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प्रश्न
For preparing soap in the laboratory we require an oil and a base. Which of the following combinations of an oil and a base would be best suited for the preparation of soap?
(a) Castor oil and calcium hydroxide
(b) Turpentine oil and sodium hydroxide
(c) Castor oil and sodium hydroxide
(d) Mustard oil and calcium hydroxide
For demonstrating the preparation of soap in the laboratory which of the following combinations of an oil and a base would be most suitable?
(a) Mustard oil and calcium hydroxide
(b) Castor oil and calcium hydroxide
(c) Turpentine oil and sodium hydroxide
(d) Mustard oil and sodium hydroxide
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उत्तर
Soaps are sodium or potassium salt of long-chain fatty acids. They are prepared by the reaction of a long-chain fatty acid with either NaOH or KOH. This reaction is known as the saponification reaction. Among the given sets of materials, as soap can be prepared by the reaction between sodium hydroxide (NaOH) and turpentine oil (long-chain fatty acid).
Hence, the correct answer is Turpentine oil and sodium hydroxide
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संबंधित प्रश्न
Ethanoic acid has a .................... odour.
(a) Rotten eggs
(b) Pungent
(c) Vinegar-like
(d) Mild
What do you observe when you drop a few drops of acetic acid to test tubes containing
(a) phenolphthalein
(b) distilled water
(c) universal indicator
(d) sodium hydrogen carbonate powder
What type to compound is CH3COOH?
What do you observe when acetic acid is added to ethyl alcohol in the presence of sulphuric acid?
A student puts a drop of acetic acid first on a blue litmus paper and then on a red litmus paper. He would observe that
(A) the red litmus paper turns colourless and there is no change in the blue litmus paper.
(B) the red litmus paper turns blue and the blue litmus paper turns red.
(C) there is no change in the red litmus paper and the blue litmus paper turns red.
(D) there is no change in the blue litmus paper and the red litmus paper turns blue.
In an experiment to study the properties of acetic acid a student takes about 2 mL of acetic acid in a dry test tube. He adds about 2 mL of water to it and shakes the test tube well. He is likely to observe that:
(A) the acetic acid dissolves readily in water
(B) the solution becomes light orange
(C) water floats over the surface of acetic acid
(D) acetic acid floats over the surface of water
Which of the following observations is true about dilute solution of acetic acid?
(A) It smells like vinegar and turns red litmus blue
(B) It smells like onion and turns blue litmus red
(C) It smells like orange and turns red litmus blue
(D) It smells like vinegar and turns blue litmus red
Give a balanced chemical equation for the following conversion:
Calcium carbide to ethyne.
Write the answers to the questions by observing the following figure.
- Write the chemical reaction shown in the figure above in the form of a balanced equation.
- Write the name of the gas coming out of the large test tube in the above chemical reaction.
- Why do small bubbles appear in the small test tube?
- What is the change in colour of lime water?
Observe the diagram given below and answer the questions:
- Name the reactants in this reaction.
- Which gas comes out as effervescence in the bigger test tube?
- What is the colour change in the lime water?
- In the above experiment instead of sodium carbonate which chemical can be used to get same products?
- Write the use of acetic acid.
