Carolina Chemonstrations®: Balloon Stoichiometry Kit
Bring some clarity to the topic of limiting and excess reagents with this demonstration that's both quick and memorable. Students watch balloons fill with carbon dioxide gas from the reaction of sodium bicarbonate and hydrochloric acid. The acid and base will vary between limiting and excess in 3 flasks, resulting in differently sized balloons and a pH indicator color change in the solution. Kit materials are sufficient for the demo to be performed 4 times.