Question

Assertion: Acidity of a base is due to the number of hydroxyl ions present in it.

Reason: Calcium hydroxide is a diacid base.

• A. Both assertion and reason are correct and the reason is the correct explanation of the assertion.
• B. Both assertion and reason are correct but the reason is not the correct explanation of the assertion.
• C. The assertion is correct but the reason is incorrect
• D. The assertion is incorrect but the reason is correct

Answer 1

The correct option is B

Both assertion and reason are correct but the reason is not the correct explanation of the assertion.

Explanation for the assertion statement:

1. The acidity of a base is the number of hydroxyl ions (OH^-) that can be produced per molecule by the base in an aqueous solution.
2. Therefore, the assertion is correct.

Explanation for the reason statement:

The reason is correct as-

1. Calcium hydroxide (Ca(OH)₂) is a diacid base as it produces 2 hydroxyl ions per molecule in an aqueous solution.
2. $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\left(\mathrm{aq}\right)\stackrel{}{\to }{\mathrm{Ca}}^{2+}\left(\mathrm{aq}\right)+2{\mathrm{OH}}^{-}\left(\mathrm{aq}\right)$

Thus, the assertion and the reason both are correct.

Therefore, Option B is correct.