PolyToday: Reaction in a Bag

Seventh graders recently conducted a hands-on chemistry lab that reveals how chemical reactions unfold in real time.

Working with three substances—sodium bicarbonate, calcium chlorate, and phenol red—students carefully placed the materials inside a sealed plastic bag and gently mixed the contents. Within moments, the bag began to inflate, and the mixture grew warm in their hands, clear signs that a chemical reaction was underway.

The Class of 2031 then repeated the experiment using different combinations of the substances to determine which ingredients produced the reaction. By comparing the results across trials, students could see how specific chemical pairings led to observable changes.