Question

${{N}_{2}}$ gas is absorbed by:
(a) calcium hydroxide
(b) ferrous sulphate
(c) calcium carbide
(d) aluminum carbide

Answer 1

Hint: Nitrogen is a colorless, odorless gas and is absorbed by the carbide of the alkali metal which occupies the 1st group of the periodic table and has the atomic number as 20 and mass number as 40. Now you can easily identify that carbide.

Complete Solution :
- Nitrogen is a metal which belongs to the p-block of the periodic table and occupies the 15th group and 2nd period in the periodic table.
- It has an atomic number as 7 and mass number as 14 .
- When two nitrogen atoms combine together, it results in the formation of nitrogen molecules i.e. nitrogen gas.
- Nitrogen gas is a colorless and odorless gas and is highly poisonous in nature and is used in the industries i.e. in the synthesis of ammonia.

Now considering the statement:
Nitrogen gas can be absorbed best by the calcium carbide. Calcium carbide is formed by the reaction between the calcium and carbon.
Calcium carbide absorbs this gas at very temperature and results in the formation of the compound known as the calcium cyanide. The reaction is supposed to take place as:
$Ca{{C}_{2}}+{{N}_{2}}\to Ca{{(CN)}_{2}}$
So, ${{N}_{2}}$ gas is absorbed by calcium carbide.
So, the correct answer is “Option B”.

Note: Calcium cyanide is an inorganic compound which has the chemical formula as $Ca{{(CN)}_{2}}$ and it is solid in nature and blackish- grey in colour. It is readily soluble in water and in soluble and is also soluble in weak acids like the acetic acid etc.