Preview Introduction to General, Organic, and Biochemistry by Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres (2015)

Preview Introduction to General, Organic, and Biochemistry by Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres (2015) Preview Introduction to General, Organic, and Biochemistry by Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres (2015) Preview Introduction to General, Organic, and Biochemistry by Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres (2015) Preview Introduction to General, Organic, and Biochemistry by Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres (2015) Preview Introduction to General, Organic, and Biochemistry by Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres (2015)

Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it H 9.0122 Magnesium 12 24.3050 6.941 Sodium 11 22.9898 Mg 3B (3) 4B (4) 5B (5) 6B (6) NONMETALS METALLOIDS METALS 7B (7) Ca 40.078 Sc 44.9559 Ra 180.9488 Ta 183.84 W 186.207 Re Rf (261.11) Actinides Lanthanides Ac Co Db Ni Sg Bh (262.12) (265) Hs (266) Mt (271) Ds Nd Pm Sm Eu Pa Np 93 Pu 94 Am 95 238.0289 (237.0482) (244.664) (243.061) U 92 231.0388 151.965 63 232.0381 150.36 62 91 (144.91) 61 Protactinium Uranium Neptunium Plutonium Americium 144.24 60 Thorium 90 Pr 59 140.9076 Th Cu Ag Au (272) Rg 196.9666 Gold 79 107.8682 Silver 47 63.546 Copper 29 1B (11) Gd Cm (247.07) Curium 96 157.25 64 Praseodymium Neodymium Promethium Samarium Europium Gadolinium (263.12) Pt 195.084 Platinum 78 106.42 Pd 58.6934 140.115 Ce Cerium 58 (262.11) Ir 192.22 Iridium 77 102.9055 Rh 58.9332 Nickel 28 (10) Zn Cd Hg Tb (247.07) Bk 12.011 10.811 Al Ga In Tl Si Ge Sn Pb Fl (289) Flerovium 114 207.2 Lead 82 118.710 Tin 50 72.61 Germanium 32 28.0855 Silicon 14 Dy (251.08) Cf 162.50 66 Ho (252.08) Es 164.9303 67 Dysprosium Holmium 2004 Discovered — 113 — 204.3833 Thallium 81 114.818 Indium 49 69.723 Gallium 31 26.9815 Aluminum 13 C Carbon Boron B 4A (14) 3A (13) N P As Bi Er (257.10) Fm 167.26 Erbium 68 2004 Discovered — 115 — 208.9804 Bismuth 83 121.760 Sb O S Se Po Tm (258.10) Md 168.9342 Thulium 69 (293) Lv 116 Livermorium (208.98) Polonium 84 127.60 Te 78.96 Selenium 34 32.066 Sulfur 16 15.9994 Oxygen 6A (16) Antimony Tellurium 51 52 74.9216 Arsenic 33 30.9738 Phosphorus 15 14.0067 Nitrogen 5A (15) F Cl Br I At (259.10) No 173.54 Yb He Ne Ar Kr Xe Rn (262.11) Lr 174.9668 Lu 2006 Discovered — 118 — (222.02) Radon 86 131.29 Xenon 54 83.80 Krypton 36 39.948 Argon 18 20.1797 Neon 10 4.0026 Ytterbium Lutetium 70 71 (292) — 117 — (209.99) Astatine 85 126.9045 Iodine 53 79.904 Bromine 35 35.4527 Chlorine 17 18.9984 Fluorine 7A (17) Helium 8A (18) Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium 102 100 97 98 99 101 103 158.9253 Terbium 65 (285) Cn 200.59 Mercury 80 112.411 Cadmium 48 65.38 Zinc 30 2B (12) Hassium Meitnerium Darmstadtium Roentgenium Copernicium 109 110 111 108 112 190.2 Os (226.0254) (227.0278) Fr Hf 178.49 Actinium Rutherfordium Dubnium Seaborgium Bohrium 89 104 106 105 107 138.9055 La (223.02) Ba Radium 88 Cs Francium 87 Ru 137.327 Tc 132.9054 95.96 Osmium 76 92.9064 Mo Fe 55.845 Barium Lanthanum Hafnium Tantalum Tungsten Rhenium 75 73 57 56 72 74 91.224 Nb Mn 54.9380 Cobalt 27 (9) 8B Atomic weight Symbol Atomic number Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium 45 41 44 42 43 46 40 Zr Cr 51.9961 Cesium 55 Y 88.9059 V 50.9415 Iron 26 (8) 101.07 Sr 87.62 Ti 47.867 U 238.0289 Uranium 92 (97.907) 85.4678 Rb Rubidium Strontium Yttrium 39 37 38 39.0983 K Potassium Calcium Scandium Titanium Vanadium Chromium Manganese 21 19 20 24 25 22 23 Na Be Beryllium Lithium Li 2A (2) 1A (1) 1.0079 Hydrogen Note: Atomic masses are 2007 IUPAC values (up to four decimal places) Numbers in parentheses are atomic masses or mass numbers of the most stable isotope of an element Group number, U.S system Group number, IUPAC system Period number STANDARD ATOMIC WEIGHTS OF THE ELEMENTS 2010  Based on relative atomic mass of 12C 12, where 12C is a neutral atom in its nuclear and electronic ground state.† Name Actinium* Aluminum Americium* Antimony Argon Arsenic Astatine* Barium Berkelium* Beryllium Bismuth Bohrium Boron Bromine Cadmium Cesium Calcium Californium* Carbon Cerium Chlorine Chromium Cobalt Copernicium* Copper Curium* Darmstadtium Dubnium Dysprosium Einsteinium* Erbium Europium Fermium* Fluorine Francium* Gadolinium Gallium Germanium Gold Hafnium Hassium Helium Holmium Hydrogen Indium Iodine Iridium Iron Krypton Lanthanum Lawrencium* Lead Lithium Lutetium Magnesium Manganese Meitnerium Mendelevium* Mercury Symbol Atomic Number Atomic Weight Ac Al Am Sb Ar As At Ba Bk Be Bi Bh B Br Cd Cs Ca Cf C Ce Cl Cr Co Cn Cu Cm Ds Db Dy Es Er Eu Fm F Fr Gd Ga Ge Au Hf Hs He Ho H In I Ir Fe Kr La Lr Pb Li Lu Mg Mn Mt 89 13 95 51 18 33 85 56 97 83 107 35 48 55 20 98 58 17 24 27 112 29 96 110 105 66 99 68 63 100 87 64 31 32 79 72 108 67 49 53 77 26 36 57 103 82 71 12 25 109 (227) 26.9815386(8) (243) 121.760(1) 39.948(1) 74.92160(2) (210) 137.327(7) (247) 9.012182(3) 208.98040(1) (264) 10.811(7) 79.904(1) 112.411(8) 132.9054519(2) 40.078(4) (251) 12.0107(8) 140.116(1) 35.453(2) 51.9961(6) 58.933195(5) (285) 63.546(3) (247) (271) (262) 162.500(1) (252) 167.259(3) 151.964(1) (257) 18.9984032(5) (223) 157.25(3) 69.723(1) 72.64(1) 196.966569(4) 178.49(2) (277) 4.002602(2) 164.93032(2) 1.00794(7) 114.818(3) 126.90447(3) 192.217(3) 55.845(2) 83.798(2) 138.90547(7) (262) 207.2(1) 6.941(2) 174.9668(1) 24.3050(6) 54.938045(5) (268) Md Hg 101 80 (258) 200.59(2) †The atomic weights of many elements can vary depending on the origin and treatment of the sample This is particularly true for Li; commercially available lithium-containing materials have Li atomic weights in the range of 6.939 and 6.996 The uncertainties in atomic weight values are given in parentheses following the last significant figure to which they are attributed Name Molybdenum Neodymium Neon Neptunium* Nickel Niobium Nitrogen Nobelium* Osmium Oxygen Palladium Phosphorus Platinum Plutonium* Polonium* Potassium Praseodymium Promethium* Protactinium* Radium* 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 Ununhexium Ununoctium Ununpentium Ununquadium Ununseptium Ununtrium Uranium* Vanadium Xenon Ytterbium Yttrium Zinc Zirconium Symbol Mo Nd Ne Np Ni Nb N No Os O Pd P Pt Pu Po K Pr Pm Pa Ra 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 Uuh Uuo Uup Uuq Uus Uut U V Xe Yb Y Zn Zr Atomic Number Atomic Weight 42 60 10 93 28 41 102 76 46 15 78 94 84 19 59 61 91 88 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 74 116 118 115 114 117 113 92 23 54 70 39 95.96(2) 144.22(3) 20.1797(6) (237) 58.6934(4) 92.90638(2) 14.0067(2) (259) 190.23(3) 15.9994(3) 106.42(1) 30.973762(2) 195.084(9) (244) (209) 39.0983(1) 140.90765(2) (145) 231.03588(2) (226) (222) 186.207(1) 102.90550(2) (272) 85.4678(3) 101.07(2) (261) 150.36(2) 44.955912(6) (266) 78.96(3) 28.0855(3) 107.8682(2) 22.9896928(2) 87.62(1) 32.065(5) 180.9488(2) (98) 127.60(3) 158.92535(2) 204.3833(2) 232.03806(2) 168.93421(2) 118.710(7) 47.867(1) 183.84(1) (292) (294) (228) (289) (292) (284) 238.02891(3) 50.9415(1) 131.293(6) 173.54(5) 88.90585(2) 30 40 65.38(2) 91.224(2) *Elements with no stable nuclide; the value given in parentheses is the atomic mass number of the isotope of longest known half-life However, three such elements (Th, Pa, and U) have a characteristic terrestial isotopic composition, and the atomic weight is tabulated for these http://www chem.qmw.ac.uk/iupac/AtWt/ Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it REASONS to buy your textbooks and course materials at SAVINGS: CHOICE: CONVENIENCE: Prices up to 75% off, daily coupons, and free shipping on orders over $25 Multiple format options including textbook, eBook and eChapter rentals Anytime, anywhere access of