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Carbon and its Compounds — Science STD 10 — Question

CBSE BoardEnglish MediumSTD 10ScienceCarbon and its Compounds3 Marks
Question
Explain the process of preparation of soap in laboratory.
✓

Answer

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

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