stoichiometry

As many chemistry teachers know, grading lab reports can be a very time-consuming task. For me, the lab report that has required the most time to grade is a stoichiometry lab that I have been doing the past couple years. Though we do at least four “formal” lab reports each year, what makes this one different is that it involves a lot more calculations and subsequent results than any of our other labs. Regardless of how well they organized their report or wrote their conclusions, their results need to be checked for accuracy. This takes time. Even after eventually being able to generally eyeball their work, it still takes more time than I would like. So, this year I finally decided to sit down and generate a tool for me to expedite this process—the stoichiometry calculator.

Students are told that they have to determine the amount of active ingredient in an antacid tablet. Then I ask them if they have any questions. First it starts with blank stares...then slowly the questions start coming. What exactly is the active ingredient? What does it react with? They are provided information that the active ingredient is baking soda.