Goal:
- Observe what happens when baking soda is mixed with vinegar.
- Notice the chemical reaction that creates bubbles and foam (lava effect).
- Connect a science experiment with an autumn theme (pumpkin).
Materials:
- Small hollowed-out pumpkin
- Baking soda
- Vinegar (preferably clear, white vinegar)
- Food coloring (optional – orange, red, or yellow)
- Small cup or container
- Spoon
Procedure:
Hollow out the inside of the pumpkin and place it on a tray.
Put a small cup or container inside the pumpkin.
Add 2–3 tablespoons of baking soda to the cup.
Add a few drops of food coloring.
Slowly pour vinegar into the cup.
Observe what happens when the vinegar and baking soda mix.
Observations:
When the two substances combine, foam and bubbles begin to form.
The foam flows out of the pumpkin, looking like lava flowing from a volcano.
Children can observe, describe, and comment on the changes.
Children can observe, describe, and comment on the changes.
Explanation:
- Baking soda (a base) and vinegar (an acid) react to create carbon dioxide (CO₂).
- The gas forms bubbles and causes the foam to overflow — just like a lava eruption.
Expected Learning Outcomes:
- Children observe and recognize changes in matter (formation of bubbles and foam).
- Children develop curiosity and interest in science experiments.
- Children can describe what they saw in simple sentences.
- Children connect the experiment with natural phenomena (e.g., volcanic eruption).



