 25.0 g CaO, and 5.66 g CO2 (c) 30.5 g CaCO3, 25.5 g CaO, and 6.48 g CO2 15.75 Consider the hypothetical reaction A1g2 ∆ B1g2 A flask is charged with 0.75 atm of pure A, after which it is allowed to reach equilibrium at °C At equilibrium, the partial pressure of A is 0.36 atm (a) What is the total pressure in the flask at equilibrium? (b) What is the value of Kp? (c) What could we to maximize the yield of B? 15.83 When 1.50 mol CO2 and 1.50 mol H2 are placed in a 3.00-L container at 395 °C, the following reaction occurs: CO21g2 + H21g2 ∆ CO1g2 + H2O1g2 If Kc = 0.802, what are the concentrations of each substance in the equilibrium mixture? 15.76 As shown in Table 15.2, the equilibrium constant for the reaction N21g2 + H21g2 ∆ NH31g2 is Kp = 4.34 * 10-3 at 300 °C Pure NH3 is placed in a 1.00-L flask and allowed to reach equilibrium at this temperature There are 1.05 g NH3 in the equilibrium mixture (a) What are the masses of N2 and H2 in the equilibrium mixture? (b) What was the initial mass of ammonia placed in the vessel? (c) What is the total pressure in the vessel? 15.84 The equilibrium constant Kc for C1s2 + CO21g2 ∆ CO1g2 is 1.9 at 1000 K and 0.133 at 298 K (a) If excess C is allowed to react with 25.0 g of CO2 in a 3.00-L vessel at 1000 K, how many grams of CO are produced? (b) How many grams of C are consumed? (c) If a smaller vessel is used for the reaction, will the yield of CO be greater or smaller? (d) Is the reaction endothermic or exothermic? 15.77 For the equilibrium 15.85 NiO is to be reduced to nickel metal in an industrial process by use of the reaction IBr1g2 ∆ I21g2 + Br21g2 Kp = 8.5 * 10-3 at 150 °C If 0.025 atm of IBr is placed in a 2.0-L container, what is the partial pressure of all substances after equilibrium is reached? 15.78 For the equilibrium PH3BCl31s2 ∆ PH31g2 + BCl31g2 Kp = 0.052 at 60 °C (a) Calculate Kc (b) After 3.00 g of solid PH3BCl3 is added to a closed 1.500-L vessel at 60 °C, the vessel is charged with 0.0500 g of BCl31g2 What is the equilibrium concentration of PH3? [15.79] Solid NH4SH is introduced into an evacuated flask at 24 °C The following reaction takes place: NH4SH1s2 ∆ NH31g2 + H2S1g2 At equilibrium, the total pressure (for NH3 and H2S taken together) is 0.614 atm What is Kp for this equilibrium at 24 °C? [15.80] A 0.831-g sample of SO3 is placed in a 1.00-L container and heated to 1100 K The SO3 decomposes to SO2 and O2: SO31g2 ∆ SO21g2 + O21g2 At equilibrium, the total pressure in the container is 1.300 atm Find the values of Kp and Kc for this reaction at 1100 K 15.81 Nitric oxide (NO) reacts readily with chlorine gas as follows: NO1g2 + Cl21g2 ∆ NOCl1g2 NiO1s2 + CO1g2 ∆ Ni1s2 + CO21g2 At 1600 K, the equilibrium constant for the reaction is Kp = 6.0 * 102 If a CO pressure of 150 torr is to be ­employed in the furnace and total pressure never exceeds 760 torr, will reduction occur? 15.86 Le Châtelier noted that many industrial processes of his time could be improved by an understanding of chemical equilibria For example, the reaction of iron oxide with carbon monoxide was used to produce elemental iron and CO2 according to the reaction Fe2O31s2 + CO1g2 ∆ Fe1s2 + CO21g2 Even in Le Châtelier’s time, it was noted that a great deal of CO was wasted, expelled through the chimneys over the furnaces Le Châtelier wrote, “Because this incomplete reaction was thought to be due to an insufficiently prolonged contact between carbon monoxide and the iron ore [oxide], the dimensions of the furnaces have been increased In England, they have been made as high as 30 m But the proportion of carbon monoxide escaping has not diminished, thus demonstrating, by an experiment costing several hundred thousand francs, that the reduction of iron oxide by carbon monoxide is a limited reaction Acquaintance with the laws of chemical equilibrium would have permitted the same conclusion to be reached more rapidly and far more economically.” What does this anecdote tell us about the equilibrium constant for this reaction? 668 chapter 15 Chemical Equilibrium [15.87] At 700 K, the equilibrium constant for the reaction CCl41g2 ∆ C1s2 + Cl21g2 is Kp = 0.76 A flask is charged with 2.00 atm of CCl4, which then reaches equilibrium at 700 K (a) What fraction of the CCl4 is converted into C and Cl2? (b) What are the partial pressures of CCl4 and Cl2 at equilibrium? [15.88] The reaction PCl31g2 + Cl21g2 ∆ PCl51g2 has Kp = 0.0870 at 300 °C A flask is charged with 0.50 atm PCl3, 0.50 atm Cl2, and 0.20 atm PCl5 at this temperature (a) Use the reaction quotient to determine the direction the reaction must proceed to reach equilibrium (b) Calculate the equilibrium partial pressures of the gases (c) What effect will increasing the volume of the system have on the mole fraction of Cl2 in the equilibrium mixture? (d) The reaction is exothermic What effect will increasing the temperature of the system have on the mole fraction of Cl2 in the equilibrium mixture? [15.89] An equilibrium mixture of H2, I2, and HI at 458 °C contains 0.112 mol H2, 0.112 mol I2, and 0.775 mol HI in a 5.00-L vessel What are the equilibrium partial pressures when equilibrium is reestablished following the addition of 0.200 mol of HI? [15.90] Consider the hypothetical reaction A1g2 + B1g2 ∆ C1g2, for which Kc = 0.25 at a certain temperature A 1.00-L reaction vessel is loaded with 1.00 mol of compound C, which is allowed to reach equilibrium Let the variable x represent the number of mol>L of compound A present at equilibrium (a) In terms of x, what are the equilibrium concentrations of compounds B and C? (b) What limits must be placed on the value of x so that all concentrations are positive? (c) By putting the equilibrium concentrations (in terms of x) into the equilibriumconstant expression, derive an equation that can be solved for x (d) The equation from part (c) is a cubic equation (one that has the form ax3 + bx2 + cx + d = 0) In general, cubic equations cannot be solved in closed form However, you can estimate the solution by plotting the cubic equation in the allowed range of x that you specified in part (b) The point at which the cubic equation crosses the x-axis is the solution (e) From the plot in part (d), estimate the equilibrium concentrations of A, B, and C (Hint: You can check the accuracy of your answer by substituting these concentrations into the equilibrium expression.) 15.91 At 1200 K, the approximate temperature of automobile exhaust gases (Figure 15.15), Kp for the reaction CO21g2 ∆ CO1g2 + O21g2 is about * 10-13 Assuming that the exhaust gas (total pressure atm) contains 0.2% CO, 12% CO2, and 3% O2 by volume, is the system at equilibrium with respect to the CO2 reaction? Based on your conclusion, would the CO concentration in the exhaust be decreased or increased by a catalyst that speeds up the CO2 reaction? Recall that at a fixed pressure and temperature, volume % = mol % 15.92 Suppose that you worked at the U.S Patent Office and a patent application came across your desk claiming that a newly developed catalyst was much superior to the Haber catalyst for ammonia synthesis because the catalyst led to much greater equilibrium conversion of N2 and H2 into NH3 than the Haber catalyst under the same conditions What would be your response? Integrative Exercises 15.93 Consider the reaction IO4-1aq2 + H2O1l2 ∆ H4IO6-1aq2; Kc = 3.5 * 10-2 If you start with 25.0 mL of a 0.905 M solution of NaIO4, and then dilute it with water to 500.0 mL, what is the concentration of H4IO6- at equilibrium? [15.94] Silver chloride, AgCl(s), is an “insoluble” strong electrolyte (a) Write the equation for the dissolution of AgCl(s) in H2O1l2 (b) Write the expression for Kc for the reaction in part (a) (c) Based on the thermochemical data in Appendix C and Le Châtelier’s principle, predict whether the solubility of AgCl in H2O increases or decreases with increasing temperature (d) The equilibrium constant for the dissolution of AgCl in water is 1.6 * 10-10 at 25 °C In addition, Ag +1aq2 can react with Cl-1aq2 according to the reaction [15.96] The phase diagram for SO2 is shown here (a) What does this diagram tell you about the enthalpy change in the reaction SO21l2 ¡ SO21g2? (b) Calculate the equilibrium constant for this reaction at 100 °C and at °C (c) Why is it not possible to calculate an equilibrium constant between the gas and liquid phases in the supercritical region? (d) At which of the three points marked in red does SO21g2 most closely approach ideal-gas behavior? (e) At which of the three red points does SO21g2 behave least ideally? 10 Ag +1aq2 + Cl-1aq2 ∆ AgCl2-1aq2 Supercritical region Liquid Critical point where Kc = 1.8 * 10 at 25 °C Although AgCl is “not soluble” in water, the complex AgCl2- is soluble At 25 °C, is the solubility of AgCl in a 0.100 M NaCl solution greater than the solubility of AgCl in pure water, due to the formation of soluble AgCl2- ions? Or is the AgCl solubility in 0.100 M NaCl less than in pure water because of a Le Châtelier-type argument? Justify your answer with calculations (Hint: Any form in which silver is in solution counts as “solubility.”) [15.95] Consider the equilibrium A ∆ B in which both the forward and reverse reactions are elementary (single-step) reactions Assume that the only effect of a catalyst on the reaction is to lower the activation energies of the forward and reverse reactions, as shown in Figure 15.14 Using the Arrhenius equation (Section 14.5), prove that the equilibrium constant is the same for the catalyzed reaction as for the uncatalyzed one Pressure (atm) 10 Gas 10−1 100 200 Temperature (°C) 300 Design an Experiment [15.97] Write the equilibrium-constant expression for the equilibrium C1s2 + CO21g2 ∆ CO1g2 The table that follows shows the relative mole percentages of CO21g2 and CO(g) at a total pressure of atm for several temperatures Calculate the value of Kp at each temperature Is the reaction exothermic or endothermic? 