Lesson plan

Gases and foams

Summary
Produce gas and foams with different chemical reactions.
Science content
Chemistry: States of Matter, Properties of Materials (K-7)
Chemistry: Physical Changes, Solutions, Mixtures and Separating (2, 4, 5, 6)
Chemistry: Chemical Changes (2, 7)
Procedure

Explore some chemistry of making foams (and small explosions).

First try acid-base reactions that make gases:
1. Mix vinegar and baking soda to make carbon dioxide gas
2. Add Alka seltza tablets to water
Chemical reaction: HCO3 + H -> CO2 + H2O
The Alka seltza reaction can be sealed in a film canister, to make the lid blow off as the gas pressure rises.

Then break down hydrogen peroxide to make gas:
3. Elephant's toothpaste
2H2O2 -> O2 + 2H2O

Then make a foam fountain as gas rapidly comes out of solution.
4. Coke and mentos activity

Grades taught
Gr K
Gr 1
Gr 3
Gr 4
Gr 5
Teaching Site
Gordon Elementary Science Club