National Chemistry Week - Experiments - An Absorbency Experiment

Try this experiment see how a small amount of absorbent material can take up many times its own mass in water.

You will need:

• 4 thin-style diapers
• scissors
• piece of paper
• 1 drinking glass
• water
• salt
• spoon for stirring

What to do:

1. Cut open each diaper on the inside using a pair of scissors.

2. Remove the cottony stuffing and pull it apart over a piece of paper to collect the powder from inside the diaper. Pour this powder into a glass.

3. There should be about 5 ml (1 teaspoon) of material at the bottom of the glass.

4. Place 45 ml (3 tablespoons) of water in the glass over the material.

5. Swirl the water around slightly.

6. Make observations.

You will notice that the water soon turns to a gel. You can turn the glass upside-down and no water will spill out of the glass. It only takes a small amount of powder to turn the water to a gel.

To make the experiment ever more amazing add about 5 ml (1 teaspoon) of salt to the gel and stir. The gel turns back into a liquid! The salt actually breaks the bonds that were formed during the gelatinizing process.