Question

An aqueous solution of borax that has $1\text{mol}$ of borax reacts with $2\text{mol}$ of acids. This is because of the formation of:

• A. 2 mol of $Ba(OH{)}_3$
• B. 2 mol of ${\left[Ba\right(OH{)}_4]}^{-}$ only
• C. 1 mol each of $B(OH{)}_3$ and ${\left[B\right(OH{)}_4]}^{-}$
• D. 2 mol each of ${\left[B\right(OH{)}_4]}^{-}$ and $B(OH{)}_3$, of which only ${\left[B\right(OH{)}_4]}^{-}$ reacts with acid

Answer 1

The correct option is D 2 mol each of ${\left[B\right(OH{)}_4]}^{-}$ and $B(OH{)}_3$, of which only ${\left[B\right(OH{)}_4]}^{-}$ reacts with acid

$\left[B_4{O}_5\right(OH{)}_4{]}^{2-}+5H_{2}O\rightleftharpoons \underset{\left(weakacid\right)}{2B(OH{)}_3}+\underset{\left(salt\right)}{2\left[B\right(OH{)}_4{]}^{-}}$