Question

Classify the following salts as acidic/basic/ neutral salts and show the chemical equation of the neutralisation reaction to get these salts.
A.Aluminium chloride
B.Sodium sulphate

Answer 1

Hint: Neutralization is a chemical reaction between an acid and a base to form corresponding salt and water. The quantities of the acid and base must be equimolar. The pH of the salt formed depends upon the strength of the acid. The universal pH scale ranges from 1 to 14.

Complete answer:
We know that to form a salt, a reaction between the acid and the base is imperative.
Firstly, let’s see the classification of Ammonium chloride.
Ammonium chloride is formed by the reaction between Hydrochloric acid and Aluminium hydroxide. However, HCl is a strong acid and Aluminium hydroxide is a weak base. Thus, the resultant Aluminium chloride solution will be acidic because the acid in the reactant is a strong one. The salt solution of Aluminium chloride is mildly acidic as it reacts with water. The solution then turns acidic and shows acidic behaviour with the litmus paper.
The balanced chemical equation of the neutralisation reaction to getting Ammonium chloride is as follows:
$Al{{\left( OH \right)}_{3}}\text{ + 3HCl }\to \text{ AlC}{{\text{l}}_{3}}\text{ + 3}{{\text{H}}_{2}}O$
Secondly, let’s see the classification of Sodium sulphate.
Sodium sulphate is formed by the reaction between Sulphuric acid and Sodium hydroxide. Here, both the reactants are strong. Sulphuric acid is a strong acid and Sodium hydroxide is a strong base. When a strong acid and a strong base react, the resultant salt is neutral. Thus, Sodium sulphate is a neutral salt.
The balanced chemical equation of the neutralisation reaction to getting Sodium sulphate is as follows:
$2NaOH\text{ + }{{\text{H}}_{2}}S{{O}_{4\text{ }}}\to \text{ N}{{\text{a}}_{2}}S{{O}_{4}}\text{ + 2}{{\text{H}}_{2}}O$

Note:
Remember that the pH of the acid is the major factor in determining the nature of the salt. However, if both the acid and base are of the same strength (nature), the resultant salt will be neutral. The pH of an acid is less than 7 and more than 1 whereas the pH of a base is more than 7 and less than 14. Also, the pH of a neutral solution is at 7.