National Chemistry Week - Experiments - Amazing Ice

THE AIM:

To examine what happens to the floating and sinking properties of water as it changes from a solid to a liquid in oil.

WHAT YOU WILL NEED:

• 1 tall drinking glass
• water
• cooking oil
• freezer
• ice cube tray
• food colouring

WHAT TO DO:

1. Add food colouring to the water in the ice cube tray. One ice cube per glass is all that is needed.
2. After the ice cubes are frozen fill the glass 3/4 full with cooking oil.
3. Gently place the ice cube in the oil.
4. Watch what happens as the ice starts to melt.
5. Encourage observations

We saw in the experiment Expansion on Freezing that ice takes up more space than water. This is why ice floats in a glass of water. Here the ice floats on the oil and the denser liquid water drops sink to the bottom.

Notice that water and oil do not mix together.

The ice cube will appear larger in the oil because the oil in the curved glass acts as a magnifier.