Question

B(OH)3 + NaOH ⇋ NaBO2 + Na[B(OH)4] + H2O

How can this reaction is made to proceed in forward direction?

(a) Addition of cis 1, 2 diol

(b) Addition of borax

(c) Addition of trans 1, 2 diol

(d) Addition of Na2HPO4.

Answer 1

The correct option (a) Addition of cis 1, 2 diol

Explanation:

B(OH)3 + NaOH ⇋ NaBO2 + Na[B(OH)4] + H2O

This reaction is reversible reaction because sodium metaborate, Na+[B(OH)4]- formed by the reaction between B(OH)3 and NaOH gets hydrolysed to regenerate B(OH)3 and NaOH

If, some quantity of polyhydroxy compounds like cis- 1, 2-diol, catechol, glycerol etc is added to the reaction mixture then the B(OH)3 combines with such polyhydroxy compounds to give chelated complex compound. Due to complex compound formation, stability increases and due to higher stability of complex, reaction moves in forward direction.