Question

Explain the process of preparation of soap in laboratory.

Answer 1

(a) Following is the process of preparing soap in the laboratory:
Raw materials required are:

(i) Vegetable oil like castor oil
(ii) Sodium hydroxide (caustic soda), and
(iii) Sodium chloride (common salt)

Steps involved in the preparation of soap are:

1. Take a beaker with about 20 ml of castor oil in it.
2. Also, add 30 ml of 20% sodium hydroxide to the beaker.
3. Heat the mixture and stir it constantly until a soap is formed.
4. Add 5-10 grams of common salt to it and stir the mixture. On cooling the solution, we will see the solid soap getting separated.
5. The solid soap, once separated, is made to set, and then it is cut into pieces called soap bars.