eBooks or eChapters via mobile devices SERVICE: STUDY TOOLS: Free eBook access while your text ships, and instant access to online homework products Study tools* for your text, plus writing, research, career and job search resources * availability varies Find your course materials and start saving at: www.cengagebrain.com Source Code: 14M-AA0107 Engaged with you www.cengage.com Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it IntroductIon to General, organic, and Biochemistry ElEvEnth Edition Frederick A Bettelheim William H Brown Beloit College Mary K campbell Mount Holyoke College Shawn o Farrell Olympic Training Center omar J torres Santa Ana College Australia • Brazil • Mexico • Singapore • United Kingdom • United States Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it This is an electronic version of the print textbook Due to electronic rights restrictions, some third party content may be suppressed Editorial review has deemed that any suppressed content does not materially affect the overall learning experience The publisher reserves the right to remove content from this title at any time if subsequent rights restrictions require it For valuable information on pricing, previous editions, changes to current editions, and alternate formats, please visit www.cengage.com/highered to search by ISBN#, author, title, or keyword for materials in your areas of interest Important Notice: Media content referenced within the product description or the product text may not be available in the eBook version Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it Introduction to General, Organic, and Biochemistry, Eleventh Edition Frederick A Bettelheim, William H Brown, Mary K Campbell, Shawn O Farrell, Omar J Torres Product Director: Mary Finch Product Manager: Maureen Rosener Content Developer: Alyssa White Product Assistant: Christopher Robinson Media Developer: Brendan Killion Marketing Manager: Julie Schuster Content Project Manager: Teresa L Trego Art Director: Maria Epes Manufacturing Planner: Judy Inouye © 2016, 2013 Cengage Learning WCN: 02-200-203 ALL RIGHTS RESERVED No part of this work covered by the copyright herein may be reproduced, transmitted, stored, or used in any form or by any means graphic, electronic, or mechanical, including but not limited to photocopying, recording, scanning, digitizing, taping, Web distribution, information networks, or information storage and retrieval systems, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the publisher For product information and technology assistance, contact us at Cengage Learning Customer & Sales Support, 1-800-354-9706 For permission to use material from this text or product, submit all requests online at www.cengage.com/permissions Further permissions questions can be e-mailed to permissionrequest@cengage.com Production Service: Graphic World Inc Photo Researcher: PreMedia Global Library of Congress Control Number: 2014948100 Text Researcher: PreMedia Global ISBN-13: 978-1-285-86975-9 Copy Editor: Graphic World Inc ISBN-10: 1-285-86975-3 Text Designer: Diane Beasley Cover Designer: Kathleen Cunningham Cover Image: Seth Joel/Photodisc/Getty Images Compositor: Graphic World Inc Cengage Learning 20 Channel Center Street Boston, MA 02210 USA Cengage Learning is a leading provider of customized learning solutions with office locations around the globe, including Singapore, the United Kingdom, Australia, Mexico, Brazil, and Japan Locate your local office at www.cengage.com/global Cengage Learning products are represented in Canada by Nelson Education, Ltd To learn more about Cengage Learning Solutions, visit www.cengage.com Purchase any of our products at your local college store or at our preferred online store www.cengagebrain.com Printed in the United States of America Print Number: 01 Print Year: 2014 Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it To Carolyn, with whom life is a joy —WB To my family and friends – thank you for all your support I couldn’t have done it without you — MC To my lovely wife, Courtney – between textbook revisions, a full-time job, and school, I have been little more than a ghost around the house, hiding in my study writing Courtney held the family together, taking care of our children and our home while maintaining her own writing schedule None of this would have been possible without her love, support, and tireless effort —SF To my loving family and friends who have supported me through this journey: Mom, Dad, Lisa, Abuela, René, Ryan, and Dianne I could not have made it without your urging and support I am truly blessed to have each of you in my life — OT Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it Contents in Brief General chemistry chapter Matter, Energy, and Measurement chapter Atoms chapter Chemical Bonds chapter Chemical Reactions chapter Gases, liquids, and Solids chapter Solutions and Colloids chapter Reaction Rates and Chemical Equilibrium chapter Acids and Bases chapter nuclear Chemistry 27 58 91 117 147 175 200 233 organic chemistry chapter 10 organic Chemistry chapter 11 Alkanes 260 273 chapter 12 Alkenes and Alkynes 298 chapter 13 Benzene and its derivatives 322 chapter 14 Alcohols, Ethers, and thiols 338 chapter 15 Chirality: the handedness of Molecules chapter 16 Amines 358 376 chapter 17 Aldehydes and Ketones chapter 18 Carboxylic Acids 389 404 chapter 19 Carboxylic Anhydrides, Esters, and Amides 423 iv Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it 166 Chapter Solutions and Colloids ChemiCAl ConneCtions 6e emulsions and emulsifying Agents Oil and water not mix Even when we stir them vigorously and the oil droplets become dispersed in the water, the two phases separate as soon as we stop stirring There are, however, a number of stable colloidal systems made of oil and water, known as emulsions For example, the oil droplets in milk are dispersed in an aqueous solution This is possible because milk contains a protective colloid—the milk protein called casein Casein molecules surround the oil droplets, and because they are polar and carry a charge, they protect and stabilize the oil droplets Casein is thus an emulsifying agent Another emulsifying agent is egg yolk This ingredient in mayonnaise coats the oil droplets and prevents them from separating test your knowledge with Problem 6-86 So why colloidal particles remain in solution despite all the collisions due to their Brownian motion? Two reasons explain this phenomenon: Emulsions Systems, such as fats in milk, consisting of a liquid with or without an emulsifying agent in an immiscible liquid, usually as droplets of larger than colloidal size ▲ Freshly made wines are often cloudy because of colloidal particles (left) Removing the particles clarifies the wine (right) Colligative property A property of a solution that depends only on the number of solute particles and not on the chemical identity of the solute Thus, the combined effects of the solvation layer and the surface charge keep colloidal particles in a stable dispersion By taking advantage of these effects, chemists can either increase or decrease the stability of a colloidal system If we want to get rid of a colloidal dispersion, we can remove the solvation layer, the surface charge, or both For example, proteins in the blood form a colloidal dispersion If we want to isolate a protein from blood, we may want to precipitate it We can accomplish this task in two ways: by removing the hydration layer or by removing the surface charges If we add a solvent such as ethanol or acetone, each of which has great affinity for water, water is removed from the solvation layer of the protein, and when unprotected protein molecules collide, they stick together and form sediment Similarly, by adding an electrolyte such as NaCl to