iW -ttj h, f* tatl til a If :iJ i i 1 If «g( e ! ^i-x.1 a • Jj- i \ j * j 7 ] 1 Acids and Bases _ I f-* -—"T Before you order chemicals again, stop and think. If you've been ordering from the same chemical We carry over 25,000 catalog items in addition to suppliers for years, stop and think about it. You could chemicals, so we're also your best "one-stop" source be getting better quality and much more reliable for other science teaching products as well. So when service at a better price. you put together your next chemical order, start a new Carolina has been supplying chemicals to the habit—the Carolina habit. scientific community for over 30 years. We keep thousands of chemical products in stock year-round, Want more information? Write us or call our Customer so you're assured of getting what you need, and at Service Department at 919 584-0381. competitive prices. And our professional staff has the experience and dedication to make sure you get what you need when you need it—our service is unsurpassed. Get the Carolina habit. Carolina Biological Supply company 2700 York Road Box 187 Burlington, North Carolina 27215 Gladstone, Oregon 97027 CkOe No. * on Header*" inquiry Card Today's academic laboratory is a modern Who flowmeters, and other equipment facility that trains students to control them properly. for careers in the high tech- Safety in the laboratory is Says It's an nology job market. Such a important. To aid you in the laboratory needs equipment safe handling and storage and supplies that are as Ivor u Tower? of gases, we have flash sophisticated as the laboratories that arresters, toxic gas detector systems, hand will one day employ these students. Matheson trucks and cylinder stands. We also have a has a complete selection of gases and equipment system for buying back empty lecture bottles for the modern laboratory. We have more than so that you won't be stuck with a disposal 80 different gases and prepare gas mixtures to problem. Keep your students in the forefront your specifications. No matter which gas or of technology. Send for a catalog describing mixture you use, Matheson has regulators, our products, prices and specifications. Matheson belongs in the modem laboratory. BSgatheson ••Gas Products World Leatie30 Seavief *wn SpecialtDrive, Secaucuay Gase, sN J& 07094 Circle No, 15 on Readers' Inquiry Card Volume 61 Number 2 February 1984 A33 idea A way to bore a smooth, uniform, straight, properly sized hole in a rubber stopper —quickly, easily, safely and with any desired orientation. Required are{1)a Anyone who has bored effortlessly—and even novel cutter grooved to a rubber stopper by hand off-center or at an angle, bring fresh lubricant to knows that it is a case of as desired. the cutting edge and trading hard work for A large selection of other areas of the cutter: poor results. At best, the interchangeable cutters stopper interface con- hole is ragged, non- provides the exact bore tinuously during the uniform and frequently size for every application boring operation and (2) crooked. and corks and rubber a modified drill press Custom boring need stoppers of any size can which drives the cutter not be so frustrating an be accommodated. Hole and sets its orientation to experience. With our sizes start at 3 mm and the stopper. Power Boring Machine range to 22 and 32 mm stoppers (and corks) are for stoppers and corks, bored perfectly-with a Clean power Cut bore respectively. straight, smooth, uniform contrasts with one bored bore-quickly, safely and manually Put these two together The Power Boring and you have our Power Machine includes six Boring Machine— a real commonly used cutters, skin and temper saver three holders for small which belongs in any stoppers, a bottle of laboratory doing even a lubricant, an ejecting rod, moderate volume of cus- a cutter sharpener and a tom boring of stoppers. 3-wire cord and plug. We have lileraiure on the S-23207 POWER BORING Sargent-Welch Power Borer. For MACHINE—Portable, Electric, your copy, phone, write or circie Sargent-Welch. For 115 volt, the reader service number. 60 Hz A.C 675.00 ISH& SARGENT-WELCH SCIENTIFIC COMPANY 7300 NORTH UNDER AVENUE • SKOKIE, ILLINOIS 60077 • (312) 677-0600 Anahelm/Blrmlngham/Chicago/ClevelaiMJ/Dallas/Donver/DetroH/Springliek), N.j./Toronto/Monlreal Circle No. 23 on Readers' Inquiry Card A34 Journal of Chemical Education J. J. LAGOWSKI, Editor University ol Texas at Austin FEBRUARY 1984 Volume 61, Number 2 Austin, Texas 7S712 Assistant Editor: JOURflflL Of Debora Ann Bittaker Editorial Assistants Linda Davis Kyle George V. Oliver Chemical Education Rebecca Chambers Marie S. Stephens Owned anfl Published by the DIVISION OF CHEMCAL EDUCATION OF THE AMERICAN CHEMICAL SOCIETY JAMES V. DEROSE Publications Coordinator ADVERTISING MANAGEMENT CENTCOM, LTD. P.O. Box 231 25 Sylvan Road South Articles in this Issue Westport, Connecticut 06881 (2031226-7131 (For Hsf ot offices, see pags A40) The