850 Co2 1mol % 6.23 Co 1mol % 950 1.32 98.68 1050 0.37 99.63 1200 0.06 99.94 Temperature °C 93.77 15.98 In Section 11.5, we defined the vapor pressure of a liquid in terms of an equilibrium (a) Write the equation representing the equilibrium between liquid water and water vapor and the corresponding expression for Kp (b) By using data in Appendix B, give the value of Kp for this reaction at 30 °C (c) What is the value of Kp for any liquid in equilibrium with its vapor at the normal boiling point of the liquid? 669 15.99 Water molecules in the atmosphere can form hydrogenbonded dimers, 1H2O22 The presence of these dimers is thought to be important in the nucleation of ice crystals in the atmosphere and in the formation of acid rain (a) Using VSEPR theory, draw the structure of a water dimer, using dashed lines to indicate intermolecular interactions (b) What kind of intermolecular forces are involved in water dimer formation? (c) The Kp for water dimer formation in the gas phase is 0.050 at 300 K and 0.020 at 350 K Is water dimer formation endothermic or exothermic? 15.100 The protein hemoglobin (Hb) transports O2 in mammalian blood Each Hb can bind O2 molecules The equilibrium constant for the O2 binding reaction is higher in fetal hemoglobin than in adult hemoglobin In discussing protein oxygen-binding capacity, biochemists use a measure called the P50 value, defined as the partial pressure of oxygen at which 50% of the protein is saturated ­Fetal hemoglobin has a P50 value of 19 torr, and adult hemoglobin has a P50 value of 26.8 torr Use these data to ­e stimate how much larger Kc is for the aqueous reaction O21g2 + Hb1aq2 ¡ 3Hb1O2241aq24 Design an Experiment The reaction between hydrogen and iodine to form hydrogen iodide was used to illustrate Beer’s law in Chapter 14 (Figure 14.5) The reaction can be monitored using visible-light spectroscopy because I2 has a violet color while H2 and HI are colorless At 300 K, the equilibrium constant for the reaction H21g2 + I21g2 ∆ HI1g2 is Kc = 794 To answer the following questions assume you have access to hydrogen, iodine, hydrogen iodide, a transparent reaction vessel, a visible-light spectrometer, and a means for changing the temperature (a) Which gas or gases concentration could you readily monitor with the spectrometer? (b) To use Beer’s law (Equation 14.5) you need to determine the extinction coefficient, e, for the substance in question How would you determine e? (c) Describe an experiment for determining the equilibrium constant at 600 K (d) Use the bond enthalpies in Table 8.4 to estimate the enthalpy of this reaction (e) Based on your answer to part (d), would you expect Kc at 600 K to be larger or smaller than at 300 K? 16 Acid–Base Equilibria The acids and bases that you have used so far in the laboratory are probably solutions of relatively simple inorganic substances, such as hydrochloric acid, sulfuric acid, sodium hydroxide, and the like But acids and bases are important even when we are not in the lab They are ubiquitous, including in the foods we eat The characteristic flavor of the grapes shown in the opening photograph is largely due to tartaric acid 1H2C4H4O62 and malic acid 1H2C4H4O52 (Figure 16.1), two closely related (they differ by only one O atom) organic acids that are found in biological systems Fermentation of the sugars in the grapes ultimately forms vinegar, the tangy, sour flavor of which is due to acetic acid 1CH3COOH2, a substance we discussed in Section 4.3 The sour taste of oranges, lemons, and other citrus fruits is due to citric acid 1H3C6H5O72, and, to a lesser extent, ascorbic acid 1H2C6H6O62, better known as Vitamin C Acids and bases are among the most important substances in chemistry, and they affect our daily lives in innumerable ways Not only are they present in our foods, but acids and bases are also crucial components of living systems, such as the amino acids that are used to synthesize proteins and the nucleic acids that code genetic information Both citric and malic acids are among several acids involved in the Krebs cycle (also called the citric acid cycle) that is used to generate energy in aerobic organisms The application of acid–base chemistry has also had critical roles in shaping modern society, including such human-driven activities as industrial manufacturing, the creation of advanced pharmaceuticals, and many aspects of the environment The impact of acids and bases depends not only on the type of acid or base, but also on how much is present The time required for a metal object immersed in water to corrode, the ability of an aquatic environment to support fish and plant life, the fate of pollutants washed out of the air by rain, and even the rates of reactions that maintain What’s Ahead 16.1 Acids and Bases: A Brief Review  We begin by reviewing the Arrhenius definition of acids and bases 16.2 Brønsted–Lowry Acids and Bases  We learn that a Brønsted–Lowry acid is a proton donor and a Brønsted–Lowry base is a proton acceptor Two species that differ by the presence or absence of a proton are known as a conjugate acid–base pair 16.3 The Autoionization of Water  We see that the autoionization of water produces small quantities of H3O+ and OH− ions The equilibrium constant for autoionization, ▶ Clusters of grapes and balsamic vinegar Grapes contain several acids that contribute to their characteristic flavor The distinctive flavor of all vinegars is due to acetic acid Balsamic vinegar is obtained by fermenting grapes Kw = [H3O+][OH−] defines the relationship between H3O+ and OH− concentrations in aqueous solutions 16.4 The pH Scale  We use the pH scale to describe the acidity or basicity of an aqueous solution Neutral solutions have a pH = 7, acidic solutions have pH below 7, and basic solutions have pH above 16.5 Strong Acids and Bases  We categorize acids and bases as being either strong or weak electrolytes Strong acids and bases are strong electrolytes, ionizing or dissociating completely in aqueous solution Weak acids and bases are weak electrolytes and ionize only partially 16.6 Weak Acids  We learn that the ionization of a weak acid in water is an equilibrium process with an equilibrium constant Ka that can be used to calculate the pH of a weak acid solution 16.7 Weak Bases  We learn that the ionization of a weak base in water is an equilibrium process with equilibrium constant Kb that can be used to calculate the pH of a weak base solution 16.8 Relationship between Ka and Kb  We see that Ka and Kb are related by the relationship Ka × Kb = Kw Hence, the stronger an acid, the weaker its conjugate base 16.9 Acid–Base Properties of Salt Solutions We learn that the ions of a soluble ionic compound can serve as Brønsted–Lowry acids or bases 16.10 Acid–Base Behavior and Chemical Structure  We explore the relationship between chemical structure and acid–base behavior 16.11 Lewis Acids and Bases  Finally, we see the most general definition of acids and bases, namely the Lewis acid–base definition A Lewis acid is an electron-pair acceptor and a Lewis base is an electron-pair donor Index Open system, 169 Opsin, 372–73 Optical isomers (enantiomers), 1016–18, 1067 Optically active molecules, 1018 Orbital diagram, 237–39 electron configurations and, 237–39 Orbital overlap, 358–59 Orbitals atomic (See Atomic orbitals) hybrid, molecular geometry, and, 359–65 molecular (See Molecular orbitals (MO)) radial probability functions for, 261 valence, 256 Ores, 998 Organic chemistry, 69 chirality in, 1067 compounds with carbonyl group aldehydes and ketones, 1061–62, 1087 amine and amides, 1066 carboxylic acids, 1062–65 esters, 1062–65 functional groups, 1043, 1058–66 alcohols, 1058–61 aldehydes and ketones, 1061–62 amine and amides, 1066 carboxylic acids and esters, 1062–65 ethers, 1061 general characteristics of organic molecules, 1042–43 hydrocarbons, 69–71, 1044–50 alkenes, 1051–53 alkynes, 1053–54 aromatic, 1044, 1056 branched-chain, 1045 saturated (alkanes), 70–71, 1044, 1045–49 straight-chain, 1045 Organic compounds, 62, 69–71 volatile, 800 Organic molecules, structures of, 1042 Organic substances, stability of, 1043 Orientation factor in reaction rates, 594 Ortho-dichlorobenzene, 339 Ortho isomer, 391 ortho-Phenanthroline, 1008, 1030 ortho- prefix, 1057 Orthorhombic lattice, 484 Osmosis, 554–57 biological examples of, 557 defined, 554 in living systems, 555–57 reverse, 795–96 through red blood cell walls, 556 Osmotic pressure, 548, 554–55, 557–58 calculating, 556 molar mass from, 557–58 Ostwald process, 975 -ous suffix, 63, 67 Outer-shell electrons, 239, 244 Overall reaction order, 584 Overlap, orbital, 358–59 Oxalate ion, 1008, 1029–30 Oxalic acid, 721 acid-dissociation constant of, 694 Oxidation, 139–40 of alcohols, 1062 of calcium, 140, 144 of copper, 139, 144–45 of iron, 139, 144, 816 of metals, 142–43 of methane, 850 of sugar glucose, 842 Oxidation numbers (oxidation states), 140–42, 275, 858–59 acidity and, 708 formal charge and, 319 of transition metals, 999– 1001 Oxidation potential, 907 Oxidation reactions, 89 Oxidation-reduction equations, 860–65 Oxidation-reduction (redox) reactions, 138–45, 858–65 activity series and, 143–45 balancing, 860–65 in basic solution, 863–65 half-reaction method, 860–63 in batteries, 886 corrosion, 891–93 of iron, 891–93 defined, 138 determing the occurrence of, 145 disproportionation, 905, 976 electron movement in, 860, 861, 862, 867–68 free energy and, 876–79 molecular and net ionic equations for, 143 of nitrogen, 612 oxidation numbers (oxidation states), 140–42 oxidation of metals by acids and salts, 142–43 spontaneity of, 865, 876–77 in voltaic cells, 865–68 concentration cells, 882–86 emf in, 868–76 Oxide ion, 66, 275, 278, 284 Oxide(s), 968–69 acidic, 968 amphoteric, 758–59 basic, 968–69 of boron, 987 of carbon, 981–82 of nitrogen, 975–76 sulfur, 971–72 Oxidizing agent (oxidant), 859 Oxyacetylene, 1053 Oxyacids, 707–8, 966 of halogens, 966 of nitrogen, 975–76 sulfur, 971–72 Oxyanions, 64, 65, 966 common, 64 of halogens, 966 as oxidizing agent, 874 of sulfur, 971–72 Oxy compounds of phosphorus, 978–80 Oxygen (O), 8, 461, 961, 966–70 aerobic bacteria and, 795 allotropes of, 283, 289 (See also Ozone) in atmosphere, 400, 777 in blood, 737 dioxygen, 283 dissociation energy of, 779 electron configuration of, 256 elemental, 256 as