the solution, we can remove the charges from the surface of the proteins (by a mechanism too complicated to discuss here) Without their protective charges, two protein molecules will no longer repel each other Instead, when they collide, they stick together and precipitate from the solution ▲ NALCO Chemical Company Most colloidal particles carry a large solvation layer If the solvent is water, as in the case of protein molecules in the blood, the colloidal particles are surrounded by a large number of water molecules, which move together with the colloidal particles and cushion them When two colloidal particles collide as a result of Brownian motion, they not actually touch each other; instead, only their solvent layers collide As a consequence, the particles not stick together and precipitate Instead, they stay in solution The large surface area of colloidal particles acquires charges from the solution All colloids in a particular solution acquire the same kind of charge—for example, a negative charge This development leaves a net negative charge in the solvent When a charged colloidal particle encounters another charged colloidal particle, the two repel each other because of their like charges 6-8 What Is a Colligative Property? A colligative property is any property of a solution that depends only on the number of solute particles dissolved in the solvent and not on the nature of the solute particles Several colligative properties exist, including Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it 6-8 What Is a Colligative Property? 167 freezing-point depression, boiling-point elevation, and osmotic pressure Of these three, osmotic pressure is of paramount importance in biological systems A Freezing-Point Depression One mole of any particle, whether it is a molecule or ion, dissolved in 1000 g of water lowers the freezing point of the water by 1.86°C The nature of the solute does not matter, only the number of particles DTf Freezing-point depression The decrease in the freezing point of a liquid caused by adding a solute 21.86°C mol of particles mol Charles D Winters ▲ This principle is used in a number of practical ways In winter, we use salts (sodium chloride and calcium chloride) to melt snow and ice on our streets The salts dissolve in the melting snow and ice, which lowers the freezing point of the water Another application is the use of antifreeze in automobile radiators Because water expands upon freezing (see Chemical Connections 5D), the ice formed in a car’s cooling system when the outside temperature falls below 0°C can crack the engine block The addition of antifreeze prevents this problem, because it makes the water freeze at a much lower temperature The most common automotive antifreeze is ethylene glycol, C2H6O2 ▲ Salting lowers the freezing point of ice eXAmPle 6-10 Freezing-Point Depression If we add 275 g of ethylene glycol, C2H6O2, a nondissociating molecular compound, per 1000 g of water in a car radiator, what will be the freezing point of this solution? strategy We are given 275 g of ethylene glycol (molar mass 62.1 g) per 1000 g water and asked to calculate the freezing point of the solution We first calculate the moles of ethylene glycol present in the solution and then the freezing-point depression caused by that number of moles solution DT 275 g C2H6O2 mol C2H6O2 21.86°C 28.24°C 62.1 g C2H6O2 mol C2H6O2 The freezing point of the water will be lowered from 0°C to 28.24°C, and the radiator will not crack if the outside temperature remains above 28.24°C 17.17°F Problem 6-10 If we add 215 g of methanol, CH3OH, to 1000 g of water, what will be the freezing point of the solution? If a solute is ionic, then each mole of solute dissociates to more than one mole of particles For example, if we dissolve one mole (58.5 g) of NaCl in 1000 g of water, the solution contains two moles of solute particles: one mole each of Na1 and Cl2 The freezing point of water will be lowered by twice 1.86°C, that is, by 3.72°C per mole of NaCl Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it 168 Chapter Solutions and Colloids eXAmPle 6-11 Freezing-Point Depression What will be the freezing point of the resulting solution if we dissolve one mole of potassium sulfate, K2SO4, in 1000 g of water? strategy and solution One mole of K2SO4 dissociates to produce three moles of ions: two moles of K1 and one mole of SO422 The freezing point will be lowered by 3 1.86°C 5.58°C, and the solution will freeze at 25.58°C Problem 6-11 Which aqueous solution would have the lowest freezing point? (a) 6.2 M NaCl (b) 2.1 M Al(NO3)3 (c) 4.3 M K2SO3 B Boiling-Point elevation The boiling point of a substance is the temperature at which the vapor pressure of the substance equals atmospheric pressure A solution containing a nonvolatile solute has a lower vapor pressure than the pure solvent and must be at a higher temperature before its vapor pressure equals atmospheric pressure and it boils Thus, the boiling point of a solution containing a nonvolatile solute is higher than that of the pure solvent One mole of any molecule or ion dissolved in 1000 g of water raises the boiling point of the water by 0.512°C The nature of the solute does not matter, only the number of particles DTb 0.512°C mol of particles mol eXAmPle 6-12 Boiling-Point elevation Calculate the boiling point of a solution prepared by dissolving 275 g of ethylene glycol (C2H6O2) in 1000 mL of water strategy To calculate the boiling point elevation, we must determine the number of moles of ethylene glycol dissolved in 1000 mL of water We use the conversion factor 1.00 mole of ethylene glycol 62.1 g of ethylene glycol solution DT 275 g C2H6O2 mol C2H6O2 0.512°C 2.27°C 62.1 g C2H6O2 mol C2H6O2 The boiling point is raised by 2.27°C Therefore, the solution boils at 102.3°C Problem 6-12 Calculate the boiling point of a solution prepared by dissolving 310 g of ethanol, CH3CH2OH, in 1000 mL of water C osmotic Pressure To understand osmotic pressure, let us consider the experimental setup shown in Figure 6-15 Suspended in the beaker is a bag containing a 5% solution of sugar in water The bag is made of a semipermeable membrane Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it 6-8 What Is a Colligative Property? 169 Net flow of water will continue until the pressure exerted by solution in the tube is large enough to equalize rates of passage of water molecules in both directions through the semipermeable material Height of solution column Glass tube The height of the column of solution is a measure of the osmotic pressure, P Water flows through the walls of the bag from a region of pure water The bag is made of semipermeable material that allows water molecules but not sugar molecules to pass through Pure water 5% sugar 95% water (a) …to one of higher solute concentration (the sugar solution) (b) Figure 6-15 Demonstration of osmotic pressure that contains very tiny pores, far too small for us to see but large enough to allow solvent (water) molecules to pass through them but not the larger solvated sugar molecules When the bag is submerged in pure water, Figure 6-15(a), water flows into the bag by osmosis and raises the liquid level in the tube attached to the bag, Figure 6-15(b) Although sugar molecules are too big to pass through the membrane, water molecules easily move back and forth across it However, this process cannot continue indefinitely because gravity prevents the difference in levels from becoming too great Eventually a dynamic equilibrium is achieved The height of the liquid in the tube remains unchanged and is a measure of osmotic pressure The liquid level in the glass tube and the breaker can be made equal again if we apply an external pressure through the glass tube The amount of external pressure required