Question

4. For each of the following, state whether it would undergo nitration faster, slower or at
the same rate as phenol. Explain each answer.
a. p-bromophenol
b. o-ethylphenol
c. benzene

Answer 1

a) slower

b) faster

c) slower

Explanation

Nitration is Aromatic electric substitution reaction , electron donating groups present in the ring are increasing the neucleophilicity of the ring by donating electron density through π system, thus increasing the rate of the substitution. Electron withdrawing groups present in the ring are decreasing the neucleophilicity of the ring by withdrawing electron density through π system , thus decreasing the rate of substitution.

a) p-bromophenol has bromine as deactivating group comparing to phenol , thus decreasing the rate of substitution

b) o- ethylphenol has ethyl group as activating group comparing to phenol, thus incresing the rate of substitution

c) Benzene has no activating group comparing to phenol, thus slower than phenol