Ok, I read stuff up and came up with this:
Aniline dissolves in dil HCl with this reaction:
[itex]C_6H_5NH_2+HCl\rightarrow C_6H_5NH_3^{+}Cl^{-}[/itex]
Nitrobenzene does not dissolve in it but forms the bottom layer in the mixture,so the upper layer can be separated out.
But what next?Am I on the right track?
(and what happens when phenol is also present in the same mixture?)