Question

Assertion (A): Dilute sulphuric acid is a stronger electrolyte than concentrated sulphuric acid.

Reason (R): Dilute sulphuric acid has a higher concentration of mobile ions.

Options

• (A) is true but (R) is false.

• (A) is false but (R) is true.

• Both (A) and (R) are true and (R) is the correct explanation of (A).

• Both (A) and (R) are true, but (R) is not the correct explanation of (A).

Answer 1

Both (A) and (R) are true and (R) is the correct explanation of (A).

Explanation:

Concentrated sulphuric acid is primarily molecular and contains very few ions because there is insufficient water to facilitate ionization. When sulphuric acid is diluted, the molecules ionize almost completely in the presence of water, resulting in a much higher concentration of mobile hydronium and sulphate ions. Since the ability to conduct electricity depends on the presence of these free-moving ions, dilute sulphuric acid acts as a stronger electrolyte.

Reaction:

\[\ce{H2SO4 + 2H2O -> 2H3O+ + SO^2-_4}\]