Write the time the bubbling ends in each cup in the chart. Alka-Seltzer reacts with an acid to make carbon dioxide gas. When you added the tablet to the vinegar or water, you heard fizzing and saw ...

This is very similar to the way vinegar (a solution of acetic acid) reacts with baking soda to produce a gas. Show students an effervescent tablet, like Alka-Seltzer. Explain that the tablet is ...