to equalize the levels is called the osmotic pressure (P) Although this discussion assumes that one compartment contains pure solvent and the other a solution, the same principle applies if both compartments contain solutions, as long as their concentrations are different The solution of higher concentration always has a higher osmotic pressure than the one of lower concentration, which means that the flow of solvent molecules always occurs from the more dilute solution into the more concentrated solution Of course, the number of particles is the most important consideration We must remember that in ionic solutions, each mole of solute gives rise to more than one mole of particles For convenience in calculation, we define a new term, osmolarity, which is molarity (M) of the solution multiplied by the number of particles (i) produced by each formula unit of solute Osmosis The passage of solvent molecules from a less concentrated solution across a semipermeable membrane into a more concentrated solution Osmotic pressure (P) The amount of external pressure that must be applied to the more concentrated solution to stop the passage of solvent molecules across a semipermeable membrane Osmolarity M i Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it 170 Chapter Solutions and Colloids eXAmPle 6-13 osmolarity A 0.89 percent w/v NaCl aqueous solution is referred to as a physiological or isotonic saline solution because it has the same concentration of salts as normal human blood Although blood contains several salts, saline solution has only NaCl What is the osmolarity of this solution? strategy We are given a 0.89% solution—that is, a solution that contains 0.89 g NaCl per 100 mL of solution Because osmolarity is based on grams of solute per 1000 grams of solution, we calculate that this solution contains 8.9 g of NaCl per 1000 g of solution Given this concentration, we can then calculate the molarity of the solution solution 0.89 g NaCl 0.15 mol NaCl mol NaCl 1000 mL 5 0.15 M 3 1L 1L 58.4 g NaCl 100 mL Each formula unit of NaCl dissociates into two particles, namely Na and Cl ; therefore, the osmolarity is two times the molarity Osmolarity 0.15 0.30 osmol Problem 6-13 Charles D Winters What is the osmolarity of a 3.3% w/v Na3PO4 solution? Figure 6-16 Osmosis and vegetables As noted earlier, osmotic pressure is a colligative property The osmotic pressure generated by a solution across a semipermeable membrane— the difference between the heights of the two columns in Figure 6-15(b)— depends on the osmolarity of the solution If the osmolarity increases by a factor of 2, the osmotic pressure will also increase by a factor of Osmotic pressure is very important in biological organisms because cell membranes are semipermeable For example, red blood cells in the body are suspended in a medium called plasma, which must have the same osmolarity as the red blood cells Two solutions with the same osmolarity are called isotonic, so plasma is said to be isotonic with red blood cells As a consequence, no osmotic pressure is generated across the cell membrane Cell-shriveling by osmosis occurs when vegetables or meats are cured in brine (a concentrated aqueous solution of NaCl) When a fresh cucumber is soaked in brine, water flows from the cucumber cells into the brine, leaving behind a shriveled cucumber, Figure 6-16 (right) With the proper spices added to the brine, the cucumber becomes a tasty pickle A cucumber soaked in pure water is affected very little, as shown in Figure 6-16 (left) What would happen if we suspended red blood cells in distilled water instead of in plasma? Inside the red blood cells, the osmolarity is approximately the same as in a physiological saline solution—0.30 osmol (an isotonic solution) Distilled water has zero osmolarity As a consequence, water flows into the red blood cells The volume of the cells increases, and they swell, as shown in Figure 6-18(b) The membrane cannot resist the osmotic pressure, and the red blood cells eventually burst, spilling their contents into the water We call this process hemolysis Solutions in which the osmolarity (and hence osmotic pressure) is lower than that of suspended cells are called hypotonic solutions Obviously, it Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it 6-8 What Is a Colligative Property? 171 ChemiCAl ConneCtions 6F In osmosis, the solvent flows spontaneously from the dilute solution compartment into the concentrated solution compartment In reverse osmosis, the opposite happens When we apply pressures greater than the osmotic pressure to the more concentrated solution, solvent flows from it to the more dilute solution by a process we call reverse osmosis (Figure 6-17) Reverse osmosis is used to make drinkable water from seawater or brackish water In large plants in the Persian Gulf countries, for example, more than 100 atm pressure is applied to seawater containing 35,000 ppm salt The water that passes through the semipermeable membrane under this pressure contains only 400 ppm salt—well within the limits set by the World Health Organization for drinkable water An emergency hand-operated water desalinator that works by reverse osmosis It can produce 4.5 L of pure water per hour from seawater, which can save someone adrift at sea Courtesy of Katadyn Reverse osmosis and Desalinization Applied pressure Osmotic pressure (P) Brine Water Semipermeable membrane (a) Water molecules pass through the semipermeable membrane to dilute the brine solution… (b) …until the height of the solution creates sufficient pressure to stop the net flow Piston Reverse osmosis is the application of an external pressure in excess of osmotic pressure to force water molecules to the pure water side (c) Figure 6-17 Normal and reverse osmosis Normal osmosis is represented in (a ) and (b ) Reverse osmosis is represented in (c ) test your knowledge with Problems 6-87 and 6-88 Science Source Figure 6-18 Red blood cells in solutions of different osmolarity or tonicity Red blood cells in (a) isotonic, (b) hypotonic, and (c) hypertonic solutions (a) The cells are unaffected (b) The cells swell by hemolysis (c) The cells shrink by crenation Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it Chapter Solutions and Colloids is very important that we always use isotonic solutions and never hypotonic solutions in intravenous feeding and blood transfusion Hypotonic solutions would simply kill the red blood cells by hemolysis Equally important, we should not use hypertonic solutions A hypertonic solution has a greater osmolarity (and greater osmotic pressure) than the red blood cells If red blood cells are placed in a hypertonic solution— for example, 0.5 osmol glucose solution—water flows from the cells into the glucose solution through the semipermeable cell membrane This process, called crenation, shrivels the cells, as shown in Figure 6-18(c) As already mentioned in Example 6-13, 0.89 w/v% NaCl (physiological saline) is isotonic with red blood cells and is used in intravenous injections Charles D Winters ▲ 172 ▲ An isotonic saline solution eXAmPle 6-14 toxicity Is a 0.50% w/v aqueous solution of KCl (a) hypertonic, (b) hypotonic, or (c) isotonic compared to red blood cells? strategy Calculate the osmolarity of the solution, which is its molarity times the number of particles produced by each formula unit of solute solution The 0.50% w/v solution of KCl contains 5.0 g KCl in 1.0 L of solution: 5.0 g KCl 1.0 mol KCl 0.067 mol KCl 0.067 M KCl 1.0 L 1.0 L 74.6 g KCl Because each formula unit of KCl yields two particles, the osmolarity is 0.067 0.13 osmol; this is smaller than the osmolarity of the red blood cells, which is 0.30 osmol Therefore, the KCl solution is hypotonic Problem 6-14 Which solution is isotonic compared to red blood cells? (a) 