excess reactant in combustion reactions, 107 formation of, 939 in green chemistry, 800 Lewis symbol for, 300 methane reacting with, 83 molar mass of, 94 molecular, 4, 9, 56 bonding in, 383–84 combustion reactions with, 955 critical temperature and pressure in, 461 Lewis structure for, 383 paramagnetism of, 383–84 photodissociation of, 779, 781 photoionization of, 805 properties of, 777 molecular forms of, 283 oxidation number of, 141 oxides of, 968–69 as oxidizing agent, 874, 966, 967 I-23 paramagnetism of, 383–84 peroxides, 969–70 2p orbital filling in, 270 production of, 967 properties of, 9, 283, 967 reactions with sulfur tetrafluoride, 396 reactions of with alkali metals, 278–79 with cesium, 279 dissolution in water, 794–95 with hydrogen, 169, 171, 179 with metals, 274 with methane, 83 with nickel, 274 with nitric oxide, 826 with potassium, 279 with rubidium, 279 solubility of, 547 superoxides, 969–70 uses of, 967 Oxygen anions, 284 Oxygen atom, Oxygen-demanding wastes, 795 Oxygen group See Group 6A elements (chalcogens) Oxyhemoglobin, 1009, 1010, 1037 Oxymyoglobin, 1010 Ozone, 56, 191, 205, 283–84, 395, 967–68, 1063 in atmosphere, 777, 780–82, 968 chemical properties of, 284 concentration in air, 119 decomposition of, 666 molecular structure for, 320 odor of, 284 photodissociation of, 781 reaction with chlorine, 782–83 resonance structures in, 320 satellite monitoring of, 782 in smog, 787 in Southern Hemisphere, September 24, 2006, 782 water disinfection with, 796–98 Ozone hole, 782, 783 “Ozone Hole Watch” website, 782 Ozone layer, 255, 781–82 depletion of, 782–83 halogen-containing molecules and, 592 Ozone shield See Ozone layer Pacemaker cells, 885 Packing efficiency, 488, 490–91 I-24 Index Packing efficiency (continued) calculating, 490–91 defined, 490 Paired electrons, 237, 239 Palladium(II), 1004 Paper chromatography, 14 Paraffins, 1050 Para isomer, 391 Parallelepipeds, 484 Parallel spins, 238 Paramagnetism, 383–84, 1001, 1021 para- prefix, 1057 para-Xylene, 800 Partial charges, 310, 319 Partial pressures, 415–17 defined, 415 mole fractions and, 417–18 pressure-volume changes and, 654 Particle accelerators, 918–19 Parts per billion (ppb), 544 Parts per million (ppm), 544, 777, 778 Pascal (Pa), 402, 829n Pascal, Blaise, 402 Paschen series, 253 Pauli, Wolfgang, 235 Pauli exclusion principle, 235–36 Pauling, Linus, 309 p-block elements, electron configurations of ions of, 305–6 Pearlite, 492, 493 “Pebble-bed” reactor design, 936 p elements, electron affinities for, 272 Pentane, 1045, 1046 Pentanol, 539 penta- prefix, 68 Pentene, isomers of, 1052–53 Peptide bonds, 1070–71 Pepto-Bismol, 287 Percentage composition, 91 empirical formula from, 98 Percent ionization, 689, 692–94 concentration and, 693 using the quadratic equation to calculate, 693–94 Percent yield, 109–10 Perchlorate, 966 Perchlorate ion, 64, 65, 66 Perchloric acid, 134, 708, 966 Period diatomic molecules, 376–86 Periodic properties of elements, 256–97 atomic radii, 264–65 periodic trends in, 264–65 atoms and ions, sizes of, 262–67 effective nuclear charge (Zeff ), 259–62, 260 electron affinities, 272–73 group trends for active metals, 278–82 alkali metals (group 1A), 278–81 alkaline earth metals (group 2A), 281–82 group trends for nonmetals, 282–88 halogens (group 7A), 284–86 hydrogen, 282–83 noble gases (group 8A), 286–88 oxygen group (group 6A), 283–84 ionic radii, 265–67 periodic trends in, 265–67 ionization energy, 268–72 electron configurations of ions and, 271–72 periodic trends in first, 269–71 variation in successive, 268–69 metalloids, 277 metals, 274–76 nonmetals, 276–77 periodic table, development of, 258–59 Periodic table, 8, 52–55 development of, 258–59 electron configurations and, 241–45 groups in, 53, 54 ionic charges and, 60 metallic elements or metals, 53, 55 metalloids, 55 nonmetallic elements or nonmetals, 53, 55 periods of, 53–54 Periodic trends, 952–56 in atomic radii, 264–65 in first ionization energies, 269–71 in ionic radii, 265–67 Periods, 53–54 Permanent magnet, 1001 Permanganate half-reaction, 861 Permanganate ion, 66, 1028 Peroxidase, 970 Peroxide ion, 66, 279, 284, 289, 393, 969 Peroxides, 284, 969–70 per- prefix, 64, 65, 68 Perspective drawing, 57, 58 PES (photoelectron spectroscopy), 296, 297 PET (polyethylene terephthalate), 510, 511, 800 PET (positron emission tomography), 928 Peta prefix, 16 Petroleum, 197, 1050 global population growth and demand for, 198 pH, 680–84 See also Acidbase equilibria; Aqueous equilibria of buffer, 731–34 calculating, involving common ion, 726–27 calculating acid-dissociation constant from, 688–89 calculating from aciddissociation constant, 690–92 calculating from polyprotic acid, 695–96 of common substances, 683 determining, using concentration cell, 885–86 measuring, 683–84 salt effects on, 702–5 of seawater, 753 solubility and, 753–55 of strong acid, 685 of strong base, 685–86 titration curve, 738 using the quadratic equation to calculate, 693–94 Phase changes in liquids, 457–61 critical temperature and pressure, 460–61 energy changes accompanying, 457–59 entropy change and, 819–20 heating curves, 459–60 Phase diagrams, 464–67, 551–52 illustrating boiling-point elevation, 551 illustrating freezing-point depression, 552 Phases in atomic and molecular orbitals, 379–80 condensed, 444 Phenol, 1060 properties of, 502 Phenol acid, 687 Phenolphthalein, 152, 153, 684, 745–46 Phenylacetic acid, 718 Phenylalanine, 1069, 1070 Phenylamine, 1066 Phenylmethanamide, 1066 Phenyl methanoic acid (benzoic acid), 185, 186, 687, 709, 718, 1062 pH meter, 683, 883 Phosgene, 331, 351, 637 Phosphate ion, 65, 66 Lewis structures for, 325 Phosphates insoluble, 763 as sequestering agents, 1009 Phosphine, 461 Phospholipids, 1077 Phosphoric acid, 965, 979 acid-dissociation constant of, 694 sale of, Phosphorous acid, 712–13, 979 Phosphorus–32, 928 Phosphorus (P), 8, 311, 324, 341, 494, 504, 506 allotropes of, 978 elemental, 341 halides of, 978 Lewis symbol for, 300 nonbonding electron pairs in, 494 occurrence, isolation, and properties of, 977–78 oxy compounds of, 978–80 properties of, 977–78 red, 978 silicon doping with, 506 white, 978 Phosphorus halides, 978 Phosphorus(III) oxide, 978 Phosphorus pentachloride, 664 Phosphorus pentafluoride, 324 Phosphorus trichloride, 978 Phosphorus trihalides, 396 Phosphorus(V) oxide, 978 Photochemical smog, 610, 786–87 See also Smog Photocopiers, 971 Photodissociation, 778–83, 805 of ClO, 783 defined, 779 of NO2, 787 of oxygen, 779, 781 of ozone, 781 Photoelectric effect, 216, 217–18 Photoelectron spectroscopy (PES), 296, 297 Photographic plates/film, 926 Photoionization, 778, 780, 805 Photoluminescence, 515, 521 Photon(s), 217–18 Photoreceptors, 372 Photosynthesis, 164, 175, 199, 210, 211, 1011 Photovoltaic cells, 164, 250 pH range, 734 pH titration curve, 738, 740 Physical changes, 12–13 Physical properties, 11, 40 Phytoplankton, 753 pi (p) bonds, 366–73, 954 in alkenes, 1052–53 in aromatic hydrocarbons, 1056–57 Index in chemistry of vision, 372–73 delocalized, 370 in double bonds, 366 in ozone, 968 strength of, 366 in triple bonds, 366 Pico prefix, 16 pi (p) molecular orbitals, 378–79 in aromatic hydrocarbons, 1056–57 Pipelines, gas, 440 Pipette, 19 Pipevine swallowtail caterpillar, 202 Planck, Max, 216–17, 219, 220 Planck’s constant, 217 Plastic electronics, 513–14 Plastics, 508–9 elastomer, 508–9 electronics, 513–14 polycarbonate, 510 recycling, 511 thermoplastics, 508 thermosetting plastic, 508–9 types of, 508–9 Platinum, 626 oxidation in aqueous solution, 144 Platinum(II), 1007 Plato, 42 Plumber’s solder, 491 Plumbous or lead(II) ion (Pb2+), 63 Plum-pudding model of the atom, 46 Plutonium–239, 932, 936–37 Plutonium (Pu), 241, 920 p-n diode, 507 pOH, 682–83 Polar covalent bond, 309, 310 Polarity acidity for binary acids and, 706 bonding, 309–15 molecular (bond), 356–58 proton transfer reactions and, 673–74 solubility and, 538–40 Polarizability, 447–48 Polar liquids, solubility of, 538 Polar molecules, 312, 356–57, 447–48 Pollutants atmospheric, 784 CFCs, 592, 782, 790 environmental, 793 gases, 776, 784 hydrocarbons, 784, 787 nitrogen oxides, 782, 784, 786–87 sulfur dioxide, 784 unburned hydrocarbons as, 787 in urban atmosphere, 784 Pollution air, 610 real-time analysis for prevention of, 799 smog, 786–87 water, 979 Polonium–218, 942 Polonium (Po), 45, 283, 970 Polyacetylene, 517–18 Polyacrylonitrile, 526 Polyatomic ions, 59, 64, 315, 317, 323–24 Polycarbonate, 510 Polychloroprene, 526 Polychromatic radiation, 219 Polydentate ligands (chelating agents), 1007–9, 1033 Polyesters, 509, 529 Polyethylene, 71, 508, 509, 510 annual production of, 509 high-density, 511, 512 low-density, 511, 512 properties of, 511–12 structure of, 511–12 Polyethylene terephthalate (PET), 510, 511, 800 Polymeric solids, 508 Polymerization, 507 addition, 509 condensation, 509–10 Polymer(s), 480, 482, 507–14 addition, 510 biopolymers, 1068 co–, 510 commercially important, 510 condensation, 510 conducting, 517 cross-linking of, 512–13 crystallinity, 512 elastomeric, 508–9, 854 making, 509–11 structure and physical properties of, 511–14 types of, 508–9 Polynucleotide, 1079 Polypeptides, 1070–71 Polyphosphate, 515 Polypropylene, 510, 511, 529 Polyprotic acids, titrations of, 746–47 Polysaccharides, 1075–76 Polystyrene, 510, 511 Polytetrafluoroethylene (Teflon), 800, 964 Polyunsaturated fatty acids, 1076 Polyurethane, 510, 810 Poly(vinyl alcohol), 355 Polyvinyl chloride (PVC), 510, 511, 964 Population, global growth of, 198 p orbitals, 233 energy-level diagrams/ electron configurations, 381–82 periodic trends and, 952–56 phases in, 379–80 radial probability functions of, 261 2p orbitals, molecular orbitals from, 377–80 Porphine molecule, 1009 Porphyrins, 1009 Positron, 913 Positron emission, 913 Positron emission tomography (PET), 928 Potassium–40, 943–44 Potassium (K), 8, 52, 212, 240 condensed electron configuration of, 240 oxidation in aqueous solution, 144 properties of, 278t reaction with oxygen, 279 in seawater, 792 Potassium chlorate, 966, 967 Potassium dichromate, 1063 Potassium iodide, 128–29 Potassium ion, 63 Potassium nitrate, 129 Potassium