Question

Orthoboric acid behaves as weak monobasic acid in water giving $H_3{O}^{+}$ and

• A. $H_{2}B{O}_2^{-}$
• B. $H_{2}B{O}_3^{-}$
• C. $\left[B\right(OH{)}_4{]}^{-}$
• D. $\left[B\right(OH{)}_4{]}^{+}$

Answer 1

The correct option is C $\left[B\right(OH{)}_4{]}^{-}$

In aqueous solutions, the B atom​ completes its octet by accepting​ $O{H}^{–}$ from $H_{2}O$ molecules​.
$B(OH{)}_3+2H_{2}O\rightleftharpoons [B(OH{)}_4{]}^{-}+H_3{O}^{+}$
Therefore, it functions as a​ lewis acid and not as a​ proton donor like most acids​. Since it behaves as a weak acid​. Hence, the correct answer is option (c).