Assertion: H3BO3 is a weak acid. Reason: Water extracts the proton of H3BO3.

Question

Assertion: H3BO3 is a weak acid. Reason: Water extracts the proton of H3BO3. (A) If both assertion and reason are true and reason is the correct explanation of assertion. (B) If both assertion and reason are true but reason is not the correct explanation of assertion. (C) If assertion is true but reason is false. (D) If both assertion and reason are false.

Tardigrade Admin · Accepted Answer

H 3 BO 3 is a very weak monobasic acid ( K a =5.6 × 10-10) but it does not act as a proton donor. It behaves as a Lewis acid i.e., it accepts a pair of electrons from OH -ion of H 2 O. H - OH + B ( OH )3 longrightarrow[ B ( OH )4]-+ H +

Q. Assertion: $H_{3} B O_{3}$ is a weak acid.
Reason: Water extracts the proton of $H_{3} B O_{3}$ .

If both assertion and reason are true and reason is the correct explanation of assertion.

If both assertion and reason are true but reason is not the correct explanation of assertion.

If assertion is true but reason is false.

If both assertion and reason are false.

$H_{3} B O_{3}$ is a very weak monobasic acid $(K_{a} = 5.6 \times 1 0^{- 10})$ but it does not act as a proton donor. It behaves as a Lewis acid i.e., it accepts a pair of electrons from $O H^{-}$ ion of $H_{2} O$ .
$H - O H + B (O H)_{3} ⟶ [B (O H)_{4}]^{-} + H^{+}$

Q. Assertion: H3​BO3​ is a weak acid. Reason: Water extracts the proton of H3​BO3​.