$A$ solution of $(-)-1-$chloro$-1-$phenylethane in toluene racemises slowly in the presence of a small amount of $SbCl_5$,due to the formation of:

An alkyl halide may be converted into an alcohol by

Observe the following reactions:
$1$. $C_6H_5-CH=CH_2 + HBr \rightarrow X$
$2$. $C_6H_5-C(CH_3)=CH_2 + HBr \rightarrow Y$
$3$. $C_6H_5-CH=CH_2 + HBr \xrightarrow{(C_6H_5COO)_2} Z$
The correct order of reactivity of $X, Y, Z$ towards $S_N1$ reaction is:

Which of the following reactants is used to obtain the compound $(A)$ shown below? (Assume that $EtO^{-}$ is used in all the reactions)

Which of the following has the shortest $C-Cl$ bond?

What are ambident nucleophiles? Explain with an example.