Elephant's toothpaste

This Friday in science we learnt how make Elephant toothpaste. I was in a new group with Axle and Jeff. Basically, it is a mixture of Hydrogen peroxide, Dish washer liquid, food coloring and dry yeast. The reaction was caused  by rapid decomposition of hydrogen peroxide making use of yeast as the catalyst. The interesting part of the experiment was when the yeast mixing together with the hydrogen peroxide and dish washing liquid. 

Here are some photos that we took:

Elephant’s Toothpaste          7.9.2018

Resources:

• Safety glasses
• A cylinder
• Rubber gloves
• A tote tray to protect the bench from damage
• 120ml Hydrogen Peroxide 6%  
• Dishwash liquid
• Dry yeast
• Food colouring
• Funnel
• Tablespoon
• Beaker

Procedure:

1. Put on your gloves and goggles.
2. Put a tote tray on the bench and put your cylinder in the tote tray, with the funnel in the top.
3. Ask the teacher to pour the hydrogen peroxide into your cylinder (via the funnel).
4. Add 10 drops of food colouring to the cylinder (via the funnel).
5. Add a tablespoon of dishwash liquid to the bottle (via the funnel).
6. Swirl your cylinder around to mix everything together.
7. In a beaker, mix a tablespoon of dry yeast with 3 tablespoons of warm water and stir for 30 seconds.
8. Pour the yeast mixture into the cylinder (via the funnel).
9. Stand back and watch the chemical reaction!
10. Pour the mixture down the drain afterwards and wash out the cylinder.

Scientific Explanation (How it works):

The yeast and water mixture acts as a catalyst - something that speeds up a chemical reaction in another substance, while remaining unchanged itself. When you add this to the cylinder it makes the hydrogen peroxide break down into oxygen and water. The dishwashing liquid traps the oxygen in bubbles to create the foam. Just a small amount of hydrogen peroxide will create a lot of oxygen, so you get loads of bubbles - making your ‘toothpaste’ almost explode out of the cylinder.

Extra for experts:

1. Is your cylinder warm after the experiment? Why? The cylinder was warm because of the chemical reaction which produced energy in the form of heat.