Question

In electrophilic substitution reaction nitrobenzene react slowly while the phenol react faster than benzene why

Answer 1

Answer:

In acidic medium phenol will undergo electrophilic substitution much faster than aniline.

Explanation:

Both aniline and phenol undergo electrophilic substitution more easily than benzene in neutral conditions because of the +M effect of the NH2 and OH groups that activate the benzene ring at the ortho and para positions.

Aniline is a weak base, and in acidic medium it accepts  a proton to become the positively charged anilinium ion (C6H5NH3+), which is no longer as vulnerable to attack by an electrophile as in neutral medium.

Phenol itself is acidic, and its vulnerability to electrophilic attack is not weakened in acidic medium, unlike in the case of aniline.

Answer 2

Answer:

In electrophilic substitution reaction nitrobenzene react slowly while the phenol react faster than benzene. why ?

Explanation:

• According to given question, phenol is more reactive than benzene towards electrophilic reaction (substitution).
• It is due to donation of oxygen's lone pair into the ring system increases the electron density around the ring.
• Nitrobenzene reaction is million times slower.
• Nitration of phenol occur more faster than benzene because phenol is more easily nitrated because the presence of -OH group in phenol.
• Due to presence of electron, nitrobenzene reacts slower than benzene in electrophilic substitution reaction.
• It is also the slowest step of the reaction.

Hence, in electrophilic substitution reaction nitrobenzene react slowly while the phenol react faster than benzene.