Question

 Nitrolim is a mixture of:
A. $Ca{{C}_{2}}+{{N}_{2}}$
B. $CaC{{N}_{2}}+graphite$
C. $CaNCN+diamond$
D. $Ca{{(CN)}_{2}}+C$

Answer 1

Hint:The compound given in the question is used as an inorganic nitrogenous fertilizer and has a very important agricultural use. It serves as a source of nitrogen for the soil. In common terms, it is also known as “lime nitrogen”.

Complete step by step answer:  
Nitrolim is a chemical compound which is also known as calcium cyanide. But commercially, it is known by the name “lime nitrogen”. Here, the word nitrolim is an alteration used for nitro-lime. We know calcium cyanide has the chemical formula $CaC{{N}_{2}}$. So, nitrolim has the same chemical formula as of calcium cyanide.
Let’s see how calcium cyanide is produced:
Calcium cyanide was first synthesized by Adolph Frank and Nikodem Caro (the reaction is known as Frank-Caro process) in $1898$.
So, as per the reaction when nitrogen is passed over calcium carbide at a suitable temperature (i.e. around ${{1000}^{o}}-{{1100}^{o}}C$), we get a mixture of nitrolim which is a mixture of calcium cyanide and carbon. The balanced chemical reaction is shown below:
$Ca{{C}_{2}}+{{N}_{2}}\to CaC{{N}_{2}}+C$
Nitrolim is also used to produce sodium cyanide by fusing with sodium carbonate. The reaction can be shown as:
$CaC{{N}_{2}}+N{{a}_{2}}C{{O}_{3}}+2C\to 2NaCN+CaO+2CO$
So, we can see that the products formed are calcium cyanide i.e. $CaC{{N}_{2}}$ and carbon, which we can say as graphite (crystalline form of carbon).
Hence, the correct option is B.

Additional Information:
Uses of nitrolim:
- The main use of nitrolim is as a fertilizer in agriculture. When nitrolim reacts with water, it decomposes and liberates ammonia. The reaction is shown below:
$CaC{{N}_{2}}+3{{H}_{2}}O\to 2N{{H}_{3}}+CaC{{O}_{3}}$
- Nitrolim is also used as a wire-fed alloy in steel making for the purpose of introducing nitrogen into the stell.

Note: Graphite is a crystalline form of carbon with its atoms arranged in a hexagonal structure. It occurs in this form and is regarded as the most stable form of carbon under standard conditions. Under high pressures and temperatures, it converts to diamond.