Question
Explain the process of preparation of soap in laboratory.
✓
Answer
Soap can be prepared in the laboratory as follows:
- Take about 20ml of castor oil (cottonseed oil, linseed oil or soya bean oil) in a beaker.
- Add 30ml of 20% sodium hydroxide solution to it.
- Heat the mixture with constant stirring till a paste of soap is formed.
- Then add 5 to 10 grams of common salt (sodium chloride).
- Stir the mixture well and allow it to cool. On cooling the solution, solid soap separates out.
- When the soap sets, it can be cut into pieces called ‘soap bars’.
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