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:

In dilute H₂SO₄, the acid ionises to a much greater extent \[\ce{(giving free H+ and HSO^−_4/SO^2−_4)}\] and the solution has many mobile ions, so it conducts well (strong electrolyte). In concentrated H₂SO₄ the lack of water suppresses ionisation and the high viscosity reduces ion mobility, so the electrical conductivity is lower. This difference (dilute = strong electrolyte; concentrated = weaker electrolyte) is stated in the notes.