Advertisements
Advertisements
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
Advertisements
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
APPEARS IN
संबंधित प्रश्न
Consider the following comments about saponification reactions:
I. Heat is evolved in these reactions.
II. For quick precipitation of soap, sodium chloride is added to the reaction mixtures.
III. Saponification reactions are a special kind of neutralisation reactions.
IV. Soaps are basic salts of long-chain fatty acids.
The correct comments are
(a) I, II and III
(b) II, III and IV
(c) I, II and IV
(d) Only I and IV
In order to study saponification reaction, we first prepare 20% solution of sodium hydroxide. If we record the temperature of this solution just after adding sodium hydroxide flakes to water and also test its nature using litmus, it may be concluded that the process of making this solution is
(A) exothermic and the solution is alkaline
(B) endothermic and the solution is alkaline
(C) endothermic and the solution is acidic
(D) exothermic and the solution is acidic
Complete the following chemical equations: CH3COOH+NaHCO3→
Write the formulae of methanoic acid.
How is ethanoic acid obtained from ethanol? Write down the chemical equation of the reaction involved.
What do you observe when acetic acid is added to ethyl alcohol in the presence of sulphuric acid?
On adding NaHCO3 to acetic acid, a gas is evolved which turns lime water milky due to the formation of:
(1) Calcium bicarbonate
(2) Calcium hydroxide
(3) Calcium carbonate
(4) Calcium acetate
Why is Soda lime used not only NaOH?
Write the chemical equation for the following:
Combustion of methane
When acetaldehyde is oxidized with acidified potassium dichromate, it forms ______.
