A CAI Preparation-for-Chemistry Course
The second program, CH40.BAS, has the three simple types of densitv findine" mass. volume. or densitv. Three -oroblems: . levels of help are provided. The third program, CH251.BAS, asks three types of ideal pas law problems. The first type has four subtypes, which are l o ~olve-forvolume. nressure. temoerature. or amount of eas.
James W. Beatty and Earle S. Scott Ripon College Ripon. Wisconsin 54971
Five years ago we decided we needed a course to prepare about 30% of our students for our general chemistry course. " ". These students have inadequate backgrounds in chemistry, quantity of gas may be given in moles or grams. In the latter hut most~ of all thev have~lost confidence in their ~ahilitv to~ ~ ~ ~ case. the name of the eas is eiven and the user must find and solve mathematical problems. The purposes of the course are use the molecular weight. he temperature may he in degrees to restore their confidence, to teach them how to use electronic Celsius or kelvins. The volume may be liters, milliliters, or m3. calculators, to make correct calculations with ease, and to The pressure may be in atm, mm-Hg, torr, or pascals. Each learn the fundamentals of uroblem solvina in chemistry. Onlv of the above is chosen randomly with agreater orohability of basic ideas and calculations are stressedbecause we want to choosing the more common units in each case. A difficulty prepare them for a general chemistry course and not to teach parameter may be set to any of four levels. them general chemistry. The fourth program, ATSTR.BAS, asks the following eight A text of about 100 pages and nine computer assisted intypes of problems: struction (CAI) programs were written. The book consists of ten chapters. There is a program for all hut the first chapter, which is on the technique of problem solving. The complementary CAI programs for chapters two through ten are: (1) 3) Names or notation for the four quantum numbers. Mathematical Review, (2) Dimensional Analysis and 4) Meaning of each of the four quantum numbers. Graphing, (3) Chemical Formulas, Molecular Mass, and the 5 ) Permitted values of the four quantum numbers or number of electrons in a shell, subshell, or an orbital. Mole Concent., (4) . . Densitv Calculations.. (5) . . Ideal Gases. (6) 6) Bohr theory, its qualitative assumptions and E, = hu. Empirical Formula and Percent Composition, (7) ~ o l & 7 ) Bright line spectra, c = Xu, or AE = hv with numbers. and the Preparation of Solutions, (8) Nomenclature, Including 8) Bohr theory of hydrogen spectra using Rydberg's constant or Common Ions, and (9) Balancing Chemical Equations. The the ionization potential. programs parallel chapters in the text and have similar names. The programs are independent of the text in the sense that The first four types are not suited for any help levels. Most of anv eood chemistrv. . oroblem book could be used. Our text is the rest are suited to no more than one level of heln. limited by design. In all of these CAI programs the student's grade is given to Versions of the moerams are available that will run on all him at the end of the run, and it is also written in a disk file for . . ('ornm~Iuretnivrt~~.otiipl~ters having ah "I' Ithhl. Irom the the instructor. Certainly the first three programs are suitable small-ke\.btmrtl IJfZl' Wrll to thr i'HV lo'cs.32. Tht ~ ~ r t r < r ; i t ~ ~ > for use hy high school students, and all are suitahle for firstare straightforward drill programs, which a student can go year college science students. The average college student throuah in about 15 minutes. Surorisingly, students take notes could benefit bv usine them for review even after the first vear. Actually, thesebave ieen added to a collection of 20 o t h e ; ~ ~ ~ without encouragement. At the;equ&t of the students, the programs give a score at the end. Students routinely repeat (4). oroerams . . a program until they achieve a satisfactory level of perfor111('Hioaild partiallnrlv i n ('H251, asnvll 111:111y(dthe mance. Numbers and chemical formulas in problems are se~ numt m , r i d rdculati~m u t h u ('.A1 1mgrams in cur c o l k c ~ ~ 4 lected randomly by the program. is rcquind to uhtain the anaver. \\'it11thr prwalci~ce01 pr~ckrr The P E T was selected because it is self-contained and . ~ ,a hlA'I'tl aubcalculators, this vr,,vidcs lirtlr I I ~ o I I I Ihut makes it easy to present chemical formulas in their desired routine ha; beenwritten in BASIC thatpermits input of an form, such as F e ( N 0 3 ) ~and Mg2+ using superscripts and entire arithmetical expression, called S$, in place of a single subscrint,s.,and uooercase and lowercase letters. Some of the number requested for the answer. The MATH suhroutine .. programs give background information. If an incorrect answer then analyzes S$ and converts it by the specified calculations is entered, the correct answer is given with details on how to to a single number that is returned to the main program as the calculate it. The programs do not offer assistance in the sense value of the variable S . This is then checked for correctness. that manv believe a comouter should. Memorv limitations. 'l'hia ,ul~r
