Alka-seltzer Lab Pointers

Alka-seltzer labs are great. Let's look at ways to tweak these labs.  First, what in an Alka-seltzer tablet?  The two key ingredients are citric acid and sodium hydrogen carbonate, otherwise known as baking soda.  What are the proportions?  We can use a balanced chemical equation for the reaction between baking soda and citric acid. (Scroll down the pages of this link for the balance chemical reaction.  BTW, this link has ideas for experiments!). The ratio between baking soda to citric acid is 3 moles to 1 mole.  Each tablet has 1 gram of citric acid and 1.9 grams of baking soda.  You can let kids  adjust the ratios of citric acid and baking soda to determine the ratio to produce the best results.  Compare these ratios to a tablet of Alka-seltzer or generic tablets.  Kids can do a lot of experimentation.  Want a fun way to end the lab?  Make bath bombs!  Do this with your Co-op class and provide small bags.  The kids can get a leg up making Christmas presents.