superoxide, 279, 297, 969 Potential difference, 868 Potential energy, 166–68, 170 electrostatic, 166–68 free energy and, 832 Powdered limestone, 786 ppb (parts per billion), 544 ppm (parts per million), 544, 777, 778 Practice, importance of, 31 Praseodymium (Pr), 241 Precipitate, 128 Precipitation, 128–32 exchange (metathesis) reactions, 130–31 of ionic compounds, 748 solubility guidelines for, 129–30 ionic equations, 131–32 of ions, 759–62 selective, 760–62 Precision, 22 Prefixes binary compounds, 68 Greek, 68, 1013 metric system, 16 Prepolarized MRI, 236 Pressure, 175, 178, 401–4 atmospheric, 176, 178, 190, 205, 401–4 I-25 blood, 404 critical, 460–61 defined, 401 equilibria and, 652–54 equilibrium constants in terms of, 635–36 gas, 401–4 intermolecular forces and, 445–46 Le Châtelier’s principles and, 651 osmotic, 548, 554–55, 557–58 partial, 415–17 mole fractions and, 417–18 real vs ideal gas behavior and, 426–28 solubility and, 541–43 spontaneous processes and, 815 standard, 829n temperature changes on, 411 vapor, 461–64 Pressure-volume relationship, 404–5 Pressure-volume (P-V) work, 175–76, 178 Pressurized water reactor, 935 Priestley, Joseph, 966 Primary cells (batteries), 886 Primary coolant, 934, 935 Primary structure, of proteins, 1071, 1072 Primary valence, 1003 Primitive cubic lattice, 485, 487, 499 Primitive cubic unit cell, 488 Primitive lattice, 484 Principal quantum number (n), 221, 228, 229, 230, 234, 235, 238, 243–44 Probability, entropy and, 822 Probability density, 227, 379 Products, 82 calculating amounts of, 105–6 from limiting reactant, 108–9 change in concentration of, 651–52 enthalpy change and state of, 179–80, 187–89, 190, 192–93 states of, 85 Proline, 1069 Propane, 69, 70, 400, 438, 461, 1044, 1045 carbon-carbon backbone of, 1042 combustion of, 89, 192–94, 835 critical temperature and pressure of, 461 I-26 Index Propane (continued) enthalpy diagram for combustion of, 192 in natural gas, 197 properties of, 449 rotation about carboncarbon single bonds of, 1045 standard enthalpy of formation for, 190 states of, 446 1,2,3-Propanetriol (glycerol), 1060, 1076, 1077 Propanol, 539, 849 1-Propanol, 70 1-Propanol, hydrogen bonding in, 453–54 2-Propanol (isopropyl alcohol), 70, 101–2, 1060 Propanone (acetone), 158, 1059, 1061, 1062 Propene (propylene), 6, 392, 1050, 1051 Propenoic acid, 116 Property, Propionic acid, 719 Propofol, 21 Propyl alcohol, 473 Propylene, 6, 392, 1051 Propyl group, 1047 Propyne, 356 Protein(s), 195, 507, 526, 1068–73 amino acids, 1068–70 amphiprotic behavior of, 709–10 side chain of, 1071 carbon group in, 61 composition and fuel value of, 195 defined, 1068 DNA structure and synthesis of, 1079–80 as enzymes, 610 fibrous, 1072 globular, 1009, 1072 metabolism of, 195 and polypeptides, 1070–71 structure of, 1071–73 Protein sequence, 1088 Protium, 956 Proton donors, 133 Proton(s), 46, 47, 48, 910, 912 mass of, 48 neutron-to-proton ratio, 914–16 Proton-transfer reactions, 673–74 Proust, Joseph Louis, 10 “p” scales, 682–83 p-type semiconductor, 506–7 Pure substances, 7, 11 crystalline, 827, 828 Purines, 1088 Putrescine, 701 PVC (polyvinyl chloride), 510, 511, 964 Pyrene, 1056 Pyrex, 987 Pyridine, 697, 1034 Pyrimidines, 1088 Pyrite (fool’s gold), 971 Pyrosulfuric acid, 971 Pyruvic acid, 1080–81 Qualitative analysis for metallic elements, 762–64 Quantitative analysis, 762 Quantitative information, from balanced equations, 103–6 Quantitative properties, 14 Quantity-volume relationship, 406–7 Quantized energy, 216–18 Quantum, 217 Quantum dots, 119, 514–15 Quantum mechanics, 212, 226 See also Wave mechanics Quantum number angular momentum (I), 228, 230 magnetic (ml), 228, 235, 237–38 orbitals and, 228–30 principal (n), 221, 228–29, 235, 238, 243–44 spin magnetic (ms), 235, 237–38 Quantum theory, 212, 217, 227–28 Quantum wells, 515 Quantum wires, 515 Quartz, 483, 503, 522, 986, 987 Quartz glass (silica glass), 987 Quaternary structure, of protein, 1072, 1073 Quicklime (calcium oxide), 88, 983 standard enthalpy of formation for, 190 Quinine, 701, 1089 Racemic mixtures, 1018, 1067 rad (radiation absorbed dose), 940 Radial probability density, 230 Radial probability function, 231, 232, 261 Radiant energy, 214 See also Electromagnetic radiation Radiation, 186 alpha (a), 45–46, 911, 912, 913, 938, 939, 940 background, 941 beta (b), 45–46, 912, 938, 940 biological effects of, 936, 938 dosage and, 940–41 radon, 942 therapeutic, 928, 943 gamma (g), 45–46, 913, 938, 940, 943 ionizing, 938 microwave, 215, 255 monochromatic, 219 nonionizing, 938 polychromatic, 219 Radiation therapy, 928, 943 Radicals, free, 940 Radioactive decay, 911, 912–14 calculating age of objects using, 924 rates of, 920–25 types of, 912–14 Radioactive series (nuclear disintegration series), 916 Radioactivity, 45–46, 910–14 detection of, 926–27 Radiocarbon dating, 921–23 Radioisotopes, 911, 943 Radiometric dating, 921–23 Radionuclides, 911 Radiotracers, 927–28 medical applications of, 928 Radio waves, 780 Radium–226, 912, 948 Radium (Ra), 45 electron configuration of, 241 Radius See Atomic radius/radii; Ionic radii Radon, 286, 571, 942, 961 properties of, 286 radioactivity of, 286 Radon–222, 942 Radon (Rn), 241 Radon-testing kits, 942 Rainwater, 277, 784 uncontaminated, 784 (R)-Albuterol, 1067 Randomness See Entropy(ies) Raoult’s law, 549, 550–51 Rare earth elements, 240–41 See also Lanthanides Rate constants, 583, 586 temperature and, 594 units of, 585 Rate-determining (ratelimiting) step, 602–3 Rate laws, 581–87 concentration and, 581–87 differential, 587 for elementary steps, 601–2 exponents in, 584 H+ concentration and, 681 initial rates to determine, 586–87 integrated, 587–88, 590 for multistep mechanisms, 602–3 units of rate constant, 585 RBE (relative biological effectiveness), 940 RDX (cyclotrimethylenetrinitramine), 340 Reactants (reagents), 82 calculating amounts of, 105–6 catalytic, 799 change in concentration of, 651–52 enthalpy change and state of, 179–80, 187–89, 190, 192–93 environment-friendly, 800–802 excess, 107 greener, 800–802 limiting (limiting reagents), 106–11 theoretical yields, 109–10 physical state of, 576 states of, 85 Reaction mechanisms, 576, 599–606 defined, 599 elementary reactions, 599 rate laws for, 601–2 with fast initial step, 604–6 multistep, 600–601 rate-determining step for, 602–3 with slow initial step, 603–4 Reaction orders, 584 Reaction quotient (Q), 646–47, 759 Reaction rates, 576–81 average, 578 catalysis and, 577, 606–13 enzymes, 609–13 heterogeneous, 608–9 homogeneous, 607–8 concentration and, 576, 577 change with time, 587–93 rate laws, 581–87 defined, 574, 577 factors affecting, 576–77 instantaneous (initial rate), 579–80 spectroscopic methods to measure, 582–83 stoichiometry and, 580–81 temperature and, 576, 593–99 activation energy, 594– 95, 597–99 Arrhenius equation for, 596 collision model of, 594 orientation factor in, 594 Index time and, 577, 580, 587–93 for weak and strong acids, 692 Reaction(s), 12, 82 acid-base, 132–38 (See also Acid-base equilibria) electrolytes, 135 with gas formation, 138 neutralization reactions and salts, 135–37 addition of alkenes and alkynes, 1054–56 mechanism of, 1055–56 of alkanes, 1049 anaerobic, 199 bimolecular, 599 carbonylation, 852, 1063 chain, 932 chemiluminescent, 593 click, 802 combustion, 82, 89 balanced equations for, 89 with oxygen, 955 condensation, 979, 1061 with alcohol, 1063 decarbonylation, 850 displacement, 142 disproportionate, 976 elementary, 599, 601–2 endothermic, 174, 177, 184 enthalpies of, 179–81, 327–29 entropy changes in, 828–31 exothermic, 174, 177, 179, 184 first-order, 584, 587–89, 592 Friedel-Crafts, 1058 gas-phase, 674 gas volumes in, 414–15 half-life of, 591–93 heat of, 179–81 involving nonmetals, 955–56 ligand exchange, 1038 mechanisms, 576 mechanisms of (See Reaction mechanisms) nonspontaneous, 836, 842 nuclear (See Nuclear chemistry) periodic trends and, 955–56 predicting the direction of, 646–47 proton-transfer, 673–74 rates of (See Reaction rates) redox (See Oxidationreduction (redox) reactions) second-order, 589–91, 593 solution formation and, 535–36 spontaneity of (See Spontaneous processes) substitution, 1057–58 termolecular, 599 thermite, 174, 207 thermonuclear, 937 unimolecular, 599 water, 122 zero-order, 591 Reactivity, patterns of, 86–89 combinations and decomposition reactions, 86–88 combustion reactions, 89 Reactors, nuclear, 934–36 Reagents See Reactants (reagents) Real gases, 426–30 van der Waals equation, 428–30 Rectangular lattice, 483–84 Recycling symbols, 511 Red blood cells, 737 osmosis and, 555–56 sickle (crescent-shaped) and normal, 562 Red giant phase, 939 Red ochre, 1029 Redox reactions, 858–65 see also Oxidation–reduction (redox) reactions Red phosphorus, 978 Reducing agent (reductant), 859 strengths of, 874 Reduction See Oxidationreduction (redox) reactions Refining, 1050 Reforming, 1050 Refrigerant, 852 carbon dioxide as, 982 Reinecke’s salt, 1012 Reinitzer, Frederick, 467 Relative biological effectiveness (RBE), 940 Relativistic Heavy Ion Collider (RHIC), 919 rem (roentgen equivalent for man), 941 Remsen, Ira, 12 Renewable energy, 198 Renewable feedstocks, 799 Representative (main-group) elements, 242 Resonance structures, 320–22, 368–71 in benzene, 322 in nitrate ion, 321 in ozone, 320 Retinal, 372 Reverse osmosis, 795–96 Reversible process, 816–18 R groups, 709, 1069 Rhenium oxide, 528 RHIC (Relativistic Heavy Ion Collider), 919 Rhodopsin, 372–73 Rhombic sulfur, 971 Rhombohedral lattice, 484 Ribonuclease A, 1090 Ribonucleic acid (RNA), 1077 Ribose, 1079 Ring structure, of glucose, 1074 rms speed, 419–20, 421, 422–23 RNA (ribonucleic acid), 1077 Rocket fuel, 958, 966, 974, 995 Rods, 372 Rolaids, 139 Roosevelt, Franklin D., 934 Root-mean-square (rms) speed, 419–20, 421, 422–23 Rotational motion, 824, 825–26 Roth, Bruce, 342 Rounding off numbers, 25 Rowland, F Sherwood, 782 Royal Institution of Great Britain’s Faraday Museum, 515 Rubber, 483, 509, 513 vulcanization of, 513, 971 Rubidium, 279 properties of, 278 reaction with oxygen, 279 Rubidium–87, 938 Rubidium (Rb), 240 Rusting See Corrosion Rutherford, Ernest, 45–47, 259, 918 