Level 2

An allotrope of carbon, which exhibits only two types of $\mathrm{C}-\mathrm{C}$ bond distance of $143.5 \mathrm{pm}$ and $138.3 \mathrm{pm},$ is:

Among ${\mathrm{NH}}_3, {\mathrm{BCl}}_3, {\mathrm{Cl}}_2$ and ${\mathrm{N}}_2$, the compound that does not satisfy the octet rule is:

The number of $\mathrm{P}-\mathrm{H}$ bond$\left(\mathrm{s}\right)$ in ${\mathrm{H}}_3{\mathrm{PO}}_2, {\mathrm{H}}_3{\mathrm{PO}}_3$ and ${\mathrm{H}}_3{\mathrm{PO}}_4$, respectively, are:

The ${\mathrm{pK}}_{\mathrm{a}}$ of oxoacids of chlorine in water follows the order:

The Lewis acid strength of ${\mathrm{BBr}}_3, {\mathrm{BCl}}_3$ and ${\mathrm{BF}}_3$ is in the order:

Which of the following halides is the least stable and has doubtful existence?

Amongst ${\mathrm{NH}}_3, {\mathrm{PH}}_3, {\mathrm{AsH}}_3$ and ${\mathrm{SbH}}_3$, the one with the highest boiling point is:

Methyl chloride reacts with $\mathrm{X}$ at high temperature in the presence of a catalyst $\mathrm{Y}$ to give ${\mathrm{Me}}_2{\mathrm{SiCl}}_2$ as one of the products. The compound can also be formed by reaction of silicon tetrachloride with an organometallic reagent, $\mathrm{Z}$. $\mathrm{X}, \mathrm{Y}$, and $\mathrm{Z}$ respectively, are