Question

The by-products of solvay process is
(a)- $CaO$
(b)- $CaC{{l}_{2}}$
(c)- $C{{O}_{2}}$
(d)- $NaHC{{O}_{3}}$

Answer 1

Hint: Solvay process is a method in which soda ash is formed in which the main constituent is sodium carbonate. The reaction of the Solvay process is the formation of sodium carbonate and calcium chloride from sodium chloride and calcium carbonate.

Complete answer:
The Solvay process is also known as the ammonia-soda process which is the major industrial process that is used for the production of sodium carbonate also known as soda ash having formula $N{{a}_{2}}C{{O}_{3}}$. This process was developed in the 1860s by a Belgian chemist Ernest Solvay.
The reactants used in this reaction are easily available and are not expensive so, the reactants in this process are salt brine which can be obtained from sea having formula $NaCl$ and limestone which is obtained from quarries whose formula is $CaC{{O}_{3}}$. The reaction of the Solvay process is the formation of sodium carbonate and calcium chloride from sodium chloride and calcium carbonate. The reaction is given below:
$2NaCl+CaC{{O}_{3}}\to N{{a}_{2}}C{{O}_{3}}+CaC{{l}_{2}}$
So, in this process sodium carbonate is the main product and calcium chloride is the by-product.
This process takes place in four steps. In the first step, sodium chloride, carbon dioxide, ammonia, and water react together to form sodium bicarbonate and ammonium chloride. The reaction is given below:
$NaCl+C{{O}_{2}}+N{{H}_{3}}+{{H}_{2}}O\to NaHC{{O}_{3}}+N{{H}_{4}}Cl$
In the second step, the calcium carbonate is decomposed into carbon dioxide and calcium oxide. The reaction is given below:
$CaC{{O}_{3}}\to C{{O}_{2}}+CaO$
In the third step, the ammonium chloride and calcium oxide combine to form ammonia, calcium chloride, and water. The reaction is given below:
$2N{{H}_{4}}Cl+CaO\to 2N{{H}_{3}}+CaC{{l}_{2}}+{{H}_{2}}O$
In the last step, the sodium bicarbonate converts into sodium carbonate, water, and carbon dioxide. The reaction is given below:
$2NaHC{{O}_{3}}\to N{{a}_{2}}C{{O}_{3}}+{{H}_{2}}O+C{{O}_{2}}$

So, the correct answer is option (b)- $CaC{{l}_{2}}$

Note:
The carbon dioxide released in the fourth step is not the by-product it is used in the first step again. Only calcium chloride is the by-product which is not further used for any other process.