Class 11 NEET Chemistry Some P-block Elements Questions

B(OH)3 in aqueous medium coordinates a molecule of water to form the hydrated species .In this speices B3+ ion, because of its small size, has high polarizing power thereby pulling the sigma electron charge of the coordinated O atom towards itself. The coordinated oxygen, in turn, pulls the sigma electron charge of the OH bond of the attached water molecule towards itself. This facilitates the removal of H+ ion from the O−H bond.Thus, the solution of B(OH)3 in water acts as a weak acid, and it is not a protonic acid.