0.1 M Na2SO4 (b) 1.0 M Na2SO4 (c) 0.2 M Na2SO4 D Dialysis An osmotic semipermeable membrane allows only solvent and not solute molecules to pass If, however, the openings in the membrane are somewhat larger, then small solute molecules can also pass through, but large solute molecules, such as macromolecular and colloidal particles, cannot This process is called dialysis For example, ribonucleic acids are important biological molecules that we will study in Chapter 25 When biochemists prepare ribonucleic acid solutions, they must remove small particles, such as NaCl, from the solution to obtain a pure nucleic acid preparation To so, they place the nucleic acid solution in a dialysis bag (made of cellophane) of sufficient pore size to allow all the small particles to diffuse and retain only the large nucleic acid molecules If the dialysis bag is suspended in flowing distilled water, all NaCl and small particles will leave the bag After a certain amount of time, the bag will contain only the pure nucleic acids dissolved in water Our kidneys work in much the same way The millions of nephrons, or kidney cells, have very large surface areas in which the capillaries of the ▲ Dr P Marazzi/Science Source Dialysis A process in which a solution containing particles of different sizes is placed in a bag made of a semipermeable membrane The bag is placed into a solvent or solution containing only small molecules The solution in the bag reaches equilibrium with the solvent outside, allowing the small molecules to diffuse across the membrane but retaining the large molecules ▲ A portable dialysis unit Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it Summary of Key Questions 173 ChemiCAl ConneCtions 6G hemodialysis The kidneys’ main function is to remove toxic waste products from the blood When the kidneys are not functioning properly, these waste products accumulate and may threaten life Hemodialysis is a process that performs the same filtration function (see the figure) In hemodialysis, the patient’s blood circulates through a long tube of cellophane membrane suspended in an isotonic solution and then returns to the patient’s vein The cellophane membrane retains the large particles (for example, proteins) but allows the small ones, including the toxic wastes, to pass through In this way, dialysis removes wastes from the blood If the cellophane tube were suspended in distilled water, other small molecules, such as glucose, and ions, such as Na and Cl , would also be removed from the blood That is something we don’t want to happen The isotonic solution used in hemodialysis consists of 0.6% NaCl, 0.04%   KCl, 0.2% NaHCO3, and 0.72% glucose (all w/v) It ensures that no glucose or Na is lost from the blood A patient usually remains on an artificial kidney machine for four to seven hours During this time, the isotonic bath is changed every two hours Kidney machines allow people with kidney failure to lead a normal life, although they must take these hemodialysis treatments regularly Blood in Blood in Hollow membrane tubes Dialysate out Jacket Dialysate in Blood out A schematic diagram of the hollow-fiber (or capillary) dialyzer, the most commonly used artificial kidney During dialysis, blood flows through small tubes constructed of a semipermeable membrane; the tubes themselves are bathed in the dialyzing solution test your knowledge with Problems 6-89 and 6-90 blood vessels come in contact with the nephrons The kidneys serve as a gigantic filtering machine The waste products of the blood dialyse out through semipermeable membranes in the glomeruli and enter collecting tubes that carry the urine to the ureter The glomeruli of the kidneys are fine capillary blood vessels in which the body’s waste products are removed from the blood Meanwhile, large protein molecules and cells are retained in the blood summary of Key Questions section 6-1 What Do We Need to Know as We Begin? section 6-2 What Are the Most Common Types of Solutions? • Systems containing more than one component are mixtures • Homogeneous mixtures are uniform throughout • Heterogeneous mixtures exhibit well-defined boundaries between phases • The most common types of solutions are gas in liquid, liquid in liquid, solid in liquid, gas in gas, and solid in solid • When a solution consists of a solid or gas dissolved in a liquid, the liquid acts as the solvent, and the solid or Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it 174 Chapter Solutions and Colloids gas is the solute When one liquid is dissolved in another, the liquid present in greater amount is considered to be the solvent section 6-3 What Are the Distinguishing Characteristics of Solutions? • The distribution of solute particles is uniform throughout • The components of a solution not separate on standing • A solution cannot be separated into its components by filtration • For any given solute and solvent, it is possible to make solutions of many different compositions • Most solutions are transparent section 6-4 What Factors Affect Solubility? • The solubility of a substance is the maximum amount of the substance that dissolves in a given amount of solvent at a given temperature • “Like dissolves like” means that polar molecules are soluble in polar solvents and that nonpolar molecules are soluble in nonpolar solvents The solubility of solids and liquids in liquids usually increases with increasing temperature; the solubility of gases in liquids usually decreases with increasing temperature section 6-5 What Are the Most Common Units for Concentration? • Percent concentration is given in either weight per unit volume of solution (w/v) or volume per unit volume of solution (v/v) • Percent weight/volume (w/v%) is the weight of solute per unit volume of solvent multiplied by 100 • Percent volume/volume (v/v%) is the volume of solute per unit volume of solution multiplied by 100 • Molarity (M) is the number of moles of solute per liter of solution section 6-6 Why Is Water Such a Good Solvent? • Water is the most important solvent, because it dissolves polar compounds and ions through hydrogen bonding and dipole–dipole interactions Hydrated ions are surrounded by water molecules (as a solvation layer) that move together with the ion, cushioning it from collisions with other ions Aqueous solutions of ions and molten salts are electrolytes and conduct electricity section 6-7 What Are Colloids? • Colloids exhibit a chaotic random motion, called Brownian motion Colloids are stable mixtures despite the relatively large size of the colloidal particles (1 to 1000 nm) The stability results from the solvation layer that cushions the colloidal particles from direct collisions and from the electric charge on the surface of colloidal particles section 6-8 What Is a Colligative Property? • A colligative property is a property of a solution that depends only on the number of solute particles present • Freezing-point depression, boiling-point elevation, and osmotic pressure are examples of colligative properties • Osmotic pressure operates across an osmotic semipermeable membrane that allows only solvent molecules to pass but screens out all larger particles In osmotic pressure calculations, concentration is measured in osmolarity, which is the molarity of the solution multiplied by the number of particles produced by dissociation of the solute • Red blood cells in a hypotonic solution swell and burst, a process called hemolysis • Red blood cells in a hypertonic solution shrink, a process called crenation Some semipermeable membranes allow small solute particles to pass through along with solvent molecules • In dialysis, such membranes are used to separate larger particles from smaller ones Problems orange-numbered problems are applied section 6-2 What Are the Most Common Types of Solutions? 