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प्रश्न
Give a scientific explanation.
Soap forms a precipitate in hard water.
उत्तर
When soap is mixed with hard water calcium and magnesium salts of fatty acids are formed. These being water insoluble they form a precipitate and that is why lather is not formed.
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संबंधित प्रश्न
Differentiate between Toilet soap and Laundry soap.
Both soap and detergent are some type of salts. What is the difference between them?
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
Would you be able to check if water is hard by using a detergent?
Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also?
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
(C) Sodium sulphate, Calcium sulphate
(D) Calcium sulphate, Calcium chloride
How is soap made? Write a word equation involved in soap making.
What is a soap? Name one soap.
The chemical mostly used in the preparation of most of the soaps we use is
(a) Sodium chloride
(b) Potassium hydroxide
(c) Sodium hydroxide
(a) Potassium chloride
A student is testing water to know which is best for cleansing purposes with soaps. He would find that the cleansing action of soaps is best when he uses water obtained from
(a) rain
(b) tap
(c) hand pump
(d) pond
Why are soaps not suitable for washing clothes when the water is hard?
Soap is a salt of ______ and sodium hydroxide.
How will you check with the help of soap powder whether water is hard?
What are the differences between Bath soap and soap for washing clothes?
Explain why synthetic detergents are superior to soap.
Match the following
| 1. | Soap | C6H5 OH |
| 2. | Cement | CaSO4.2H2O |
| 3. | Fertilizers | NaOH |
| 4. | Gypsum | RCC |
| 5. | Phenol | NPK |
What are the three main constituents of soap?
Soaps are ester of which type of acids?
In the soap micelles
What are soaps?
