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प्रश्न
What change will you observe if you test soap solution with a litmus paper (red and blue)? Give reason for your observation.
उत्तर
Soap is the salt of a strong base (sodium hydroxide) and a weak acid (carboxylic acid); therefore, it's solution with water will be also basic in nature. Hence, it will turn a red litmus paper blue.
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संबंधित प्रश्न
A student takes about 4 ml of distilled water in four test tubes marked P, Q, R and S. He then dissolves in each test tube an equal amount of one salt in one test tube, namely sodium sulphate in P, potassium sulphate in Q, calcium sulphate in R and magnesium sulphate in S. After that he adds an equal amount of soap solution in each test tube. On shaking each of these test tubes well, he observes a good amount of lather (foam) in the test tube marked
(A) P and Q
(B) Q and R
(C) P, Q and S
(D) P, R and S
In a locality, hard water, required for an experiment, is not available. However, the following salts are available in the school laboratory:
1. Sodium sulphate
2. Calcium sulphate
3. Magnesium chloride
4. Sodium chloride
5. Calcium chloride
6. Potassium sulphate
Which of the above salts may be dissolved in water to obtain hard water for the experiment?
(A) 2, 3 and 5
(B) 1, 2 and 5
(C) 1, 2, 4 and 6
(D) 3 and 5 only
Fill in the following blank with suitable word:
............. is better than soap for washing clothes when the water is hard.
Explain the process of preparation of soap in laboratory.
Why is common salt (sodium chloride) added during the preparation of soap?
What is the advantage of detergents over soaps for washing clothes? Also state one disadvantage.
The soap molecule has a ______.
What is meant by 'surface activity'?
Explain why often coloured spots are formed on clothes during washing.
TFM in soaps represents ______ content in soap.
