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प्रश्न
Why is common salt (sodium chloride) added during the preparation of soap?
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उत्तर
Common salt (sodium hydroxide) is added during the preparation of soap to separate the soap from the aqueous solution. On adding common salt, the solubility of the soap present in the solution decreases. This allows the soap to be taken out of the solution in its solid form.
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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?
A student takes four test tubes marked P, Q, R and S of 25 mL capacity and fills 10 mL of distilled water in each. He dissolves one spoon full of four different salts in each as − KCl in P, NaCl in Q, CaCl2 in R and MgCl2 in S. He then adds about 2 mL of a sample of soap solution to each of the above test tubes. On shaking the contents of each of the test tubes, he is likely to observe a good amount of lather (foam) in the test tubes marked
(a) P and Q
(b) R and S
(c) P, Q and R
(d) P, Q and S
Would you be able to check if water is hard by using a detergent?
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
Mention the essential material (chemicals) to prepare soap in the laboratory. Describe in brief the test of determining the nature (acidic/alkaline) of the reaction mixture of saponification reaction.
What is saponification? Write the chemical equation of the reaction involved in this process. Name all the substances which take part in this process and also those which are formed.
The soap molecule has a ______.
The chemical which is not required for the preparation of soap in the laboratory is:
(a) vegetable oil
(b) baking soda
(c) caustic soda
(d) common salt
Why are soaps not suitable for washing clothes when the water is hard?
Give a scientific explanation.
Soap forms a precipitate in hard water.
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?
Name three chemicals responsible for the surface activity of various detergents.
What are the two different types of molecules found in the soap?
Analogy:
Used to join components: Adhesives:: Clean the body ______.
How does soap clean clothes?
- Write the formula and draw electron dot structure of carbon tetrachloride.
- What is saponification? Write the reaction involved in this process.
