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प्रश्न
Give a scientific explanation.
Soap forms a precipitate in hard water.
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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.
Describe in brief the cleansing action of soap.
Explain the formation of scum when hard water is treated with soap.
While studying the saponification reaction, what do you observe when you mix an equal amount of colourless vegetable oil and 20% aqueous solution of NaOH in a beaker?
(A) The colour of the mixture has become dark brown
(B) A brisk effervescence is taking place in the beaker
(C) The outer surface of the beaker has become hot
(D) The outer surface of the beaker has become cold
Why is soap not suitable for washing clothes when the water is hard?
Why have detergents replaced soap as a washing agent?
What is the advantage of detergents over soaps for washing clothes? Also state one disadvantage.
Explain the cleansing action of soap. Draw diagrams to illustrate your answer.
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
What are detergents chemically? List two merits and two demerits of using detergents for cleansing. State the reason for the suitability of detergents for washing, event in the case of water having calcium and magnesium ions.
Distinguish between esterification and saponification reactions of organic compounds.
How will you check with the help of soap powder whether water is hard?
What is meant by ‘surface activity’?
Name three chemicals responsible for the surface activity of various detergents.
What are the differences between Soap and synthetic detergent?
Water, coconut oil, and _______ are necessary for soap preparation.
What are the two different types of molecules found in the soap?
______ are substances which can undergo chemical changes to produce certain materials.
______ molecules go and join with dirt and oil in the cloth.
What are the similarities between Soap and synthetic detergent.
