Students in middle school and high school learn that the rate of a chemical reaction can be affected by concentration, surface area, temperature, and catalysts.
This simple experiment compares the rate of reaction using ground chalk (greater surface area) and whole pieces of chalk (less surface area) when chalk reacts with vinegar. The expected result is an increased rate of reaction when greater surface area of the chalk is exposed.
This lab also allows students to learn how to use a mortar and pestle to make ground chalk for the experiment.
My students had a blast doing this!