G. N. Lewis Symposium NEW PRODUCTS Shirley Sieratzki 93 The Research Style of Gilbert N. Lewis: Acids and Bases Journal of Chemicai Education Centcom, t-td. Glenn T. Seaborg 60 East 42nd St. New York, N.Y. 10165 101 The Generalized Lewis Acid-Base Theory: Surprising Recent (212)972-9660 Developments Leo Brewer 104 G. N. Lewis and the Thermodynamics ol Strong Electrolytes Subscription Fulfillment Department 201h S Northampton Sts. Kenneth S. Pitzer Easton, Pa. 18042 108 Gilbert N. Lewis and the Beginnings of Isotope Chemistry Jacob Bigeleisen SECONDARY SCHOOL EDITOR Mickey Sarquis Miami University-Middletown Middletown, OH 45042 ASSOCIATIONS EDITORS Articles of General Interest VaSuDev California Association of Chemistry Teachers 100 Another Procedure for Writing Lewis Structures Thomas J. Clark Percy Ehrlich 117 The Effect of Neutral Ions on Acid-Base Balance Loyd E. Poplin New England Association of Chemistry Teachers 119 The Bonds of Conformity: W. A. Noyes and the Initial Failure of the Lewis Theory in America Martin D. Saitzman BOARD OF PUBLICATION 129 Equilibrium Binding and Steady-State Enzyme Kinetics: An Approach Division of Chemical Education j. A. Sell Emphasizing Their Commonality H. Brian Dunford D. W. Brooks W. B. Cook 133 The Evaluation of Strain and Stabilization In Molecules using G. A. Crosby tsodesmic Reactions Richard Fuchs D. A. Davenport M. H. Gardner 136 Recommended Format for the Periodic Table of the Elements D. Kofb American Chemical Society Committee on Nomenclature W. J. Stratton 137 Atomic Volume and Allot ropy of the Elements Charles N. Slngman 143 Some Opportunities for Reinforcement of Learning among the Subdfsciplines of Chemistry A. L. Underwood 1S8 Models to Depict Hybridization of Atomic Orbitals C. T. Stubbiefield 173 Error in the Minimum Free Energy Curve Grover Willis and David Ball The Cover Each of the photographs shows six test tubes arranged in the f of Jo wing se- Features quence 31 Editorially Speaking Aqueous Non-AqiiBous 146 Provocative Opinion: Trends and Issues in international Chemical acid neutral base acid neutral Base + Education Marjorie Gardner H water OH" solvent Et3N 155 Cooperative Education: Development of a Cooperative Education To the test tubes in tie lop set the indicator Program at the University of Victoria Alexander McAuley bromthymol blue has been added, to those in the bottom set brorncresol purple. The 159 Real World of Industrial Chemistry: A Private Corporation as Part ol general slmiiarity, though not identity, of the a Chemistry Department: An Eleven-Year Synergism indicator colors produced by the addition Richard E. Bayer of acids and bases in the aqueous and 161 Report ol the Polymer Core Course Committee: Polymer Samples for non-aqueous systems is apparent. (Photo- College Classrooms graphs by George M. Bodner and Derek A. Raymond B. Seymour and Gerald S. Kirshenbaum Davenport) 164 Computer Series, 49: Bits and Pieces, 19 edited by John W. Moore 172 Tested Demonstrations edited by George L. Gilbert 181 Division of Chemical Education: Report of the ACS Examinations Committee (Continued on pane A36) Volume 61 Number 2 February 1984 A35 A45 Safety In the Chemical Laboratory edited by Malcolm M. Renfrew The Chemical Management: A Method tor Waste Reduction Stanley H. Pine Parr 1451 A53 Chemical Instrumentation In the Laboratory edited by Frank A. Settle, Jr. Solution Choosing the Right Instrument: The Modular Approach, Part I Calorimeter Howard A. Strobe! A convenient bench-top instru- A58 Out of the Editor's Basket edited by James A. Goldman ment for measuring enthalpy A67 Book Reviews changes produced by chemical reactions in solution, with provision for conversion to a semimicro bomb calorimeter. Secondary School Chemistry A Multi-Purpose Calorimeter Utilizing a unique rotating 124 Chemical Principles Revisited: Tfce "6N+2 Rule" lor Writing Lewis Octet sample cell and a sensitive Structures Mehrin E. Zandier and Erach R. Talaty electronic thermometer, the 128 Applications end Analogies edited by Ron DeLorenzo 1451 Solution Calorimeter pro- 145 A New Approach to Overhead Projection Timothy L. Schaap vides a moderately priced and 148 Chemical Bonds: The Role of the Humanities in the Teaching ot Chemistry easily operated instrument for Dominick A. Labianca measuring: 151 View from the Classroom: "The Fundamental Things Apply As Time Goes By" • Heats of Reaction Frank Cardulta • Heats of Solution 156 Delaware Science Olympiad John C. Cairns • Heats of Mixing • Heats of Dilution 174 Chemical of the Month: NHric Add Sardul S. Pannu • Heats of Wetting 180 What's Happening in Your Part of the Country? with a precision adequate for most analytical and exploratory research applications. Energy changes ranging from 2 to 1000 Laboratory Experiments calories in either liquid-liquid or Squid-solid systems can be 177 Modification of a Microwave Oven for Laboratory Use measured in a straightforward Judith Andrews and George F.