Molecular orbitals on a spreadsheet

Gambler, OH 43022. Chemistry on a Spreadsheet. J. Van Houten. St. Michael's College. Wlnooski. VT 05404. The advent of spreadsheet software for person...
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Chemistry on a Spreadsheet J. Van Houten St. Michael's College Wlnooski. VT 05404 The advent of spreadsheet software for personal computers has provided science educators a t all levels-grade school through grad school-with a new teaching tool. This article describes a number of approaches utilizing spreadsheets in chemical education. The applications described are aimed primarily a t high school and undergraduate-level teaching, although the aporaach is valid a t all levels. A variety 13f rhemirsl prohlerns involve repetitive ur iterative calculations in order to arr:ve at a graphical presentation o i the solution. Some familiar examples include kinetics, titration curves, gas law isotherms for ideal and nonideal gasses, reactions involving multiple equilibria, curve-fitting experimental data, and atomic and molecular orbital calculations. The cornouter is an ohvious option for solving such prohlema, hut the computer presents a prohlem of its own-it must be programmed. While many educators are proficient programmers, many more are not. Even some who have mastered the art of programming may prefer to spend their time on other pursuits. Spreadsheets have ameliorated the programming dilemma considerably. Spreadsheet programs can he used t o design routines for displaying the results of a wide variety of chemical calculations. Using a spreadsheet requires virtually no programming experience, and, once a user has become familiar with the mechanics of a particular spreadsheet package, the variety of potential applications is virtually limitless. For readers not familiar with soreadsherts.8 hriefdescription is provided. Pmhably the mmt popular rpreadshett package is LOTUS 1-2-3 from Lotus Develupmenl Corporation. A spreadsheet can be envisioned as a blank tablet ruled off into rows and columns of cells. The value of any cell can be expressed as a mathematical or logical function of the value(s) of any other cell(sl. . . The functions are written in the form of algebraic erpresaions with the cell ad. drerses as varialrlci; and the enpre~sionscan be quite rumplicated, involving trigonometric functions, logarithms, exponentiation, etc. Once an expression has been incorporated into a cell, that expression can be copied or "replicated" into additional cells where similar expressions are required, thus avoidine the neeessitv to rewrite eamolicated enpreasrons. Therein lies the p