Question

Which of the following is only acidic in nature :

• A. Be(OH)2
• B. Mg(OH)2
• C. B(OH)3
• D. Al(OH)3

Answer 1

Answer: (C)

B(OH)3

Answer 2

B(OH)3 + 2HOH $\rightleftharpoons$ [B(OH)4]– + H3O+.

In aqueous solution the boron completes its octet by accepting OH– from water molecules. It therefore function as a weak monobasic lewis acid.