Question

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Boric acid is a weak acid
Reason R: Boric acid is not able to release \(H^+\) ion on its own. It receives \(OH^–\) ion from water and releases \(H^+\) ion.
In the light of the above statements, choose the most appropriate answer from the options given below.

• A. Both A and R are correct and R is the correct explanation of A.
• B. Both A and R are correct but R is NOT the correct explanation of A
• C. A is correct but R is not correct
• D. A is not correct but R is correct

Answer 1

The Correct Option is A

Let's evaluate the given assertion (A) and reason (R) about boric acid.

• Assertion A: Boric acid is a weak acid.
• Reason R: Boric acid is not able to release \(H^+\) ion on its own. It receives \(OH^–\) ion from water and releases \(H^+\) ion.

First, let's understand each statement:

1. Assertion A is correct. Boric acid (H₃BO₃) is indeed a weak acid. In aqueous solution, it does not dissociate into ions like typical strong acids.
2. Reason R is also correct. Boric acid acts as a Lewis acid. Instead of donating a proton (H⁺) itself, boric acid accepts an OH⁻ ion from water, and in the process, it causes the release of a proton from water as shown in the following reaction:

\(H_2O + B(OH)_3 \rightarrow B(OH)_4^- + H^+\)

This process justifies that boric acid indirectly causes the generation of H⁺ ions, explaining why it behaves as an acid in solution.

Since both the assertion and the reason are correct and the reason effectively explains why boric acid is classified as a weak acid, the appropriate answer is:

Both A and R are correct and R is the correct explanation of A.

This option correctly describes the relationship between the assertion and the reason.