A solution of ( + )-2-chloro-2-phenylethane in toluene racemises slowly in the presence of small amount of ${\mathrm{SbCl}}_5,$ due to the formation of

A solution of (−)−1-chloro-1-phenylethane in toluene racemises slowly in the presence of a small amount of ${\mathrm{SbCl}}_5,$ due to the formation of carbocation. Carbocation has planar geomety. Hence, the nucleophile can attack from either side.