B(OH)_(3)+NaOH to Na[B(OH)_(4)] (aq). Then addition of which of the following proceeds the reaction in the forward direction ?

B(OH)_(3)+NaOH to Na[B(OH)_(4)] (aq). Then addition of which of the fo

1.	B(OH)_(3)+NaOH to Na[B(OH)_(4)] (aq). Then addition of which of the following proceeds the reaction in the forward direction ?
Answer» Cis-`1,2` diol Trans `1,2` diol Borax `Na_(2)HPO_(4)` Solution :If certain organic polyhydroxy compounds such as glycerol, manitol or sugars are added to the titration mixture, then `B(OH)_(3)` behaves as a STRONG monobasic acid and it can be now titrated with `NaOH` and the end point is detected using phenolphthalein as indicator `(pH=8.3-10.0)`. The added compound must be a cis-diol, to enhance the acid properties.The cis-diol forms very STABLE complex with the `[B(OH)_(4)]^(-)`, thus removing it from solution.The reaction is reversible and thus removal of one of the products swift the equilibrium in the forward direction and thus all the `B(OH)_(3)` REACTS with `NaOH`, in effect it ACTS as a strong acid in the presence of the cis-diol. `B(OH)_(3)+NaOH to Na[B(OH)_(4)]+NaBO_(2)+2H_(2)O`.