Experiments in Physical Chemistry - Daily Dialectic

1 Is comprehensive laboratory text includes 48 Experiments with background theoretical information, complete experimental descriptions, safety recommendations, and computer applications. Updated chapters are provided regarding the collection and analysis of data and the use of spreadsheets and other scientifi c software. Supplementary instructor information regarding necessary supplies, equipment, and procedures is provided in an integrated manner in the text. ree of the Experiments are completely new, and all make use of optical measure- ments. One involves a temperature study of the birefringence in a liquid crystal to determine the evolution of nematic order as one approaches the transition to an isotropic phase.

2 E second uses dynamic laser light scattering from an aqueous dispersion of polystyrene spheres to determine the autocorrelation function that characterizes the size of these particles . e third is a study of the absorption and fl uorescence spectra of CdSe nanocrystals (quantum dots) and involves modeling of these in terms of simple quantum mechanical concepts. Experiments in Physical ChemistryEighth EditionEighthEditionGarlandNiblerShoemak erExperiments in Physical ChemistryExperiments inPhysical ChemistryCarl W. GarlandJoseph W. NiblerDavid P. ShoemakerEighth EditionMD DALIM 943693 1/15/08 CYAN MAG YELO BLACKRev. Confirming Pages CARL W. GARLAND Massachusetts Institute of Technology JOSEPH W.

3 NIBLER Oregon State University DAVID P. SHOEMAKER (deceased ) Oregon State University Experiments IN Physical Chemistry EIGHTH EDITION gar28420_fm_i-x igar28420_fm_i-x i1/25/08 9:41:39 PM1/25/08 9:41:39 PMRev. Confirming PagesEXPERIMENTS IN Physical Chemistry , EIGHTH EDITIONP ublished by McGraw-Hill, a business unit of The McGraw-Hill Companies, Inc., 1221 Avenue of the Americas, New York, NY 10020. Copyright 2009 by The McGraw-Hill Companies, Inc. All rights reserved. Previous editions 2003, 1996, 1989, 1981, 1974, 1967, 1962. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of The McGraw-Hill Companies, Inc.

4 , including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance ancillaries, including electronic and print components, may not be available to customers outside the United States. This book is printed on recycled, acid-free paper containing 10% postconsumer 2 3 4 5 6 7 8 9 0 QPD/QPD 0 9 8 ISBN 978 0 07 282842 9 MHID 0 07 282842 0 Publisher: Thomas TimpSenior Sponsoring Editor: Tamara L. HodgeDirector of Development: Kristine TibbettsSenior Developmental Editor: Shirley R. OberbroecklingMarketing Manager: Todd L. TurnerSenior Project Manager: Kay J. BrimeyerSenior Production Supervisor: Kara KudronowiczAssociate Design Coordinator: Brenda A. RolwesCover Designer: Studio Montage, St. Louis, MissouriCompositor: Laserwords Private LimitedTypeface: 10/12 Times RomanPrinter: Quebecor World Dubuque, IACover description: The figure depicts the absorption and emission spectra of CdSe nanocrystals, whose color is a sensitive function of size .

5 The figure is based on spectral data provided by NN-Labs. The authors thank both NN-Labs and Evident Technologies for CdSe samples used in the development of the quantum dot of Congress Cataloging-in-Publication DataGarland, Carl W. Experiments in Physical Chemistry . 8th ed. / Carl W. Garland, Joseph W. Nibler, David P. Shoemaker. p. cm. Includes index. ISBN 978 0 07 282842 9 ISBN 0 07 282842 0 (hard copy : acid-free paper)1. Chemistry , Physical and theoretical Laboratory manuals. I. Nibler, Joseph W. II. Shoemaker, David P. III. Title. QD457 .S56 2009 dc22 iigar28420_fm_i-x ii1/25/08 10:53:13 PM1/25/08 10:53:13 PMConfirming Pagesiii Contents Preface ix I. INTRODUCTION 1 Organization of the Book 2 Preparation for an Experiment 4 Execution of an Experiment 4 Safety 6 Recording of Experimental Data 7 Literature Work 9 Reports 10 Sample Report 13 Special Projects 26 Ethics 27 II.

