I think many of you guessed correctly (but were reluctant to have a Hermione Granger moment and actually say what your answer was…), the What Am I yesterday was in fact Alka-Selzer. *other varieties of soluble aspirin are available*
When I was looking up the ingredients on the internet because I’ve misplaced the box in my office (for research purposes only I might add, aspirin would not be my drug of choice), I noticed that Bayer Healthcare had some very nice experiments for students including alka-selzer rockets. How cool is that?
I’ve used Alka-Selzer and related products in a couple of labs that weren’t listed. Alka-Selzer generates CO2, that’s why its fizzy so I’ve used it as a CO2 source in an experiment to measure the RMM of CO2. The students measured CO2 generated from the sublimation of dry ice, reaction of calcium carbonate and acid, and the dissolution of Alka-Selzer and came up with various answers of varying degrees of accuracy. It worked quite well and we collected the gases in a variety of ways from zip-loc bags to gas syringes and measuring cylinders. I’m always a fan of laying out a variety of equipment and letting the students figure out what’s required. The other experiment made use of the aspirin content in an experiment to measure, by titration, the aspirin content of the tablets. In this case the students compared a variety of soluble and tablet forms of aspirin and used the ingredient lists to work out what was interfering with their results. Its a nice experiment given that the ‘answer’ (mass of aspirin) is printed on the box! Our results varied between products and between groups studying the same product, but that always leads to a good discussion of accuracy and admissions of experimental error.
I’ll do another What Am I next week, need to think a few up!