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


Correct option is

Addition of cis-1, 2-diol



This reaction is reversible reaction because sodium metaborae, 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 compound like cis-1, 2-diol, catechol, glycerol etc. is added to the reaction mixture. The B(OH)3 combines with such polyhydroxy compound to give complex compound. Due to complex compound formation, stability increases and due to higher stability of complex, reaction moves in forward direction. 



H3BO3 is:


Borax is used as a cleansing agent because on dissolving in water, it gives:



A certain salt (X) gives the following tests:  

(i) Its aqueous solution is alkaline to litmus.

(ii) On strongly heating it swells to give a glassy bead

(iii) When concentrated sulphuric acid is added to a hot concentrated solution of (X), crystals of H3BO3 separate out.

Identify the colour of these crystals.