What you need:

• icing sugar
• sodium bicarbonate (baking soda)
• citric acid powder (in the supermarket baking section)
• lollipops
• plastic cups

What to do:

1. Mix together:
   – 1 tablespoon icing sugar
   – 1 teaspoon baking soda
   – 1 teaspoon citric acid
2. Lick your lollipop.
3. Dip your wet lollipop into the mixture and lick the lollipop again.
4. Feel what’s happening on your tongue.
5. Dip again (or eat the sherbet with a spoon)!
6. Experiment with different amounts of the ingredients,but be careful of having too much citric acid or it will taste very sour.

What’s happening?

The dry ingredients are dissolving in the saliva in your mouth and then reacting with one another. You might remember from high school chemistry that:

acid + carbonate –> carbon dioxide + salt + water

C₆H₈O₇ + 3NaHCO₃ –> 3CO₂ + Na₃C₆H₅O₇ + 3H₂O

And that’s the reaction happening here.

The fizzing you can feel is tiny bubbles of CO₂ being produced and popping on your wet tongue.