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Question
How will you check with the help of soap powder whether water is hard?
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Solution
- In hard water (from a well or a tube well), soap does not foam but instead creates scum.
- As a result, soap loses its cleaning ability. So, using soap, we can determine that the water is hard.
RELATED QUESTIONS
List two problems that arise due to the use of detergents instead of soaps.
What change will you observe if you test soap with litmus paper (red and blue)?
A student requires hard water for an experiment in his laboratory which is not available in the neighbouring area. In the laboratory there are some salts, which when dissolved in distilled water can convert it into hard water. Select from the following groups of salts, a group, each salt of which when dissolved in distilled water will make it hard.
(A) Sodium chloride, Potassium chloride
(B) Sodium sulphate, Potassium sulphate
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Analogy:
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