Rutile, 524, 525 Rutile structure, 500 Rydberg constant, 220, 221 Rydberg equation, 220 Saccharin, 719 Sacrificial anode, 893 SAE (Society of Automotive Engineers), 455 Salinity, of seawater, 792 Salt bridge, 866–67, 882, 890 Saltpeter, 973 Salt(s) See also Sodium chloride acid, 701 chlorate, 966 defined, 136 density of, 20 dissolving of, 826 electrolysis of molten, 893 formula weight of, 93–94 hypochlorite, 966 iodized, 964 naming, 1012 neutralization reactions and, 135–37 oxidation of metals by, 142–43 solubility-pH relationship in, 754 Salt solutions I-27 acid-base properties of, 702–5 anion reaction with water, 702 cation reaction with water, 702–4 combined cation-anion effect, 704–5 conductivity of, 124, 125 Saponification, 1064 Saturated hydrocarbons See Alkanes Saturated solution, 536–37, 748 and solubility, 536–37 s-block elements, electron configurations of ions of, 305–6 Scandium, 240 Scandium fluoride, 500 Scanning tunneling microscopy (STM), 43 Schrödinger, Erwin, 226, 227–28 “Schrödinger’s cat” experiment, 227–28 Schrödinger’s wave equation, 226–27, 228, 232 Scientific law, 15 Scientific method, 15 Scintillation counter, 926 Screening constant (S), 260 Sea urchins, 753 Seawater, 753, 792, 795 desalination of, 795–96 ionic constituents of, 792 Second (s or sec), 15 Secondary cells (batteries), 886 Secondary coolant, 935 Secondary structure, of proteins, 1071, 1072 Secondary valence, 1003 Second ionization energy, 268 Second law of thermodynamics, 820–21 Second order overall, 584 Second-order reactions, 589–91, 593 Seesaw geometry, 353 Selective precipitation of ions, 760–62 s elements, electron affinities for, 272 Selenium (Se), 970–71 electron configuration of, 245 properties of, 283 Semiconductor doping, 506–7 Semiconductors, 277, 296, 480, 504–6 band structure of, 504 compound, 296, 504–5 doping of, 506–7 electrical, 277 I-28 Index Semiconductors (continued) elemental, 504–5 examples of, 504 identifying types of, 507 light-emitting diodes, 480, 507–8, 526 on nanoscale, 514–15 n-type, 506–8 p-type, 506–8 silicon, 277, 296 silicon in, 984 Semimetals, 517 Semipermeable membranes, 554–55, 884 Separation, of ions, 759–62 Sequestering agents, 1009 Serine, 1069, 1070 Serotonin, 119 Serpentine asbestos, 986 Seven Up, 281 SF6, 324 Shape, molecular See Molecular geometry SHE (standard hydrogen electrode), 869–70 Shell model of nucleus, 916 Shivering, 187 Shock sensitive explosives, 330 (S)-Ibuprofen, 1067 Sickle-cell anemia, 562, 1071 Side chain, amino acid, 1045, 1071 Siderite, 983 Siderophore, 1011–12 Sigma (s) bonds, 365–66, 368, 369–70 Sigma (s) molecular orbitals, 374 Sigma (s) symbol, 193 Significant figures, 22–27 in calculations, 25–27 Silica, reaction with hydrofluoric acid, 965 Silica glass (quartz glass), 987 Silicates, 985–87 Silicon (Si), 8, 268, 277, 494, 504, 506–7, 522, 525, 984 doping of, 506–7 electronic properties of, 504 elemental, 277f Lewis symbol for, 300 nonbonding electron pairs in, 494 occurrence and preparation of, 984–85 semiconductor, 277 surface of, 43 Silicon carbide, 503, 527–28, 984 Silicon dioxide, 952, 955, 985 Silicones, 987 Silicon tetrachloride, 72 Silver (Ag), 8, 54, 55, 306 alloys of, 491, 492, 494 corrosion of, 139 mole relationships of, 94 on nanoscale, 516 oxidation of, 143–45 reaction with copper, 144–45 as reducing agent, 877 sterling, 530 Silver chloride, 668 standard enthalpy of formation for, 190 Silver chromate, 749 Silver ion, 63 mole relationships of, 94 Single bonds, 308, 955 bond enthalpies of, 326 carbon–carbon, 322 length of, 329 rotations about, 1045 Single-walled carbon nanotubes, 516 SiO2, 986, 987 SI units, 15–18 base units, 15 density, 20 derived, 19 length and mass, 15, 17 for speed, 19 temperature, 15, 17–18 volume, 19 16-kiloton bomb, 933 Skeleton, carbon-carbon, 1042 Slater, John, 262 Slater’s rules, 262, 291–92, 294, 297 Smalley, Richard, 516 Smectic liquid crystalline phases, 468 Smog, 610, 786–87 defined, 786 major ingredients of, 787 photochemical, 786–87 reduction or elimination of, 787 Soap, 672, 1043, 1064 Society of Automotive Engineers (SAE), 455 Soda-lime glass, 987 Sodium–24, 928 Sodium (Na), 8, 52, 483, 487, 494, 523 condensed electron configuration of, 260 cubic structure of, 499 effective nuclear charge of, 260 electron configuration of, 238 first ionization energy for, 268 ions of, 58 Lewis symbol for, 300 oxidation in aqueous solution, 144 properties of, 278 reactions of with chlorine, 301 with oxygen, 279 in seawater, 792 second ionization energy for, 268 successive values of ionization energies for, 268 Sodium acetate, 537, 726 Sodium azide, 88, 415 Sodium bicarbonate (baking soda), 132, 138 standard enthalpy of formation for, 190 Sodium borohydride, 988 Sodium bromide, 965 Sodium carbonate, standard enthalpy of formation for, 190 Sodium cation, 58 Sodium chloride, 60–61 conductivity of solution of, 124, 125 coordination environments in, 500 crystal structure of, 302 dissolution in water, 533–34, 536, 537 electrolysis of aqueous, 893 molten, 893 formation of, 302 standard enthalpy of formation for, 190 states of, 445 structures of, 499 Sodium fluoride, 500, 755 Sodium formate, 772 Sodium hydroxide, 6, 136, 672 Sodium hypochlorite, 698, 964 Sodium ion, 63 Sodium ion batteries, 294 Sodium lactate, 731–32 Sodium monofluorophosphate, 755 Sodium perchlorate, 951 Sodium propionate, 1064 Sodium silicate, 116 Sodium stearate, 561–62, 573 Sodium sulfate, dissociation of, 125 Sodium tripolyphosphate, 979, 1009 Sodium vapor lamp, 280 Sodium vapor lights, 216, 219 Softening of water, 807 Solar cells (photovoltaic devices), 164, 199 Solar energy, 164, 198–99, 385–86 Solar panels, Solar spectrum, 778 Solder, plumber, 491 Solid(s), amorphous, 483 classifications of, 480–82 concentration of, 641 covalent-network, 482, 503–7 crystalline, 445, 473, 482–83 intermolecular attractive forces in, 444 ionic, 482, 498–502 empirical formula and density of, 501–2 structures of, 498–502 molecular, 482, 502 properties of, 502 molecular comparison of liquids and, 444–46 polymeric, 508–9 properties of, 444, 486–87, 491, 498, 502, 511–14 structures of, 482–86 close packing of spheres, 489 crystal lattices, 483–85 crystalline and amorphous solids, 482–83 unit cells, 483–85 in water, 532–34, 543 Solid solutes, 536, 543 Solid solutions, 492, 530 Solid-state electronics, 212 Solubility, 129, 536–37 amphoterism and, 758–59 common-ion effect and, 751–52 complex ion formation and, 756–58 factors affecting, 538–44 molar, 749 of organic substances, 1043 pH and, 753–55 polarity and, 538–40 pressure effects on, 541–43 saturated solution and, 536–37 solubility-product constant and, 748–51 solubility-product constant vs., 749–51 solute-solvent interactions and, 538–41 temperature effects on, 543 Solubility equilibria, 748–51 solubility-product constant, 749–50 limitations of, 751 solubility equilibria, 759 solubility vs., 749–51 Solubility guidelines, for ionic compounds, 129–30 Solubility-product constant (Ksp), solubility product), 749–51 limitations of, 751 Index Solutes, 124, 530 ionic, 535, 540 molarity to calculate grams of, 149 nonpolar, 540 polar, 540 solid, 536, 543 titration to determine quantity of, 154 Solute-solute interactions, 533, 551 Solute-solvent interactions, 538–41 Solution(s), 10, 11, 124, 530 acidic, 704, 705 aqueous (See Aqueous solution(s)) basic, 704, 705 balancing equations for reactions in, 863–65 buffered blood as, 729, 737 buffer capacity and pH, 734 calculating pH of buffer, 731–34 composition and action of, 729–31 strong acids or bases in, 735–37 colligative properties, 548–59 boiling-point elevation, 551–52 of electrolyte solutions, 558–59 freezing-point depression, 552–54 molar mass determination through, 557–58 osmosis, 554–57 vapor pressure reduction, 548–51 colloids, 559–64 colloidal motion in liquids, 562–64 hydrophilic and hydrophobic, 560–62 removal of colloidal particles, 563 types of, 559 concentration of, 146–51, 544–48 conversion of units of, 547–48 dilution, 149–51 of electrolyte, 147 interconverting molarity, moles, and volume, 148–49 in mass percentage, 544–45 molality, 545–48 molarity, 146–47, 542, 545–46, 548 in mole fraction, 545–46, 547 in parts per billion (ppb), 544–45 in parts per million (ppm), 544–45 defined, 10, 124 formation of, 530, 532 chemical reactions and, 535–36 energetics of, 533–35 intermolecular forces and, 532–33 spontaneity, entropy, and, 532–33 hypertonic, 555 hypotonic, 555 ideal, 550–51 isotonic, 555 neutral, 679, 704 preparing by dilution, 150–51 process, 530–36 saturated, 536–37, 748 solid, 492, 530 standard, 152 stock, 149 supersaturated, 537 unsaturated, 537 Solution stoichiometry, 151–55 titrations, 152–55 acid-base, 738–47 Solvation, 125, 533 Solvent(s), 124, 530 chlorofluorocarbon, 800 conventional, 800 environment-friendly, 799 ethers as, 1061 ketones as, 1062 nonpolar, 535, 539, 540 polar, 538, 540 pure, 551–54, 559 supercritical, 800 volatile solvent, 548, 549 water as, 724 Solvent-solute interactions, 533–35, 551 Solvent-solvent interactions, 533, 551 s orbitals, 230–33 energy-level diagrams/ electron configurations, 381–82 phases in, 379–80 Space-filling models, 57, 344 Space shuttle, 966 Spearmint, 1062 Specific heat, 181–83 Spectator ions, 131 Spectrochemical series, 1023 Spectroscopy, measuring reaction rates with, 582–83 Spectrum, 219 continuous, 219 creating, 219 line, 219 Speed of light, 214 root-mean-square (rms) vs average, 419–20 Spheres, close packing of, 488–89 sp hybrid orbitals, 360–61, 365 sp2 hybrid orbitals, 361–62, 366 sp3 hybrid orbitals, 361–62 Spinel, 528 Spin magnetic quantum number (ms), 235, 237–38 Spin-pairing energy, 1025 Spontaneous processes, 181, 814–18 criterion for, 816 defined, 814 exothermic processes and, 535 expansion of a gas into an evacuated space as, 815 free energy and, 831–34, 836 identifying, 815–16 oxidation-reduction reactions, 865, 876–77 pressure and, 815 reversible and irreversible, 816–18 solution formation and, 532–33, 535 temperature and, 815 Square lattice, 483–84 Square-planar complexes, 1026–30 Square planar geometry, 353, 354, 357, 1007, 1010 Square pyramidal geometry, 353, 354 