Question

The molecular formula of ammonium sulphate is _______?
(A) ${{\left( \text{N}{{\text{H}}_{4}} \right)}_{2}}\text{S}{{\text{O}}_{4}}$
(B) \[\text{N}{{\text{H}}_{2}}\text{S}{{\text{O}}_{4}}\]
(C) \[\text{N}{{\text{H}}_{4}}\text{S}{{\text{O}}_{4}}\]
(D) none of these

Answer 1

Hint: Ammonium sulphate is a salt containing ammonium cation and sulphate anion. The ammonium ion carries a +1 charge while sulphate ion carries a -2 charge. So, two ammonium ions will be needed to form neutral salt.

Complete step by step solution: The ammonium sulphate is produced by the treatment of sulphuric acid with ammonia gas. It is an acid-base reaction in which ammonia acts as a base and sulphuric acid acts as a strong acid. So, the acid will lose its proton which will then be accepted by the base and they form a neutral salt molecule.
The reaction involved is shown below:

The salt formed is ammonium sulphate which is composed of two molecules of ammonium ions and one molecule of sulphate ion to neutralize the overall charge of the compound.

Additional information: The ammonium sulphate salt has many applications in real life. It is used in most soil fertilizers to alkaline the soil pH and provides the nitrogen content which is very important for the production of the plant.

Hence, the correct option is (A) ${{\left( \text{N}{{\text{H}}_{4}} \right)}_{2}}\text{S}{{\text{O}}_{4}}$.

Note: Ammonium sulphate is an ionic salt and it easily dissolves in water. It is a slightly acidic salt because it is made by the reaction of a strong acid - ${{\text{H}}_{2}}\text{S}{{\text{O}}_{4}}$ (sulphuric acid) and a weak base - $\text{N}{{\text{H}}_{3}}$ (ammonia).