Question

The by-product of Solvay-ammonia process is:
A.$\text{C}{{\text{O}}_{\text{2}}}$
B.$\text{N}{{\text{H}}_{3}}$
C.$\text{CaC}{{\text{l}}_{\text{2}}}$
D.$\text{CaC}{{\text{O}}_{3}}$

Answer 1

Hint:The Solvay-ammonia process is also known as the ammonia-soda process. It is the major industrial process for the preparation of Soda Ash and was developed by Belgian Chemist Ernest Solvay during the 1860s.

Complete answer:
The Solvay-ammonia process was developed for the production of sodium carbonate which is also called “soda-ash”. The ingredients required are really inexpensive and are readily available: salt brine and limestone. The worldwide production of soda ash in 2005 was about 42 million metric tonnes which is more than six times per year for each person on Earth. Solvay based chemical plants now produce roughly three-quarters of this supply, with the remaining being mined from natural deposits. This method even superseded the Leblanc process.
In this process, brine or the salt solution reacts with limestone to form sodium carbonate and calcium chloride as per the following reaction:
$\text{NaCl + CaC}{{\text{O}}_{\text{3}}}\to \text{NaC}{{\text{O}}_{\text{3}}}\text{+ CaC}{{\text{l}}_{\text{2}}}$

Hence, the by-product of the reaction is calcium chloride, that is, option C.

Note:
Besides the principal by-product of the reaction, which is calcium chloride, the process has other products and by-products as well. Not all the limestone that is calcined is converted to quicklime and carbon dioxide; the residual calcium carbonate and other components of the limestone become wastes. In addition, the salt brine used by the process is usually purified to remove calcium and magnesium ions, typically to form carbonate otherwise that would form scales on the vessels otherwise. These carbonates are additional waste products.