6-15 Answer true or false (a) A solute is the substance dissolved in a solvent to form a solution (b) A solvent is the medium in which a solute is dissolved to form a solution (c) Some solutions can be separated into their components by filtration (d) Acid rain is a solution 6-16 Answer true or false (a) Solubility is a physical property like melting point and boiling point (b) All solutions are transparent—that is, you can see through them (c) Most solutions can be separated into their components by physical methods such as distillation and chromatography 6-17 Vinegar is a homogeneous aqueous solution containing 6% acetic acid Which is the solvent? 6-18 Suppose you prepare a solution by dissolving glucose in water Which is the solvent, and which is the solute? 6-19 In each of the following, tell whether the solutes and solvents are gases, liquids, or solids (a) Bronze (see Chemical Connections 2E) (b) Cup of coffee (c) Car exhaust (d) Champagne Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it Problems 6-20 Give a familiar example of solutions of each of these types: (a) Liquid in liquid (b) Solid in liquid (c) Gas in liquid (d) Gas in gas 6-21 Are mixtures of gases true solutions or heterogeneous mixtures? Explain section 6-4 What Factors Affect Solubility? 6-22 Answer true or false (a) Water is a good solvent for ionic compounds because water is a polar liquid (b) Small covalent compounds dissolve in water if they can form hydrogen bonds with water molecules (c) The solubility of ionic compounds in water generally increases as temperature increases (d) The solubility of gases in liquids generally increases as temperature increases (e) Pressure has little effect on the solubility of liquids in liquids (f ) Pressure has a major effect on the solubility of gases in liquids (g) In general, the greater the pressure of a gas over water, the greater the solubility of the gas in water (h) Oxygen, O2, is insoluble in water 6-23 We dissolved 0.32 g of aspartic acid in 115.0 mL of water and obtained a clear solution After it stands for two days at room temperature, we notice a white powder at the bottom of the beaker What may have happened? 6-24 The solubility of a compound is 2.5 g in 100 mL of aqueous solution at 25°C If we put 1.12 g of the compound in a 50.-mL volumetric flask at 25°C and add sufficient water to fill it to the 50.-mL mark, what kind of solution we get—saturated or unsaturated? Explain 6-25 A small amount of solid is added to a separatory funnel containing layers of diethyl ether and water After shaking the separatory funnel, in which layer will we find each of the following solids? (a) NaCl (b) Camphor (C10H16O) (c) KOH 6-26 On the basis of polarity and hydrogen bonding, which solute would be the most soluble in benzene, C6H6? (a) CH3OH (b) H2O (c) CH3CH2CH2CH3 (d) H2SO4 6-27 Suppose that you discover a stain on an oil painting and want to remove it without damaging the painting The stain is not water-insoluble Knowing the polarities of the following solvents, which one would you try first and why? (a) Benzene, C6H6 (b) Isopropyl (rubbing) alcohol, C3H7OH (c) Hexane, C6H14 6-28 Which pairs of liquids are likely to be miscible? (a) H2O and CH3OH (b) H2O and C6H6 (c) C6H14 and CCl4 (d) CCl4 and CH3OH 174a 6-29 The solubility of aspartic acid in water is 0.500 g in 100 mL at 25°C If we dissolve 0.251 g of aspartic acid in 50.0 mL of water at 50°C and let the solution cool to 25°C without stirring, shaking, or otherwise disturbing the solution, would the resulting solution be a saturated, unsaturated, or supersaturated solution? Explain 6-30 Near a power plant, warm water is discharged into a river Sometimes dead fish are observed in the area Why fish die in the warm water? 6-31 If a bottle of beer is allowed to stand for several hours after being opened, it becomes “flat” (it loses CO2) Explain 6-32 Would you expect the solubility of ammonia gas in water at atm pressure to be: (a) greater than, (b) the same as, or (c) smaller than at 0.5 atm pressure? section 6-5 What Are the Most Common Units for Concentration? 6-33 Verify the following statements (a) One part per million corresponds to one minute in two years, or a single penny in $10,000 (b) One part per billion corresponds to one minute in 2000 years, or a single penny in $10 million 6-34 Describe how we would make the following solutions: (a) 500.0 mL of a 5.32% w/w H2S solution in water (b) 342.0 mL of a 0.443% w/w benzene solution in toluene (c) 12.5 mL of a 34.2% w/w dimethyl sulfoxide solution in acetone 6-35 Describe how we would prepare the following solutions: (a) 280 mL of a 27% v/v solution of ethanol, C2H6O, in water (b) 435 mL of a 1.8% v/v solution of ethyl acetate, C4H8O2, in water (c) 1.65 L of an 8.00% v/v solution of benzene, C6H6, in chloroform, CHCl3 6-36 Describe how we would prepare the following solutions: (a) 250 mL of a 3.6% w/v solution of NaCl in water (b) 625 mL of a 4.9% w/v solution of glycine, C2H5NO2, in water (c) 43.5 mL of a 13.7% w/v solution of Na2SO4 in water (d) 518 mL of a 2.1% w/v solution of acetone, C3H6O, in water 6-37 Calculate the w/v percentage of each of these solutes: (a) 623 mg of casein in 15.0 mL of milk (b) 74 mg of vitamin C in 250 mL of orange juice (c) 3.25 g of sucrose in 186 mL of coffee 6-38 Describe how we would prepare 250 mL of 0.10 M NaOH from solid NaOH and water 6-39 Assuming that the appropriate volumetric flasks are available, describe how we would make these solutions: (a) 175 mL of a 1.14 M solution of NH4Br in water (b) 1.35 L of a 0.825 M solution of NaI in water Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it 174b 6-40 6-41 6-42 6-43 6-44 6-45 6-46 6-47 6-48 6-49 6-50 6-51 6-52 Chapter Solutions and Colloids (c) 330 mL of a 0.16 M solution of ethanol, C2H6O, in water What is the molarity of each solution? (a) 47 g of KCl dissolved in enough water to give 375 mL of solution (b) 82.6 g of sucrose, C12H22O11, dissolved in enough water to give 725 mL of solution (c) 9.3 g of ammonium sulfate, (NH4) 2SO4, dissolved in enough water to give 2.35 L of solution A teardrop with a volume of 0.5 mL contains 5.0 mg NaCl What is the molarity of the NaCl in the teardrop? The concentration of stomach acid, HCl, is approximately 0.10 M What volume of stomach acid contains 0.25 mg of HCl? The label on a sparkling cider says it contains 22.0 g glucose (C6H12O6), 190 mg K1, and 4.00 mg Na1 per serving of 240 mL of cider Calculate the molarities of these ingredients in the sparkling cider If 3.18 g BaCl2 is dissolved in enough solvent to make 500.0 mL of solution, what is the molarity of this solution? The label on a jar of jam says it contains 13 g of sucrose, C12H22O11 per tablespoon (15 mL) What is the molarity of sucrose in the jam? A particular toothpaste contains 0.17 g NaF in 75 mL toothpaste What are the percent w/v and the molarity of NaF in the toothpaste? A student has a bottle labeled 0.750% albumin solution The bottle contains exactly 5.00 mL How much water must the student add to make the concentration of albumin become 0.125%? How many grams of solute are present in each of the following aqueous solutions? (a) 575 mL of a 2.00 M solution of nitric acid, HNO3 (b) 1.65 L of a 0.286 M solution of alanine, C3H7NO2 (c) 320 mL of a 0.0081 M solution of calcium sulfate, CaSO4 A student has a stock solution of 30.0% w/v H2O2 (hydrogen peroxide) Describe how the student should prepare 250 mL of a 0.25% w/v H2O2 solution To make 5.0 L of a fruit punch that contains 10% v/v ethanol, how much 95% v/v ethanol must be mixed with how much fruit juice? A pill weighing 325 mg contains the following What is the concentration of each in ppm? (a) 12.5 mg Captopril, a medication for high blood pressure (b) 22 mg Mg21 (c) 0.27 mg Ca21 One slice of enriched bread weighing 80 g contains 70 mg of folic acid What is the concentration of folic acid in ppm and ppb? 6-53 Dioxin is considered to be poisonous in concentrations above ppb If a lake containing 107 L has been contaminated by 0.1 g of dioxin, did the concentration reach a dangerous level? 