(HCl—ZnCl2) is lucas reagent, lucas reagent react with alcohol however it does not react with primary alcohol but readily gives turbidity with tertiary alcohols.
a) Reaction with (HCl—ZnCl2):
Butan-1-ol is primary alcohol thus no reaction occur.
where as 2-methyl butan-2-ol is tertiary alcohol, it forms 2-chloro-2-methylbutane.
Resonance structures of ortho nitro phenol:
Thus, presence of nitro group at ortho and para position increase the acidic character.