Create colorful, bubbling ice cubes that react when they touch water! Learn about chemical reactions between acids and bases in a fun, frozen experiment.

Tools

• ice cube tray
• small mixing bowls (4)
• spoons (4)
• dropper or small spoon

Materials

• baking soda (1 cup)
• water (1 cup)
• white vinegar (1/2 cup)
• food coloring (4 different colors, 2 drops each)
• dish soap (1 tbsp)

Safety

• Adult supervision required when handling vinegar.
• Avoid contact with eyes; if vinegar gets in eyes, rinse immediately with water.
• Ensure children do not eat the fizzy ice cubes.
• Do not eat or drink any materials used in this project.
• Protect work surface. Materials may stain clothing.
• Adult supervision required for children under 8.

Steps

1. In four separate mixing bowls, add 1/4 cup of baking soda to each.
2. Add 1/4 cup of water to each bowl and stir until the baking soda is mostly dissolved.
3. Add 1 tablespoon of dish soap to the mixture (divided among the bowls) to make the bubbles last longer.
4. Add 2 drops of a different food coloring to each bowl and stir until the color is vibrant.
5. Carefully pour the colorful baking soda mixtures into the compartments of the ice cube tray.
6. Place the tray in the freezer and let the cubes freeze completely (usually 4-6 hours or overnight).
7. Once frozen, pour a small amount of white vinegar into a shallow tray or plate.
8. Using a spoon or dropper, place a fizzy ice cube into the vinegar and watch it bubble and fizz!
9. Experiment by adding more vinegar to the cube to see how the reaction changes.