6 TREATMENT OF EXPERIMENTAL DATA 29 A. Calculations and Presentation of Data 29 Significant Figures 30 Precision of Calculations 31 Analytical Methods 32 Numerical Methods 33 Graphs and Graphical Methods 34 Exercises 37 B. Uncertainties in Data and Results 38 Errors 38 Rejection of Discordant Data 42 Statistical Treatment of Random Errors 43 Propagation of Errors 52 Case History of an Error Evaluation 59 Fundamental Limitations on Instrumental Precision 61 Summary 64 Exercises 65 iii gar28420_fm_i-x iiigar28420_fm_i-x iii1/17/08 5:13:34 PM1/17/08 5:13:34 PMConfirming Pagesiv Contents III. USE OF COMPUTERS 68 Word Processors 68 Spreadsheets 69 Symbolic Mathematics Programs 79 Quantum Mechanical Programs 82 Interfacing with Experiments 85 Exercises 88 IV.

7 GASES 91 1. Gas Thermometry 91 2. Joule Thomson Effect 98 3. Heat-Capacity Ratios for Gases 106 V. TRANSPORT PROPERTIES OF GASES 119 Kinetic Theory of Transport Phenomena 119 4. Viscosity of Gases 128 5. Diffusion of Gases 136 VI. THERMOCHEMISTRY 145 Principles of Calorimetry 145 6. Heats of Combustion 152 7. Strain Energy of the Cyclopropane Ring 158 8. Heats of Ionic Reaction 167 VII. SOLUTIONS 172 9. Partial Molar Volume 172 10. Cryoscopic Determination of Molar Mass 179 11. Freezing-Point Depression of Strong and Weak Electrolytes 188 12. Chemical Equilibrium in Solution 193 VIII. PHASE BEHAVIOR 199 13. Vapor Pressure of a Pure Liquid 199 14.

8 Binary Liquid Vapor Phase Diagram 207 15. Ordering in Nematic Liquid Crystals 215 16. Liquid Vapor Coexistence Curve and the Critical Point 229 IX. ELECTROCHEMISTRY 235 17. Conductance of Solutions 235 18. Temperature Dependence of emf 245 19. Activity Coefficients from Cell Measurements 248 X. CHEMICAL KINETICS 254 20. Method of Initial Rates: Iodine Clock 254 21. NMR Study of a Reversible Hydrolysis Reaction 263 22. Enzyme Kinetics: Inversion of Sucrose 271 23. Kinetics of the Decomposition of Benzenediazonium Ion 283 24. Gas-Phase Kinetics 287 gar28420_fm_i-x ivgar28420_fm_i-x iv1/17/08 5:13:34 PM1/17/08 5:13:34 PMConfirming PagesContents v XI. SURFACE PHENOMENA 299 25.

9 Surface Tension of Solutions 299 26. Physical Adsorption of Gases 308 XII. MACROMOLECULES 318 27. Intrinsic Viscosity: Chain Linkage in Polyvinyl Alcohol 318 28. Helix Coil Transition in Polypeptides 327 XIII. ELECTRIC, MAGNETIC, AND OPTICAL PROPERTIES 336 29. Dipole Moment of Polar Molecules in Solution 336 30. Dipole Moment of HCl Molecules in the Gas Phase 347 31. Magnetic Susceptibility 361 32. NMR Determination of Paramagnetic Susceptibility 371 33. Dynamic Light Scattering 379 XIV. SPECTROSCOPY 393 34. Absorption Spectrum of a Conjugated Dye 393 35. Raman Spectroscopy: Vibrational Spectrum of CCl 4 398 36. Stimulated Raman Spectra of Benzene 407 37.

10 Vibrational Rotational Spectra of HCl and DCl 416 38. Vibrational Rotational Spectra of Acetylenes 424 39. Absorption and Emission Spectra of I 2 436 40. Fluorescence Lifetime and Quenching in I 2 Vapor 446 41. Electron Spin Resonance Spectroscopy 454 42. NMR Determination of Keto Enol Equilibrium Constants 466 43. NMR Study of Gas-Phase DCl HBr Isotopic Exchange Reaction 475 44. Solid-State Lasers: Radiative Properties of Ruby Crystals 484 45. Spectroscopic Properties of CdSe Nanocrystals 492 XV. SOLIDS 500 46. Determination of Crystal Structure by X-Ray diffraction 500 47. Lattice Energy of Solid Argon 515 48. Statistical Thermodynamics of Iodine Sublimation 523 XVI.