Question

Arrange the following compounds in increasing order of rate of aromatic electrophilic substitution reaction:

• A. (a)<(b)<(c)
• B. (b)<(c)<(a)
• C. (c)<(a)<(b)
• D. (c)<(b)<(a)

Hint:

Remember that groups like -OH and -NH\(_2\) activate the aromatic ring by donating electron density, whereas -NO\(_2\) and -COOH deactivates it by withdrawing electron density.

Answer 1

The Correct Option is A

- Benzene becomes more reactive towards electrophilic aromatic substitution (EAS) when an electron-donating group (-OH, -NH\(_2\)) is attached to the benzene ring.

- Benzene with electron-withdrawing groups (-NO\(_2\), -COOH) decreases the reactivity, as it deactivates the ring towards electrophilic attack. Thus, the order is: \[ \text{(a)<(b)<(c)} \]