Hydrogen gas will not reduce

Which one is used as a bye-product in Serpeck's process

Give suitable laboratory preparation for diborane.

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 $\mathrm{AlCl}_5$

In Hall’s process, the main reagent is mixed with

The function of fluorspar in the electrolytic reduction of alumina dissolved in fused cryolite $(N{a_3}Al{F_6})$ is