RESEARCH PROJECT FOR GENERAL CHEMISTRY LABORATORY' JEAN SCHWOLOW Carleton College, Northfield, Minnesota
J o m HILDEBRANDhas said, 'Chemistry is what chemists do and how they do it."2 By this definition, many standard experiments in general chemistry often fail to teach realistic chemistry. I n order to modify the routine experiment in which students know the answers before ever entering the laboratory, Carleton freshmen were presented with the following simulated research project connected with acids, bases, and p H measurements. Do ,you have a sour stomach from eating too much dorm food? Is the fun you would normally have in your afternoon labs ruined by acid indigestion? There are many products on the market today which claim t o be able to relieve such stomaoh distress: "Tums for the tummy," "Alka-Seltzer for that feel better feeling," etc. The makers of Tums claim their product "neutralizes only excess stomach acids." I'hilli~s Milk of Magnesia tablets are-claimed to "have a neutralizing power three likes that of a saturated solution of bicarbonate of aoda." Alks-Seltzer say8 that its "effervescent buffers ease stomach distress." noth Bayer Aspirin and Bufferin claim that they "will not upset the stomach," and, in addition, the makers of Bufferin say that it contains two antacid ingredientn. Using the standard pH aeries which you will prepare, it is possible t o investigate t h e ~ eclaims. y range from 2.9 The pH of the normal stomach content m to 4.5.' When the pH is much less than this, acid indigestion O~PUI.S.
Directions for setting up the standard p H series4 using a universal indicators were given. Then, since a typical stomach usually contains approximately 50 ml. gastric juices,%the manufacturers' maximum recommended dosages of each hyperacidity remedy were dissolved in separate 50-ml. aliquots of 0.1 M hydrochloric acid (pH = I), assuming here a "good case of acid indigestion." Two pain relieving remedies which claim not to upset the stomach were dissolved in 50-ml. aliquots of 0.001 M HCI in order to simulate the conditions in the normal stomach. The solutions were filtered to remove any undissolved material. The in-
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From s paper presented before 8th Annual Undergraduate Chemistry Symposium, sponsored by the Chicago Sertion, A.C.S., UePaul University, May 18, 1957. HILDEBRAND, JOEL H., "Science in the Making," Colombia University Press, New York, 1957, p. 7. BURGER,ALFRED,"Medicinal Chemistry," Interscience Publishers Inc., New York, 1951, Vol. I, p. 268. MALM,L. E., A N D H. W. FRANTZ, "College Chemistry in the Laboratory," No. 2, W. H. Freeman and Co., Siln Francisco, 1954, p. 190. RICHARDSON, F. R., J. CHEM. EDUC., 33, 517 (1956). 6 HOWELL, W. H., "Howell's Textbook of Physiology," J. F. Fulton, Editor, 15th ed., W. B. Saunders Company, Philadelphia, 1916, p. 1050.
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dicator was added and the p H determined by color comparison. The buffering capacity of Alka-Seltzer and Bufferin was also tested. The table shows the results obtained, the width on the pH scale revresenting the of results, At the conclusion of the experiment the students were asked to compare these data with each manufacturer's claims for his nroduct. Thev were also asked to discuss the factors limiting the validity of the conclusions based on these experimental results. Finally they were asked which remedy they would prescribe for their roommates' arid indigestion, and why they prescribed that remedy. Many students drew on their knowledge of biology in discussing the limitations of in aitro experiments, suggestions for refinement of technique were given, and most of the answers were well thought out and logically constructed. The response to this experiment, which mas quite different from the apathy often prevalent in the freshman laboratory, showed clearly that students are interested in doing something different. They were curious and interested in applying their knowledge of chemistry to a small research problem. A number of projects of this simulated research type have been conducted in general chemistry and evaluated by the students. Their evaluations show clearly that their interest in such projects is high and they feel they are learning chemistry by doing work which is to them challenging and "practical." ACKNOWLEDGMENT
The author would like to thank Dr. Frances Greef for encouragement and advice on this project.
JOURNAL OF CHEMICAL EDUCATION