Stability(ies) belt of, 914–15 nuclear even vs odd number of nucleons, 916 magic numbers and, 916 neutron-to-proton ratio, 914–16 radioactive series (nuclear disintegration series), 916 of organic substances, 1043 Stack, fuel cell, 890 Stained glass, 515 Stainless steel, 491, 492, 891 Stalactites and stalagmites, 209 Standard atmospheric pressure, 402 Standard cell potential, 869 I-29 Standard deviation, 22 Standard emf, 868–76 Standard enthalpy change, 190 defined, 190 denoted as, 190 Standard enthalpy of formation, 190 Standard free-energy change, 833–34, 834–35 Standard free energy of formation, 834–36 Standard hydrogen electrode (SHE), 869–70 Standard molar entropies, 829 of selected substances at 298 K, 829 Standard pressure, 829n Standard reduction (half-cell) potentials, 869–74 Standard solution, 152 Standard state conditions, 190 Standard temperature and pressure (STP), 409 Standing waves, 226, 227 Stannous fluoride, 755 Stannous or tin(II) ion (Sn2+), 63 Star, formation of, 939 Starch, 194, 507, 1075 Starfish, 753 State function(s), 174–75, 816 enthalpy as, 175, 177, 189 internal energy as, 174–75 State(s) changes of, 12 of gas, 404 of matter, of reactants and products, 85 Static equilibrium, 628 Statins, 342 Statistical thermodynamics, 823 Steam turbines, 853 Stearate, 1043 Stearic acid, 568 Steel, 492, 517 stainless, 491, 492, 891 Stereoisomers, 1014, 1015–18 Sterling silver, 491, 530 Stern, Otto, 254 Stern-Gerlach experiment, 254 STM (scanning tunneling microscopy), 43 Stock solutions, 149 Stoichiometrically equivalent quantities, 103 Stoichiometry Avogadro’s number and the mole, 91–98 molar mass, 93–95 calculation, 735, 736 chemical equations, 82–86 balancing, 82–85 states of reactants and products, 85 I-30 Index Stoichiometry (continued) defined, 80 empirical formulas from analyses, 98–102 combustion analysis, 101–2 molecular formula from, 100–101 formula weights, 89–91 percentage composition from formulas, 91 of half-reaction, 894 interconverting masses and moles, 95–96 interconverting masses and numbers of particles, 96–98 limiting reactions (limiting reagent), 106–11 theoretical yields, 109–10 patterns of chemical reactivity, 86–89 combination and decomposition reactions, 86–88 combustion reactions, 88 problem-solving procedure for, 151 quantitative information from balanced equations, 103–6 reaction rates and, 580–81 solution, 151–55 titrations, 152–55 Stony corals, 724, 753 STP (standard temperature and pressure), 409 Straight-chain alkanes, 1045 Straight-run gasoline, 1050 Stratosphere, 776 ozone cycle in, 781 ozone in, 780–82 Strong acids, 133–34, 676, 677, 684–85 added to buffers, 735–37 titration of weak base and, 745–46 Strong acid-strong base titrations, 738–40 Strong bases, 133–34, 685–86 added to buffers, 735–37 Strong electrolytes, 126–28, 684 identifying, 135 Strong-field ligands, 1024 Strong nuclear forces, 49 Strontium–90, 920, 924–25, 948 Strontium (Sr), 281, 293 electron configuration of, 241, 245 properties of, 281 in seawater, 792 Strontium ion, 63 Strontium oxide, 293, 295, 850 Structural formulas, 57 condensed, 1045, 1047, 1048 Structural isomers, 70, 1014–15 of alkanes, 1045–46 of butene, 1051 Structure, atomic See Atomic structure; Electronic structure Structure, chemical, acid-base equilibria and, 705–10 binary acids, 706 carboxylic acids, 709–10 factors affecting acid strength, 705–6 oxyacids, 707–8 Styrene, 114, 115, 799–800 global demand for, 799 manufacture of, 799–800 Subatomic particles, 43 Subcritical mass, 933 Sublimation, 457–58 heat of, 458 Sublimation curve, 465 Submicroscopic realm, Subscript coefficient vs., 83 in formulas, 82, 89 Subshell(s), 229, 230 of hydrogen atom, 230 Substance, 7, 11 SI unit for amount of, 15 Substitutional alloys, 492–94 Substitution reactions, 1057–58 Substrates, 611 Subtraction, significant figures and, 25 Sucrose, 1074–75 conductivity of solution of, 124, 125 dehydration of, 972 properties of, 502 reactions in dilute acid solutions, 621 reaction with sulfuric acid, 972 standard enthalpy of formation for, 190 van’t Hoff factor for, 552 Sugar, 1075 density of, 20 invert, 1075 Sugarcane, bioethanol from, 199 Sulfate ion, 64, 65, 66, 973 Sulfates, 973 in seawater, 792 Sulfide ions, 66, 761 Sulfides, 278, 284, 971 acid-insoluble, 762 base-insoluble, 762 Sulfites, 972 Sulfur (S), 8, 276, 280, 283, 284, 494, 505, 513, 970–71 elemental, 284, 386 Lewis symbol for, 300 occurrences and production of, 970–71 oxides, oxyacids, and oxyanions of, 971–73 properties and uses of, 283, 971 Sulfur compounds, in troposphere, 784–86 Sulfur dioxide, 277, 284, 400, 777, 784, 850, 968, 971 in atmosphere, 777 dissolved in water, 968 as pollutant, 784 reaction with O2 or O3, 784 Sulfuric acid, 134, 707, 784, 967, 971 acid-dissociation constant of, 694 commercial, 972 formula weight of, 90 reaction with sucrose, 972 sale of, Sulfurous acid, acid-dissociation constant of, 694 Sulfur oxides, 971 Sulfur tetrafluoride, 396 Sun, as energy source, 908 Superconductors, 493 Supercooling, 459–60 Supercritical fluid, 461, 464, 466 Supercritical fluid extraction, 461 Supercritical fluid solvents, 800 Supercritical mass, 933 Supercritical water, 800 Superhydrophobic surfaces, 442 Supernova explosion, 939 Superoxide ion, 279, 393 Superoxides, 969 Supersaturated solutions, 537 Surface tension, 456 Surfactants, 1043 Surroundings, 169 entropy changes in, 830–31 Symbols, chemical, Synchrotron, 918 Syndiotactic polypropylene, 529 Synthetic diamond, 981 Syringes, 19 Système International d’Unités See SI units Systolic pressure, 404 Szilard, Leo, 934 Table salt See Sodium chloride Talc, 985 Tartaric acid, 162, 719 acid-dissociation constant of, 694 Taste, 670, 672 Tausonite, 524 Technetium–99, 928, 950 Technetium (Tc), 258 Teflon (polytetrafluoroethylene), 528, 800, 964 Tellurium (Te), 283, 284, 970–71 Temperature absolute, 419, 596 of atmosphere, 776 body, 164, 186–87 changes, pressure and, 411 critical, 460–61 Curie, 1002, 1035 determining effect on spontaneity, 837–38 of Earth’s surface, 782, 789 entropy and, 828 equilibria and, 654–57 fusion and, 937–38 Gibbs free energy and, 836–38 kinetic energy and, 596 Le Châtelier’s principles and, 651 molality and, 546 molecular speeds and, 419–20 Néel, 1002 reaction rates and, 576, 593–99 activation energy, 594– 95, 597–99 Arrhenius equation for, 596 collision model of, 594 orientation factor in, 594 real vs ideal gas behavior and, 427, 428 regulation in humans, 186–87 of seawater, 792–93 climate change and, 808 SI units of, 15, 17–18 solubility and, 537, 543 spontaneity of reaction and, 815, 837–38 spontaneous processes and, 815 vapor pressure and, 462–63 volume and, 406 Tentative explanation (hypothesis), 15 Tera prefix, 16 Terephthalic acid, 800 Termolecular reactions, 599 tert-Butyl group, 1047 Tertiary structure, of proteins, 1071–72 Tetraboric acid, 988 Tetracene, 397 2,2,3,3-Tetrachlorobutane, 1054 Tetraethyl lead, 1050 Tetragonal lattice, 527 Index body-centered, 527 face-centered, 527 Tetrahedral complexes, 1026–30 Tetrahedral geometry, 344, 345, 346, 347, 348, 349, 351, 355, 357, 1007, 1042 Tetrahydrofuran (THF), 1061 tetra- prefix, 68 Thallium–201, 928 Thallium (Tl), electron configuration of, 241, 245 Theoretical yields, 109–10 Theory, defined, 15 Therapeutic index, 21 Thermal conductivity, 487, 495, 497, 517 of graphene, 517 of metals, 487, 495 Thermal energy, 168 Thermite reaction, 174, 207, 948 Thermochemical equations, 179 guidelines for using, 180 Thermochemistry, 164–211 calorimetry, 181–87 bomb (constant-volume), 185–86 constant-pressure, 183–84 heat capacity and specific heat, 181–83 defined, 166 energy and, 166–70 fossil fuels, 197, 198 kinetic and potential, 166–68 nuclear, 198 solar, 164, 198–99 system and surroundings, 169 transferring, 169–70 units of, 168–69 enthalpy(ies), 175–79 defined, 175 of formation, 189–94 of reaction, 179–81 spontaneous processes and, 181 of vaporization, 189 first law of thermodynamics, 170–75 algebraic expression of, 172 endothermic and exothermic processes, 173–74 heat and work related to internal energy changes, 172–73 internal energy, 171–72 state functions, 174–75 of foods, 194–96 of fuels, 197, 198–99 Hess’s law, 187–89 Thermodynamic equilibrium constant, 636–37 Thermodynamics, 166, 812–55 defined, 814 entropy, 818–20 absolute, 828 Boltzmann’s equation, 823–24 changes in chemical reactions, 828–31 changes in surroundings, 830–31 of expansion, 820 expansion of a gas at molecular level, 821–22 heat transfer and temperature related to, 818–19 and human society, 828 life and, 828 making qualitative predictions about change in, 825–27 microstates and, 823–24 molecular interpretation of, 821–27 molecular motions and energy, 824–25 phase changes and change in, 819–20 predicting relative, 827 probability and, 822 in reactions, 828–31 relationship between heat and, 818–19 temperature and, 828 first law of, 170–75 algebraic expression of, 172 endothermic and exothermic processes, 173–74 heat and work related to internal energy changes, 172–73 internal energy, 171–72 state functions, 174–75 free energy and temperature, 836–38 Gibbs free energy, 831–36 equilibrium constant and, 838–43 under nonstandard conditions, 838–40 relationship between equilibrium constant, K and change in, 840–41 spontaneity and, 832 standard free energies of formation, 834–35 temperature and, 836–38 second law of, 820–21 spontaneous processes, 814–18 identifying, 815–16 pressure and, 815 reversible and irreversible, 816–18 seeking a criterion for spontaneity, 816 temperature and, 815 statistical, 823 third law of, 827 Thermodynamic sign convention, 272n Thermonuclear reactions, 937–38 Thermoplastics, 508 Thermoset See Thermosetting plastics Thermosetting plastics, 508–9 Thermosphere, 776 THF (tetrahydrofuran), 1061 Thiosulfate ion, 973 Third law of thermodynamics, 827 THMs (trihalomethanes), 797–98, 807 Thomson, J J., 43, 45, 46 Thomson,William (Lord Kelvin), 406 Thorium–232, 938 Thorium–234, 911 Threonine, 1069 Thymine, 477, 1079, 1080 Thymol blue, 684 Thyroxin, 964 Tiling, of unit cells, 484 Time reaction rates and, 577, 580, 587–93 SI unit of, 15 Tin (Sn), 8, 271, 984 