Dilute aqueous solution of ........ acid is used as antibiotic. 

Correct Lewis acidity order of $BX_3$ is

$B{\left( {OH} \right)_3} + NaOH \to NaB{O_2} + Na\left[ {B{{\left( {OH} \right)}_4}} \right] + {H_2}O$ 

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

Assertion : $Al(OH)_3$ is insoluble in $NH_4OH$ but soluble in $NaOH$ .

Reason : $NaOH$ is strong alkali.

Give increasing order of group $13$ elements for atomic radius. 

Among the following, the correct statement(s) is(are)

$[A]$ $\mathrm{A} 1\left(\mathrm{CH}_3\right)_3$ has the three-centre two-electron bonds in its dimeric structure

$[B]$ $\mathrm{BH}_3$ has the three-centre two-electron bonds in its dimeric structure

$[\mathrm{C}] \mathrm{AlCl}_3$ has the three-centre two-electron bonds in its dimeric structure

$[D]$ The Lewis acidity of $\mathrm{BCl}_5$ is greater than that of $\mathrm{AlCl}_5$