# Experiments: Soaps and Detergents

## Super Soap Bubbles

Safety Rules:
Parent supervision
Take care with glycerine (It is poisonous)
Do it outdoors

Materials you need are:
a large wire or plastic loop
a container
some glycerine (from the pharmacy)
some detergent
some water

Make a mixture of 5% detergent, nearly 50% glycerine and nearly 50% water. Dip your loop in and blow big bubbles.

## Compare Soaps, Detergents and Shampoos

Test different cleaning agents to compare their cleaning ability and their lather (amount of bubbles). Pour the same amount of soap, detergents and shampoo in same amount of water in different containers. Put equally dirty cloths into the containers and leave them overnight. Rinse each with the same amount of tap water and check which one cleans the best.

Again put equal amounts of the soaps, detergents and shampoos into containers with same amount of water. Stir them all equally. Measure the height of the lather.

You will probably find that detergents and shampoos have a lot of lathering chemicals to make you feel as though they are doing a great cleaning job but in fact the amount of lather is not always a good indication of the cleaning ability.

## How Much Water is in Liquid Detergent

Safety rules:
Parent supervision
Take care with fire or heat

Materials you need are:
liquid detergent
measuring scales
saucepan
stove

Measure 100 grams of liquid detergent into a saucepan. Heat it on a stove until it becomes almost dry. Do not overheat. When it is cool, weigh the 'dry' amount. Now subtract this weight from 11 grams and that gives the water amount in the liquid detergent.

This amount of water is a percentage.

## Make Hard Water

Safety rules:
Parent supervision
Take care with epsom salts (It is poisonous)

Materials you need are:
epsom salts (also called magnesium sulphate)
3 teaspoons
a container with a lid
water
detergent
butter or margarine

Half-fill the container with water. Smear some butter onto one teaspoon. Add 10 drops of detergent to the container and wash the greasy teaspoon. Observe the cleanliness of the spoon and the amount of lather produced. Empty the container.

Again half-fill the container with water but this time, use a clean teaspoon to add several teaspoons of epsom salts and stir thoroughly to dissolve as much as possible. You have made 'hard' water. Take another clean teaspoon and smear the same amount of butter onto it. Add 10 drops of detergent and try to wash it in the water with epsom salts. Again observe the cleanliness of the spoon and the amount of lather.

'Hard' water is water containing a lot of magnesium or calcium salts. It produces very little lather, and does not clean well.