Identify ( P ) and ( Q ) in the following reaction: 2 CH 3 Cl + Si   → 570   K Cu  …

When methyl chloride reacts with silicon in the presence of copper as a catalyst at a temperature $573 \mathrm{K}$ various types of methyl substituted chlorosilane of formula ${\mathrm{MeSiCl}}_3, {\mathrm{Me}}_2{\mathrm{SiCl}}_2, {\mathrm{Me}}_3\mathrm{SiCl}$ with small amount of ${\mathrm{Me}}_4\mathrm{Si}$ are formed. Hydrolysis of dimethyl dichlorosilane, ${\left({\mathrm{CH}}_3\right)}_2{\mathrm{SiCl}}_2$ followed by condensation polymerisation yields straight chain polymers.

$2{\mathrm{CH}}_3\mathrm{Cl}+\mathrm{Si} \underset{570 \mathrm{K}}{\overset{\mathrm{Cu} \mathrm{powder}}{\to }}{\left({\mathrm{CH}}_3\right)}_2{\mathrm{SiCl}}_2\underset{-2\mathrm{HCl}}{\overset{+2{\mathrm{H}}_2\mathrm{O}}{\to }}{\left({\mathrm{CH}}_3\right)}_2\mathrm{Si}{\left(\mathrm{OH}\right)}_2$