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प्रश्न
Describe the structure of a soap molecule with the help of a diagram.
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उत्तर
A molecule of soap has a tadpole like structure and is made up of two parts, a long hydrocarbon part and a short ionic part. The hydrocarbon part of the soap molecule is soluble in grease and oil but remains insoluble in water (hydrophobic), whereas the short ionic group is soluble in water (hydrophilic) because of the polar nature of the water molecules.
The structure of a soap molecule is as follows:
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संबंधित प्रश्न
While preparing soap a small quantity of common salt is generally added to the reaction mixture of vegetable oil and sodium hydroxide. Which one of the following may be the purpose of adding common salt?
(A) To reduce the basic nature of the soap
(B) To make the soap neutral
(C) To enhance the cleansing power of the soap
(D) To favour the precipitation of the soap
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
Explain the formation of scum when hard water is treated with soap.
What change will you observe if you test soap with litmus paper (red and blue)?
State one use of esterfication process.
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
Explain esterification reaction with the help of a chemical equation. Describe an activity to show esterification.
What change will you observe if you test soap solution with a litmus paper (red and blue)? Give reason for your observation.
Give reasons for the following observation:
Use of synthetic detergents causes pollution of water.
What is a detergent?
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 takes 4 mL of distilled water in each of four test tubes I, II, III and IV, and then dissolves an equal amount of four different salts namely NaCl in I, CaCl2 in II, MgCl2 in III and KCl in IV. He then adds 8 drops of the given soap solution to each test tube and shakes the contents of the test tube 10 times. In which test tubes will enough lather (foam) be formed ?
(A) I and II
(B) II and III
(C) I and IV
(D) III and IV
What is a soap?
Explain why soap cannot be used in hard water.
What are the two different types of molecules found in the soap?
______ to remove strong strains on the clothes.
______ are substances which can undergo chemical changes to produce certain materials.
- Write the formula and draw electron dot structure of carbon tetrachloride.
- What is saponification? Write the reaction involved in this process.
What are soaps?