6-54 An industrial wastewater contains 3.60 ppb cadmium, Cd21 How many mg of Cd21 could be recovered from a ton (1016 kg) of this wastewater? 6-55 According to the label on a piece of cheese, one serving of 28 g provides the following daily values: 2% of Fe, 6% of Ca, and 6% of vitamin A The recommended daily allowance (RDA) of each of these nutrients are as follows: 15 mg Fe, 1200 mg Ca, and 0.800 mg vitamin A Calculate the concentrations of each of these nutrients in the cheese in ppm section 6-6 Why Is Water Such a Good Solvent? 6-56 Answer true or false (a) The properties that make water a good solvent are its polarity and its capacity for hydrogen bonding (b) When ionic compounds dissolve in water, their ions become solvated by water molecules (c) The term “water of hydration” refers to the number of water molecules that surround an ion in aqueous solution (d) The term “anhydrous” means “without water.” (e) An electrolyte is a substance that dissolves in water to give a solution that conducts electricity (f) In a solution that conducts electricity, cations migrate toward the cathode and anions migrate toward the anode (g) Ions must be present in a solution for the solution to conduct electricity (h) Distilled water is a nonelectrolyte (i) A strong electrolyte is a substance that dissociates completely into ions in aqueous solution ( j) All compounds that dissolve in water are electrolytes 6-57 Considering polarities, electronegativities, and similar concepts learned in Chapter 3, classify each of the following as a strong electrolyte, a weak electrolyte, or a nonelectrolyte (a) KCl (b) C2H6O (ethanol) (c) NaOH (d) HCl (e) C6H12O6 (glucose) 6-58 Which of the following would produce the brightest light in the conductance apparatus shown in Figure 6-11? (a) 0.1 M KCl (b) 0.1 M (NH4)3PO4 (c) 0.5 M sucrose 6-59 Ethanol is very soluble in water Describe how water dissolves ethanol 6-60 Predict which of these covalent compounds is soluble in water (a) C2H6 (b) CH3OH (c) HF (d) NH3 (e) CCl4 Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it Problems section 6-7 What Are Colloids? 6-61 Answer true or false (a) A colloid is a state of matter intermediate between a solution and a suspension, in which particles are large enough to scatter light but too small to settle out from solution (b) Colloidal solutions appear cloudy because the colloidal particles are large enough to scatter visible light 6-62 A type of car tire is made of synthetic rubber in which carbon black particles of the size of 200–500 nm are randomly dispersed Because carbon black absorbs light, we not see any turbidity (that is, a Tyndall effect) Do we consider a tire to be a colloidal system, and if so, what kind? Explain 6-63 On the basis of Tables 6-1 and 6-2, classify the following systems as homogeneous, heterogeneous, or colloidal mixtures (a) Physiological saline solution (b) Orange juice (c) A cloud (d) Wet sand (e) Soap suds (f) Milk 6-64 Table 6-2 shows no examples of a gas-in-gas colloidal system Considering the definition of a colloid, explain why 6-65 A solution of protein is transparent at room temperature When it is cooled to 10°C, it becomes turbid What causes this change in appearance? 6-66 What gives nanotubes their unique optical and electrical properties? 6-73 In each case, tell which side (if either) rises and why The solvent is water A osmosis 6-72 In an apparatus using a semipermeable membrane, a 0.005 M glucose (a small molecule) solution yielded an osmotic pressure of 10 mm Hg What kind of osmotic pressure change would you expect if instead of a semipermeable membrane you used a dialysis membrane? B Osmotic membrane A 6-74 6-75 section 6-8 What Is a Colligative Property? 6-67 Calculate the freezing points of solutions made by dissolving 1.00 mole of each of the following ionic solutes in 1000 g of H2O (a) NaCl (b) MgCl2 (c) (NH4) 2CO3 (d) Al(HCO3) 6-68 If we add 175 g of ethylene glycol, C2H6O2, per 1000. g of water to a car radiator, what will be the freezing point of the solution? 6-69 Methanol, CH3OH, is used as an antifreeze How many grams of methanol would you need per 1000 g of water for an aqueous solution to stay liquid at 220.°C? 6-70 In winter, after a snowstorm, salt (NaCl) is spread to melt the ice on roads How many grams of salt per 1000 g of ice is needed to make it liquid at 25°C? 6-71 A M acetic acid (CH3COOH) solution lowers the freezing point by 28°C; a M KF solution yields a 215°C freezing-point depression What can account for this difference? 174c 6-76 6-77 B (a) 1% glucose 5% glucose (b) 0.1 M glucose 0.5 M glucose (c) M NaCl M glucose (d) M NaCl M K2SO4 (e) 3% NaCl 3% KCl (f) M NaBr M KCl An osmotic semipermeable membrane that allows only water to pass separates two compartments, A and B Compartment A contains 0.9% NaCl, and compartment B contains 3% glycerol, C3H8O3 (a) In which compartment will the level of solution rise? (b) Which compartment (if either) has the higher osmotic pressure? Calculate the osmolarity of each of the following solutions (a) 0.39 M Na2CO3 (b) 0.62 M Al(NO3) (c) 4.2 M LiBr (d) 0.009 M K3PO4 Two compartments are separated by a semipermeable osmotic membrane through which only water molecules can pass Compartment A contains a 0.3 M KCl solution, and compartment B contains a 0.2 M Na3PO4 solution Predict from which compartment the water will flow to the other compartment A 0.9% NaCl solution is isotonic with blood plasma Which solution would crenate red blood cells? (a) 0.3% NaCl (b) 0.9 M glucose (MW 180) (c) 0.9% glucose Chemical Connections 6-78 (Chemical Connections 6A) Oxides of nitrogen (NO, NO2, N2O3) are also responsible for acid rain Which acids can be formed from these nitrogen oxides? 6-79 (Chemical Connections 6A) What makes normal rainwater slightly acidic? 6-80 (Chemical Connections 6B) Why deep-sea divers use a helium–oxygen mixture in their tanks instead of air? 6-81 (Chemical Connections 6B) What is nitrogen narcosis? 6-82 (Chemical Connections 6C) A solution contains 54 mEq/L of Cl2 and 12 mEq/L of HCO32 If Na1 is the only cation present in the solution, what is the Na1 concentration in milliequivalents per liter? Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it 174d Chapter Solutions and Colloids 6-83 (Chemical Connections 6C) The concentration of Ca21 ion present in a blood sample is found to be 4.6 mEq/L How many milligrams of Ca21 ion are present in 250.0 mL of the blood? 6-84 (Chemical Connections 6D) What is the chemical formula for the main component of limestone and marble? 6-85 (Chemical Connections 6D) Write balanced equations (two steps) for the conversion of marble to gypsum dihydrate 6-86 (Chemical Connections 6E) What is the protective colloid in milk? 6-87 (Chemical Connections 6F) What is the minimum pressure on seawater that will force water to flow from the concentrated solution into the dilute solution? 