Benzyl bromide on reaction with magnesium in the presence of dry ether gives $'X'$. $'X'$ on reaction with ethanol gives $'Y'$. Then the compound $Y$ is

Which one of the following compounds will give an enantiomeric pair on treatment with $HOH$?

If all the nucleophilic substitution reactions at saturated carbon atoms in the above sequence of reactions follow $S_N2$ mechanism, then $\underline{E}$ and $\underline{E}$ will be respectively,

Which of the following compounds will give a racemic mixture by $S_N1$ reaction?

Consider the following anions:
$(I)$ $CF_3SO_3^-$
$(II)$ $C_6H_5SO_3^-$
$(III)$ $C_6H_5O^-$
$(IV)$ $CH_3COO^-$
When attached to $sp^3$ hybridized carbon,their leaving group ability in nucleophilic substitution reaction decreases in the order:

Which of the following haloalkanes would undergo $S_{N}2$ reaction at the fastest rate?