Question

Which of the following statement (s) about $H_{3}B{O}_3$ is / are correct?

• A. It is a strong tribasic acid.
• B. It is prepared by acidifying an aqueous solution of borax
• C. It has a layer structure in which planar $B{O}_3$ units are joined by hydrogen bonds.
• D. It does not act as proton donor as it acts as a lewis acid by accepting lone pair hydroxyl ions.

Answer 1

Answer: (B), (C), (D)

It does not act as proton donor as it acts as a lewis acid by accepting lone pair hydroxyl ions.

It has a layer structure in which planar $B{O}_3$ units are joined by hydrogen bonds.

Preparation: Precipitated by acidifying an aqueous solution of borax.
$N{a}_2{B}_4{O}_7+2HCl+5H_{2}O\to 2NaCl+4H_{3}B{O}_3$

It is not a protonic acid but acts as a Lewis acid by accepting electrons from a hydroxyl ion.
$B(OH{)}_3+2H_{2}O\to B(OH{)}_4^{-}+H_3{O}^{+}$

Hence option b, c, d are correct.