Question

Aqueous solution of which of the following boron compounds will be strongly basic in nature?

• A. NaBH4
• B. LiBH4
• C. B2H6
• D. Na2B4O7

Answer 1

Answer: (D)

Na2B4O7

Answer 2

The correct answer is (D) : Na2B4O7
$Na_2B_4O_7 + 7H_2O → 2H_3BO_3 + 2Na[B(OH)_4]$
Aqueous solution of borax is buffer whose PH ≃ 9
$Na_2B_4O_7$ is borax and when it is treated with water, it forms $H_3BO_3$ and NaOH. NaOH is a strong base and $H_3BO_3$ is a weak acid. As aqueous solution of boric acid is alkaline, hence it is basic in nature.