6-88 (Chemical Connections 6F) The osmotic pressure generated across a semipermeable membrane by a solution is directly proportional to its osmolarity Given the data in Chemical Connections 6F on the purification of seawater, estimate what pressure you would need to apply to purify brackish water containing 5000 ppm salt by reverse osmosis 6-89 (Chemical Connections 6G) A manufacturing error occurred in the isotonic solution used in hemodialysis Instead of 0.2% NaHCO3, 0.2% of KHCO3 was added Did this error change the labeled tonicity of the solution? If so, is the resulting solution hypotonic or hypertonic? Would such an error create an electrolyte imbalance in the patient’s blood? Explain 6-90 (Chemical Connections 6G) The artificial kidney machine uses a solution containing 0.6% w/v NaCl, 0.04% w/v KCl, 0.2% w/v NaHCO3, and 0.72% w/v glucose Show that this is an isotonic solution Additional Problems 6-91 When a cucumber is put into a saline solution to pickle it, the cucumber shrinks; when a prune is put into the same solution, the prune swells Explain what happens in each case 6-92 A solution of As2O3 has a molarity of 10 25 M What is this concentration in ppm? (Assume that the density of the solution is 1.00 g/mL.) 6-93 Two bottles of water are carbonated, with CO2 gas being added, under atm pressure and then capped One bottle is stored at room temperature; the other is stored in the refrigerator When the bottle stored at room temperature is opened, large bubbles escape, along with a third of the water The bottle stored in the refrigerator is opened without frothing or bubbles escaping Explain 6-94 How many grams of ethylene glycol must be added to 1000 g of water to create an automobile radiator coolant mixture that will not freeze at 215°C? 6-95 Both methanol, CH3OH, and ethylene glycol, C2H6O2, are used as antifreeze Which is more efficient—that is, which produces a lower freezing point if equal weights of each are added to the same weight of water? 6-96 We know that a 0.89% saline (NaCl) solution is isotonic with blood In a real-life emergency, you run out of physiological saline solution and have only 6-97 6-98 6-99 6-100 6-101 6-102 6-103 6-104 6-105 KCl as a salt and distilled water Would it be acceptable to make a 0.89% aqueous KCl solution and use it for intravenous infusion? Explain Carbon dioxide and sulfur dioxide are soluble in water because they react with water Write possible equations for these reactions A reagent label shows that the reagent contains 0.05 ppm lead as a contaminant How many grams of lead are present in 5.0 g of the reagent? A concentrated nitric acid solution contains 35% HNO3 How would we prepare 300 mL of 4.5% solution? Which will have greater osmotic pressure? (a) A 0.9% w/v NaCl solution (b) A 25% w/v solution of a nondissociating dextran with a molecular weight of 15,000 Government regulations permit a ppb concentration of a certain pollutant How many grams of pollutant are allowed in ton (1016 kg) of water? The average osmolarity of seawater is 1.18 osmol How much pure water would have to be added to 1.0 mL of seawater for it to achieve the osmolarity of blood (0.30 osmol)? A swimming pool containing 20,000 L of water is chlorinated to have a final Cl2 concentration of 0.00500 M What is the Cl2 concentration in ppm? How many kilograms of Cl2 were added to the swimming pool to reach this concentration? The density of a solution that is 20.0% HClO4 is 1.138 g/mL Calculate the molarity of the solution A 10.0% H2SO4 solution has a density of 1.07 g/mL How many milliliters of solution contain 8.37 g of H2SO4? looking Ahead 6-106 Synovial fluid that exists in joints is a colloidal solution of hyaluronic acid (Section 20-6A) in water To isolate hyaluronic acid from synovial fluid, a biochemist adds ethanol, C2H6O, to bring the solution to 65% ethanol The hyaluronic acid precipitates upon standing What makes the hyaluronic acid solution unstable and causes it to precipitate? Challenge Problems 6-107 A solution is made by dissolving 25.0 g of magnesium chloride crystals in 1000 g of water (a) What will be the freezing point of the new solution assuming complete dissociation of the MgCl2 salt? (b) Determine the boiling point of the new solution assuming complete dissociation of the MgCl2 salt 6-108 Explain why saltwater fish not survive when they are suddenly transferred to a freshwater aquarium 6-109 Consider the reaction of 1.46 g Ca(s) with 115 mL of 0.325 M HBr(aq) according to the following unbalanced chemical equation: Ca(s) HBr(aq) h CaBr2(aq) H2(g) Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it Problems The hydrogen produced was collected by displacement of water at 228C with a total pressure of 754 torr (a) Which reactant is the limiting reagent? (Chapter 4) (b) Determine the volume (in L) of hydrogen gas produced if the vapor pressure of water at 228C is 21 torr (Chapter 5) (c) How many grams of the other reactant are left over? (Chapter 4) 6-110 Vitamin B2, riboflavin, is a nondissociating molecular compound soluble in water If 370.3 g of riboflavin is dissolved in 1000.0 g of water, the resulting solution has a freezing point of 21.83°C (a) What is the molar mass of riboflavin? (Chapter 4) (b) Consider the skeletal structure of riboflavin, where all the bonded atoms are shown but double bonds, triple bonds, and/or lone pairs are missing Complete the structure as shown below (Chapter 3) O H H3C H3C C C C C H C C N N H2C H O C C C N CH CH O CH H2C NH C H O O H Riboflavin skeletal structure O H 174e 6-111 As noted in Section 6-8C, the amount of external pressure that must be applied to a more concentrated solution to stop the passage of solvent molecules across a semipermeable membrane is known as the osmotic pressure (π) The osmotic pressure obeys a law similar in form to the ideal gas law (discussed in Section 5-4), where PV = nRT Substituting π for pressure and solving for osmotic pressures gives the following equation: p a Vn b RT MRT, where M is the concentration or molarity of the solution (a) Determine the osmotic pressure at 25°C of a 0.0020 M sucrose (C12H22O11) solution (b) Seawater contains 3.4 g of salts for every liter of solution Assuming the solute consists entirely of NaCl (and complete dissociation of the NaCl salt), calculate the osmotic pressure of seawater at 25°C (c) The average osmotic pressure of blood is 7.7 atm at 25°C What concentration of glucose (C6H12O6) will be isotonic with blood? (d) Lysozyme is an enzyme that breaks bacterial cell walls A solution containing 0.150 g of this enzyme in 210 mL of solution has an osmotic pressure of 0.953 torr at 25°C What is the molar mass of lysozyme? (e) The osmotic pressure of an aqueous solution of a certain protein was measured in order to determine the protein’s molar mass The solution contained 3.50 mg of protein dissolved in sufficient water to form 5.00 mL of solution The osmotic pressure of the solution at 25°C was found to be 1.54 torr Calculate the molar mass of the protein 6-112 List the following aqueous solutions in order of increasing boiling point: 0.060 M glucose (C6H12O6), 0.025 M LiBr, and 0.025 M Zn(NO3)2 Assume complete dissociation of any salts 6-113 List the following aqueous solutions in order of decreasing freezing point: 0.040 M glycerin (C3H8O3), 0.025 M NaBr, and 0.015 M Al(NO3)3 Assume complete dissociation of any salts Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it Copyright 2016 Cengage Learning All Rights Reserved May not be copied, scanned, or duplicated, in whole or in part Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s) Editorial review has deemed that any suppressed content does not materially affect the overall learning experience Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it ... to remove additional content at any time if subsequent rights restrictions require it Introduction to General, Organic, and Biochemistry, Eleventh Edition Frederick A Bettelheim, William H Brown,. .. William H Brown, Mary K Campbell, Shawn O Farrell, Omar J Torres Product Director: Mary Finch Product Manager: Maureen Rosener Content Developer: Alyssa White Product Assistant: Christopher Robinson... right to remove additional content at any time if subsequent rights restrictions require it IntroductIon to General, organic, and Biochemistry ElEvEnth Edition Frederick A Bettelheim William