5 tablespoons of detergent
2 cups of warm water
4 tablespoons of salt
1 large, empty glass container
Dissolve the detergent in 1 cup of water by thoroughly stirring it.
Do the same with the salt in another cup and stir till it is completely dissolved
Pour the soap solution into the large glass container and then pour the salt solution on top of it. Mix the solutions well. You will notice that the soap will harden immediately. Leave the solution for a few more minutes and you will see that the soap will collect on the top, leaving a clear solution at the bottom.
How does this work?
This is how a bar of soap is actually made, and this process is called ‘salting out the soap’. This happens because, salt contains chemicals that react with soap molecules, causing them to harden and settle on top. Soap manufacturers use large kettles and remove the soap before it hardens, in order to add perfumes and colour to it. The soap can also be placed in moulds before hardening, to give the desired shapes.