bonding between chlorine and, 315 electron affinity of, 272 gray, 504, 527 oxidation in aqueous solution, 144 wavelengths of, 296 white, 527 Tin(II) or stannous ion (Sn2+), 63 Tire gauges, 403 Titan (moon), 418 Titanic, raising the, 906 Titanium dioxide, 386 Titanium tetrachloride, 901 Titration(s), 123, 152–55 acid-base, 738–47 indicators, 744–46 of polyprotic acids, 746–47 strong, 738–40 weak, 740–44 equivalence point of, 152 I-31 TNT (trinitrotoluene), 330, 976 Tokamak, 938 Toluene (methylbenzene), 116, 502, 548, 550, 569, 570, 800, 1056 Tooth decay, 748, 755 Tooth enamel, 748, 755, 772 Torr, 402 Torricelli, Evangelista, 402–3 Trace elements, 61 trans fats, 1076 Transferrin, 1011–12 trans isomers, 1003–4, 1015, 1016 Transition-metal complexes, 1002–7 Transition-metal ions, 306 aqueous solutions of, 1000 Transition-metal oxides, 610 Transition metals, 63, 998–1002 chromium, 1002 compounds of (See Coordination compounds) copper (See Copper (Cu)) electron configurations of, 240, 999–1001 iron (See Iron (Fe)) magnetism, 1001–2 mineral sources of, 998 oxidation states of, 999–1001 physical properties of, 998–99 position in periodic table, 998 radii of, 999 Transition state (activated complex), 595, 600 Translational motion, 824 Transplatin, 394 Transuranium elements, 920 Triazine, 339 Triclinic lattice, 484 Trigonal bipyramidal geometry, 345, 352, 353, 357, 1036 Trigonal planar geometry, 345–46, 347, 348, 350, 357, 366, 1042 Trigonal pyramidal geometry, 345–46, 349, 350 Trihalomethanes (THMs), 797–98, 807 Trimethylamine, 1066 2,2,4-Trimethylpentane, 1050 2,3,4-Trimethylpentane, 208 Trinitroglycerin, 199–200 See also Nitroglycerin Trinitrotoluene (TNT), 330, 976 Trinity test, 934 Triphosphate ion, 1008 Triple-alpha process, 939 Triple bonds, 308, 1042 hybrid orbitals and, 368 length of, 329 I-32 Index Triple point, 465 tri- prefix, 68 Tristearin, 195 Tritium, 74, 957 Tropopause, 776 Troposphere, 776 Troposphere-to-stratosphere diffusion rates, 783 Trouton’s rule, 852 Tryptophan, 1069 T-shaped geometry, 345, 353 Tumor, malignant, 943 Tums, 139 Tungsten, 274, 292 Tungsten carbide, 984 Turnover number, 611 Tyndall effect, 560 Tyrosine, 1069 Uhlenbeck, George, 235 Ultraviolet photoelectron spectroscopy (UPS) See Photoelectron spectroscopy (PES) Uncertainty principle, 225–26 measurement and, 225–26 Uncontaminated rainwater, 784 pH value of, 784 primary source of natural acidity of, 784 UNICEF, 980 Unimolecular reactions, 599 Unit cell(s), 483 and crystal lattices, 483–85 for cubic close-packed metal, 490 filling, 485 for hexagonal close-packed metal, 490 United Nations Children’s Fund (UNICEF), 980 Universe, entropy of, 821, 828 Unpaired electrons, 237, 239 Unsaturated hydrocarbons, 1051 alkenes, 1051–53 alkynes, 1053–54 aromatic, 1044, 1056 Unsaturated solutions, 537 Uracil, 1079 Uranium–233, 932 Uranium–234, 911 Uranium–235, 425, 911, 932–34 Uranium-238, 911, 916, 920, 923, 929, 936–37 abundance of, 938 rate of decay, 920 Uranium (U), 241, 255 isotopes of, 255, 425, 911 Urbain, G., 255 Urea, 195, 624, 1040 Urease, 623 Uric acid, 281 U.S Environmental Protection Agency, 784, 798 U.S Global Climate Change program, 21 Valence band, 504 Valence-bond theory, 358 hybrid orbitals and, 359–65 involving d orbitals, 363, 368 pi bonding and, 366–73 sp, 360–61 sp2 and sp3, 359–65 VSEPR model and, 358, 359, 364 Valence electron configurations, 241, 243, 245 Valence electrons, 239–40, 244–45 bonding and, 300–301 delocalized, 482, 487 effective nuclear charge of, 261–62 less than an octet of, 323–24 more than an octet of, 324–25 Valence orbitals, 256 Valence-shell electron-pair repulsion (VSEPR) model, 347–56 basis of, 347 for larger molecules, 355–56 for molecules with expanded valence shells, 352–54 nonbonding electrons and multiple bonds, 351–52 valence-bond theory and, 358, 359, 364 Valence shells, molecules with expanded, 352–54 Valine, 1069 Valproic acid, 116 Vanadium, 492 van der Waals, Johannes, 428, 446 van der Waals constants, 429 van der Waals equation, 428–30 van der Waals forces comparison of, 453 dipole-dipole, 446 hydrogen bonding, 449–52 trends in, 449–50 in water, 450, 451–52 ion-dipole, 446 London dispersion, 447–48 van der Waals radius (nonbonding atomic radius), 263 Vanilla, 1062 Vanillin, 119 van’t Hoff factor (i), 552–53, 558–59, 563 Vapor, Vaporization enthalpies of, 189 heat of, 458 Vapor pressure, 461–64 boiling point and, 463 calculation of, 549–50 defined, 548 lowering, 548–51 molecular-level explanation of, 462 volatility, temperature, and, 462–63 Vapor-pressure curve, 465 Vapors, 400 Variables calculations involving many, 410 Vector quantities, 356 Vectors, 483n Vehicles, flex-fuel, 208 Vibrational motion, 824–25 Vinegar, 1062 as household acid, 132 Vinyl alcohol, 355 Vinyl chloride, 964 Viscosity, 455–56 Visible light, 214 color and, 1019–20 Visible spectrum, 1019–20 Vision, chemistry of, 372–73 “Visualizing Concepts” feature, 32 Vitamins B, 539 B6, 566 C (ascorbic acid), 539, 540, 569, 694, 1043 D, 539 E, 539, 566 fat- and water-soluble, 539, 562, 566, 569 K, 539 A (retinol), 539, 540 Volatile components, separating, 550 Volatile liquids, 462 Volatile organic compounds, 800 Volatile substance, 548 Volatility, 462–63 Volcanic glass (obsidian), 483 Volcanoes, 783 Volta, Alessandro, 884 Voltaic (galvanic) cells, 865–68 See also Batteries concentration cells, 882–86 electromotive force (emf) in, 868–76 concentration effects on, 880–86 equilibrium and, 881 oxidizing and reducing agents, 874–76 standard reduction (half-cell) potentials, 869–74 molecular view of electrode process, 897 standard cell potential of, 869, 872 work done by, 879 Volume(s), 175–76 conversions involving, 29–30 equilibria and, 652–54 of gas, 414–15 interconverting molarity, moles, and, 148–49 law of combining, 406 molar, 409 pressure-volume relationship, 404–5 quantity-volume relationship, 406–7 real vs ideal gas behavior and, 427 SI unit of, 19 temperature-volume relationship, 406 Volumetric flasks, 19 VO2 max, 435 von Hevesy, G., 255 Vulcanization, 971 Vulcanization, of natural rubber, 513 Waage, Peter, 633 Washing soda, 116, 982 Wastes nuclear, 936–37 oxygen-demanding, 795 Water, 9, 56 See also Aqueous equilibria; Aqueous solution(s) acidity and, 707 as analogy for electron flow, 868 arsenic in drinking, 163, 545, 980 autoionization of, 678–80 boiling-point elevation of, 553 bonding in, 351 hydrogen bonding, 450, 451–52 chlorination of, 797 chlorine dissolved in, 796 critical temperature and pressure of, 461 density of, 20, 544, 546 desalination of, 795–96 dissolution in, 124, 125–26 of ionic solid, 826 of oxygen, 794–95 of sodium chloride, 533–34, 536, 537 Index of Earth, 791–94 freshwater and groundwater, 792–94 global water cycle, 791 human activities and, 794–98 oceans and seas, 792 salt water, 792 seawater, 753 electrolysis of, endothermic conversion of liquid water into water vapor, 186 evaporation of, 12 forms of, 400 freezing, 181 freezing point of, 181 fresh, 785, 792–94 hard, 162, 805, 807 heating curve for, 459 heavy, 956, 957 H+ ions in, 673 of hydration, 536 ionic compounds in, 125–26 ion product of, 679–80, 700 meniscus, 457 metal ions in, 702–3 molar mass of, 94 molecular compounds in, 126 molecular compounds in water, 126 molecular model of, from oxidation of glucose, 105 phase changes of, 791 phase diagram of, 465–67 physical states of, polarity of, 356–57 properties of, purification, 795–98 desalination, 795–96 municipal treatment, 796–98 quality of, 794–98 human activities and, 794–98 reactions of, 122 with alkali metals, 278–80 ammonia, 675 with anions, 702 with barium oxide, 969 with butyl chloride, 579 with calcium, 282 with calcium hydride, 959 with carbon dioxide, 277 with cations, 702–4 with chlorine, 286 with elemental calcium, 282 with hydrogen chloride, 672 with nitrous acid, 675 softening of, 807 solubilities of ionic compounds in, 543 solubility guidelines for ionic compounds, 129–30 solubility of alcohol in, 539 solubility of gases in, 538, 542, 543 as solvent, 125–26, 644, 724 specific heat of, 182 standard enthalpy of formation for, 190 standard reduction potentials in, 871 strong and weak electrolytes, 126–28 structural formula for, 57 supercritical, 800 surface tension of, 456 treatment of municipal supplies, 796–98 valence bonding in, 362 vapor pressure of, 463, 549 vibrational and rotational motion in, 824 Water freezing, 181 Water gas, 958 Water purification, 795–98 desalination, 795–96 municipal treatment, 796–98 Water quality, 794–98 desalination, 795–96 dissolved oxygen and, 794–95 fracking and, 797 human activities and, 794–98 municipal treatment and, 796–98 Water softening, 807 Water-soluble vitamins, 539, 566, 569 Water vapor climate and, 789 endothermic conversion of liquid water into, 186 standard enthalpy of formation for, 190 Water waves, 214 frequency of, 214 periodic, 214 speed of, 214 Watt (W), 204 Wave behavior of matter, 223–26 Wave functions, 227 Wavelength, 214 Wave mechanics, 226 See also Quantum mechanics Waves electrons as, 224 nodes on, 226, 227 standing, 226, 227 Weak acid(s), 133–34, 676, 677, 686–96 acid-dissociation constant, 686–87, 690–92, 699– 701 common-ion effect on, 726–28 percent ionization of, 689 polyprotic acids, 694–96 Weak acid-strong base titrations, 740–44 Weak base(s), 133–34, 696–99 common-ion effect on, 726–28 titration with strong acid, 745–46 types of, 698–99 Weak electrolytes, 126–28 identifying, 135 Weak-field ligands, 1024 Weak nuclear force, 49 Weather air densities and, 413 gases and, 398, 400 Weather balloon, 404 WebElements (Web site), 32 Weight atomic (See Atomic weights) density vs., 20 molecular (See Molecular weights) Welding, 967 Werner, Alfred, 1003–4, 1037 Werner’s theory, 1003–5 Wet chemical methods, 762 “What’s Ahead” features, 32 White dwarfs, 939 White light, 1020 White phosphorus, 978 Wind energy, 198 Wires, quantum, 515 Wöhler, Friedrich, 1040 Wood, fuel value and I-33 composition of, 197 Wood’s metal, 491 Work, 166, 169 electrical, 178 internal energy change and, 172–73 mechanical, 175, 178 pressure-volume (mechanical work), 175–77, 178 sign conventions for, 172, 173 transferring