Advertisements
Advertisements
प्रश्न
What is a soap? Name one soap.
उत्तर
Soap is a mixture of sodium or potassium salts of various natural fatty acids and oils, which when used with water show cleansing properties. A soap contains a large, non-ionic hydrocarbon group and an ionic group COO-Na+.
An example for a soap is sodium stearate (C17H35COO-Na+). It is a salt of sodium of fatty acid called stearic acid with a non-ionic hydrocarbon group C17H35, and an ionic carboxylate group COO- Na+.
APPEARS IN
संबंधित प्रश्न
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
Which of the following sets of materials can be used for conducting a saponification reaction for the preparation of soap?
(a) Ca(OH)2 and neem oil
(b) NaOH and neem oil
(c) NaOH and mineral oil
(d) Ca(OH)2 and mineral oil
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 advantage of detergents over soaps for washing clothes? Also state one disadvantage.
Answer the following question.
In three test tubes A, B, and C, three different liquids namely, distilled water, underground water and distilled water in which a pinch of calcium sulphate is dissolved, respectively are taken. Equal amount of soap Answer is added to each test tube and the contents are shaken. In which test tube will the length of the foam (lather) be longest? Justify your answer.
What are the differences between Bath soap and soap for washing clothes?
Explain why often coloured spots are formed on clothes during washing.
Match the following
| 1. | Soap | C6H5 OH |
| 2. | Cement | CaSO4.2H2O |
| 3. | Fertilizers | NaOH |
| 4. | Gypsum | RCC |
| 5. | Phenol | NPK |
In the soap micelles
