Question

A salt of sulphurous acid is called:
a.) Sulphate
b.) Sulphurite
c.) Sulphite.
d.) sulphide

Answer 1

To find the appropriate solution of the given question, we need to primarily understand the basic concept of oxoacids of sulphur.
The oxoacids of sulphur are the chemical compounds that generally contain sulphur, oxygen and hydrogen where sulphur is known to exhibit tetrahedral structure when coordinated with oxygen.

Complete step by step solution:
Sulphurous acid is a diprotic acid which means it ionizes two protons. In sulphurous acid, one atom is bonded to two hydroxyl groups and one oxygen atom forms a pi bond with the sulphur atom.
Being an acid, it neutralizes with a strong or weak base to form a salt just like when reacted with strong Sodium Hydroxide solution $\left( NaOH \right)$ , it forms a sodium sulphite along with release of water molecules i.e.
${{H}_{2}}S{{O}_{3}}+2NaOH\to N{{a}_{2}}S{{O}_{3}}+{{H}_{2}}O$
Thus, it is clear that a salt of sulphurous acid is called a sulphite
So, the correct answer is “Option C”.

Note: One is advised to remember that though Oxoacids of sulphur are more numerous and important than those of selenium $\left( Se \right)$ and Tellurium $\left( Te \right)$, many of the oxoacids of sulphur do not exist as free acids but are also known as anions and salts. It is also an important point to remember that there is hardly any evidence of the existence of sulphurous acid in the solution phase, the molecule can be isolated in the gaseous phase.