$(+)-2-$chloro$-2-$phenylethane in toluene racemises slowly in the presence of small amount of $SbCl_5$,due to the formation of

Which of the following compounds will produce the product shown in the image upon reaction with $NaCN$ via an $S_N2$ mechanism?

Consider the reaction shown below. The number of $\pi$ electrons present in the major product '$P$' is ...... .

Alkyl halides react with $Mg$ in dry ether to form

What will be the reduction products of the following reactions:
$CHCl_3 \xrightarrow[Zn/HCl \text{ (alc.)}]{+2H}$
$CHCl_3 \xrightarrow[Zn/HCl \text{ (aq.)}]{+4H}$
$CHCl_3 \xrightarrow[Zn/H_2O]{+6H}$

Assertion $(A)$: $1-$Bromopentane reacts with $AgCN$ to give pentylisocyanide.
Reason $(R)$: $AgCN$ is mainly ionic in nature.