energy and, 169–70 Work function, 217 World Health Organization, 798 World ocean, 792 Xenon (Xe), 286, 287, 777 Xenon compounds, 961 Xenon hexafluoride, 394 Xenon tetrafluoride, 961 X-ray crystallography, 486 X-ray diffraction, 224, 486, 528 X-ray diffractometers, 486 X-ray photoelectron spectroscopy (XPS), 297 X-ray photons, 218 X-rays, 215, 218 Yellow brass, 491 Yield actual, 109–10 percent, 109–10 theoretical, 109–10 Yucca Mountain, 937 Zepto prefix, 16 Zero-order reactions, 591 Zeros, significant digits and, 23–24 Zinc (Zn), 240 in cathodic protection, 892 in galvanized iron, 892 oxidation of, 144 reaction with hydrochloric acid, 858 as reducing agent, 874 in solution of Cu2+, 865, 868 Zinc blende (ZnS), 499–500, 505, 525, 527 Zinc ion, 63, 296 Zinc sulfide, 926 Zinn,Walter, 934 Zirconium, 255, 999 Zone refining, 985 UPLOADED BY [STORMRG] Periodic Table of the Elements Main Group Representative Elements 1Aa 1 H 1.00794 2A Li Be 6.941 9.0121831 11 Na 12 Mg 22.989770 24.3050 19 K B 4A 14 C 5A 15 N 10.811 12.0107 14.0067 13 Al 14 Si 15 P 3A 13 Metals Metalloids Nonmetals Transition metals 8B 27 Co 20 Ca 3B 21 Sc 4B 22 Ti 5B 23 V 39.0983 40.078 44.955908 47.867 50.9415 37 Rb 38 Sr 39 Y 40 Zr 41 Nb 42 Mo 43 Tc 44 Ru 45 Rh 46 Pd 85.4678 87.62 88.90584 91.224 92.90637 95.95 [98] 101.07 102.90550 55 Cs 56 Ba 71 Lu 72 Hf 73 Ta 74 W 75 Re 76 Os 77 Ir 6B 24 Cr 7B 25 Mn 26 Fe 51.9961 54.938044 55.845 7A 17 4.002602 O F 10 Ne 15.9994 18.99840316 20.1797 17 Cl 18 Ar 26.981538 28.0855 30.973762 32.065 35.453 39.948 31 Ga 32 Ge 33 As 34 Se 35 Br 36 Kr 65.39 69.723 72.64 74.92160 78.971 79.904 83.80 48 Cd 49 In 50 Sn 51 Sb 52 Te 53 I 54 Xe 107.8682 112.414 114.818 118.710 121.760 127.60 79 Au 80 Hg 81 Tl 82 Pb 83 Bi 84 Po 85 At 86 Rn 2B 12 30 Zn 63.546 47 Ag 106.42 78 Pt 58.933194 58.6934 6A 16 16 S 1B 11 29 Cu 10 28 Ni 8A 18 He 126.90447 131.293 174.967 178.49 180.9479 183.84 186.207 190.23 192.217 204.3833 207.2 208.98038 [208.98] [209.99] [222.02] 87 Fr 88 Ra 103 Lr 104 Rf 105 Db 106 Sg 107 Bh 108 Hs 109 Mt 110 Ds 111 Rg 112 Cn 113 114 Fl 115 116 Lv 117 ** 118 [223.02] [226.03] [262.11] [261.11] [262.11] [266.12] [264.12] [269.13] [268.14] [281.15] [272.15] [285] [284] [289.2] [288] [293] [294] [294] 57 La 58 Ce 59 Pr 60 Nd 61 Pm 62 Sm 63 Eu 64 Gd 65 Tb 66 Dy 67 Ho 68 Er 69 Tm 70 Yb 144.24 [145] 150.36 151.964 157.25 158.92534 162.50 92 U 93 Np 94 Pu 95 Am 96 Cm 97 Bk 98 Cf 99 Es 100 Fm 101 Md 102 No [244.06] [243.06] [247.07] [247.07] [251.08] [252.08] [257.10] [258.10] [259.10] 132.905453 137.327 Main Group Representative Elements Lanthanide series 138.9055 Actinide series 89 Ac [227.03] a The 140.116 140.90766 90 Th 91 Pa 232.0377 231.03588 238.02891 [237.05] 195.078 196.966569 200.59 164.93033 167.259 168.93422 labels on top (1A, 2A, etc.) are common American usage The labels below these (1, 2, etc.) are those recommended by the International Union of Pure and Applied Chemistry (IUPAC) Except for elements 114 and 116, the names and symbols for elements above 113 have not yet been decided Atomic weights in brackets are the names of the longest-lived or most important isotope of radioactive elements Further information is available at http://www.webelements.com ** Discovered in 2010, element 117 is currently under review by IUPAC 173.04 List of Elements with Their Symbols and Atomic Weights Element Actinium Aluminum Americium Antimony Argon Arsenic Astatine Barium Berkelium Beryllium Bismuth Bohrium Boron Bromine Cadmium Calcium Californium Carbon Cerium Cesium Chlorine Chromium Cobalt Copernicium Copper Curium Darmstadtium Dubnium Dysprosium Einsteinium Erbium Europium Fermium Flerovium Fluorine Francium Gadolinium Gallium Germanium Gold a Symbol Ac Al Am Sb Ar As At Ba Bk Be Bi Bh B Br Cd Ca Cf C Ce Cs Cl Cr Co Cn Cu Cm Ds Db Dy Es Er Eu Fm Fl F Fr Gd Ga Ge Au Atomic Number 89 13 95 51 18 33 85 56 97 83 107 35 48 20 98 58 55 17 24 27 112 29 96 110 105 66 99 68 63 100 114 87 64 31 32 79 Atomic Weight Element Symbol a Hafnium Hf 227.03 26.981538 243.06a 121.760 39.948 74.92160 209.99a 137.327 247.07a 9.012183 208.98038 264.12a 10.81 79.904 112.414 40.078 251.08a 12.0107 140.116 132.905452 35.453 51.9961 58.933194 285 63.546 247.07a 281.15a 262.11a 162.50 252.08a 167.259 151.964 257.10a 289.2a 18.99840316 223.02a 157.25 69.723 72.64 196.966569 Hassium Helium Holmium Hydrogen Indium Iodine Iridium Iron Krypton Lanthanum Lawrencium Lead Lithium Livermorium Lutetium Magnesium Manganese Meitnerium Mendelevium Mercury Molybdenum Neodymium Neon Neptunium Nickel Niobium Nitrogen Nobelium Osmium Oxygen Palladium Phosphorus Platinum Plutonium Polonium Potassium Praseodymium Promethium Protactinium Hs He Ho H In I Ir Fe Kr La Lr Pb Li Lv Lu Mg Mn Mt Md Hg Mo Nd Ne Np Ni Nb N No Os O Pd P Pt Pu Po K Pr Pm Pa Mass of longest-lived or most important isotope Except for elements 114 and 116, the names and symbols for elements above 113 have not yet been decided b Atomic Number 72 108 67 49 53 77 26 36 57 103 82 116 71 12 25 109 101 80 42 60 10 93 28 41 102 76 46 15 78 94 84 19 59 61 91 Atomic Weight 178.49 a 269.13 4.002602a 164.93033 1.00794 114.818 126.90447 192.217 55.845 83.80 138.9055 262.11a 207.2 6.941 293a 174.967 24.3050 54.938044 268.14a 258.10a 200.59 95.95 144.24 20.1797 237.05a 58.6934 92.90637 14.0067 259.10a 190.23 15.9994 106.42 30.973762 195.078 244.06a 208.98a 39.0983 140.90766 145a 231.03588 Atomic Number Element Symbol Radium Ra 88 Radon Rhenium Rhodium Roentgenium Rubidium Ruthenium Rutherfordium Samarium Scandium Seaborgium Selenium Silicon Silver Sodium Strontium Sulfur Tantalum Technetium Tellurium Terbium Thallium Thorium Thulium Tin Titanium Tungsten Uranium Vanadium Xenon Ytterbium Yttrium Zinc Zirconium *b *b *b *b Rn Re Rh Rg Rb Ru Rf Sm Sc Sg Se Si Ag Na Sr S Ta Tc Te Tb Tl Th Tm Sn Ti W U V Xe Yb Y Zn Zr 86 75 45 111 37 44 104 62 21 106 34 14 47 11 38 16 73 43 52 65 81 90 69 50 22 74 92 23 54 70 39 30 40 113 115 117 118 Atomic Weight 226.03a 222.02a 186.207a 102.90550 272.15a 85.4678 101.07 261.11a 150.36 44.955908 266a 78.97 28.0855 107.8682 22.989770 87.62 32.065 180.9479 98a 127.60 158.92534 204.3833 232.0377 168.93422 118.710 47.867 183.84 238.02891 50.9415 131.293 173.04 88.90584 65.39 91.224 284a 288a 294a 294a Common Ions Positive Ions (Cations) 1+ ammonium (NH4+) cesium (Cs+) copper(I) or cuprous (Cu+) hydrogen (H+) lithium (Li+) potassium (K+) silver (Ag+) sodium (Na+) mercury(II) or mercuric (Hg2+) strontium (Sr2+) nickel(II) (Ni2+) tin(II) or stannous (Sn2+) zinc (Zn2+) 2+ barium (Ba2+) cadmium (Cd2+) calcium (Ca2+) chromium(II) or chromous (Cr2+) cobalt(II) or cobaltous (Co2+) copper(II) or cupric (Cu2+) iron(II) or ferrous (Fe2+) lead(II) or plumbous (Pb2+) magnesium (Mg2+) manganese(II) or manganous (Mn2+) mercury(I) or mercurous (Hg22+) Negative Ions (Anions) 1acetate (CH3COO- or C2H3O2-) bromide (Br-) chlorate (ClO3-) chloride (Cl-) cyanide (CN-) dihydrogen phosphate (H2PO4-) fluoride (F -) hydride (H-) hydrogen carbonate or bicarbonate (HCO3-) 3+ aluminum (Al3+) chromium(III) or chromic (Cr3+) iron(III) or ferric (Fe3+) hydrogen sulfite or bisulfite (HSO3-) hydroxide (OH-) iodide (I-) nitrate (NO3-) nitrite (NO2-) perchlorate (ClO4-) permanganate (MnO4-) thiocyanate (SCN-) 2carbonate (CO32-) chromate (CrO42-) dichromate (Cr2O72-) hydrogen phosphate (HPO42-) oxide (O2-) peroxide (O22-) sulfate (SO42-) sulfide (S2-) sulfite (SO32-) 3arsenate (AsO43-) phosphate (PO43-) Fundamental Constants* Atomic mass unit Avogadro’s number† Boltzmann Constant Electron charge Faraday constant Gas constant amu lg NA k e F R Mass of electron me Mass of neutron mn Mass of proton mp Pi Planck constant Speed of light in vacuum p h c = = = = = = = = = = = = = = = = = 1.660538921 * 10-27kg 6.02214165 * 1023 amu 6.02214129 * 1023/mol 1.3806488 * 10-23J/K 1.602176565 * 10-19 C 9.64853365 * 104 C/mol 0.0820582 L-atm/mol-K 8.3144621 J/mol-K 5.4857990946 * 10-4 amu 9.10938291 * 10-31 kg 1.008664916 amu 1.674927351 * 10-27 kg 1.007276466 amu 1.672621777 * 10-27 kg 3.1415927 6.62606957 * 10-34 J-s 2.99792458 * 108 m/s *Fundamental constants are listed at the National Institute of Standards and Technology (NIST) Web site: http://physics.nist.gov/cuu/Constants/index.html † Avogadro’s number is also referred to as the Avogadro constant The latter term is the name adopted by agencies such as the International Union of Pure and Applied Chemistry (IUPAC) and the National Institute of Standards and Technology (NIST), but “Avogadro’s number” remains in widespread usage and is used in most places in this book Useful Conversion Factors and Relationships Length Energy (derived) SI unit: meter (m) km = 0.62137 mi mi = 5280 ft = 1.6093 km m = 1.0936 yd in = 2.54 cm (exactly) cm = 0.39370 in Å = 10-10 m SI unit: Joule (J) 1J = = = cal = l eV = Pressure (derived) SI unit: Pascal (Pa) Pa = = atm = = = bar = torr = Mass SI unit: kilogram (kg) kg = lb = = amu = kg-m2/s2 0.2390 cal 1C-V 4.184 J 1.602 * 10-19J 2.2046 lb 453.59 g 16 oz 1.660538921 * 10-27 kg N/m2 kg/m-s2 1.01325 * 105Pa 760 torr 14.70 lb/in2 105 Pa mm Hg Temperature Volume (derived) SI unit: Kelvin (K) K = -273.15 °C = -459.67 °F K = °C + 273.15 °C = -95 (°F - 32°) °F = -59 °C + 32° SI unit: cubic meter (m3) L = 10-3 m3 = dm3 = 103 cm3 = 1.0567 qt gal = qt = 3.7854 L cm3 = mL in3 = 16.4 cm3 Color Chart for Common Elements Generic metal Ag Silver Au Gold Br Bromine C Carbon Ca Calcium Cl Chlorine Cu Copper F Fluorine H Hydrogen I Iodine K Potassium Mg Magnesium N Nitrogen Na Sodium O Oxygen P Phosphorus S Sulfur Si Silicon ... O21g2 (d) C1s2 + H21g2 ∆ CH41g2 (e) HCl1aq2 + O21g2 ∆ H2O 1l2 + Cl21g2 (f) C8H18 1l2 + 25 O21g2 ∆ 16 CO21g2 + 18 H2O1g2 (g) C8H18 1l2 + 25 O21g2 ∆ 16 CO21g2 + 18 H2O 1l2 15.17 When the following reactions... O21g2 ∆ Cl21g2 + H2O1g2? (b) What is the value of Kp for the reaction Cl21g2 + H2O1g2 ∆ HCl1g2 + 12 O21g2? (c) What is the value of Kc for the reaction in part (b)? 15 .27 The following equilibria... Bromthymol blue Phenolphthalein Alizarin yellow R Methyl red Yellow Red pH range for color change 10 12 14 Violet Yellow Red Yellow Blue Yellow Red Yellow Yellow Blue Colorless Pink Yellow Red ▲ Figure