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प्रश्न
Why do soaps not form lather in hard water?
उत्तर
Soaps do not form lather in hard water because
Hard water contains calcium and magnesium salts. Soap molecules react with calcium and magnesium salts to form an insoluble precipitate called scum.
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संबंधित प्रश्न
Hard water is not available for an experiment. Some salts are given below :
(I) Sodium chloride
(II) Sodium sulphate
(III) Calcium chloride
(IV) Calcium sulphate
(V) Potassium chloride
(VI) Magnesium sulphate
Select from the following group of these salts, each member of which may be dissolved in water to make it hard.
(A) I, II, V
(B) I, III, V
(C) III, IV, VI
(D) II, IV, VI
What change will you observe if you test soap with litmus paper (red and blue)?
State one use of saponification process.
What change will you observe if you test soap solution with a litmus paper (red and blue)? Give reason for your observation.
Why is soap not suitable for washing clothes when the water is hard?
What is the difference between the chemical composition of soaps and detergents? State in brief the action of soaps in removing an oily spot from a shirt. Why are sops not considered suitable for washing where water is hard?
What is the difference between soaps and detergents? State, in brief, the cleansing action of soaps in removing an oily spot from a fabric. Why are soaps not very effective when a fabric is washed in hard water? How is this problem resolved?
What is meant by 'surface activity'?
Arrange the following statements in correct sequence
- Pour that solution into an empty matchbox, soap can be obtained after drying.
- Take the necessary quantity of water in a jar.
- Then add coconut oil drop by drop and stir it well.
- Add concentrated sodium hydroxide in the jar and allow it to cool.
- Try this soap to wash your hand kerchief.
- Cover your work area with old newspaper.
______ to remove strong strains on the clothes.
