The correct order of reactivity towards the electrophilic substitiution of the compounds aniline(I),benzene(II) and nitro-benzene(III) is

Options

A. IIIgtIIgtI
B. IIgtIIIgtI
C. IltIIgtIII
D. IgtIIgtIII

Answer

To determine the correct order of reactivity towards electrophilic substitution for aniline, benzene, and nitrobenzene, we need to analyze how each compound interacts with electrophiles based on the electron density in their aromatic rings.

### Step-by-Step Solution:

1. **Identify the Compounds:**
- Aniline (I): C6H5-NH2
- Benzene (II): C6H6
- Nitrobenzene (III): C6H5-NO2

2. **Understand Electrophilic Substitution:**
- In electrophilic substitution reactions, an electrophile attacks the aromatic ring, and the reactivity depends on the electron density of the ring.
- The more electron-rich the aromatic ring, the more reactive it is towards electrophiles.

3. **Analyze Aniline:**
- Aniline has an amino group (NH2) which has a lone pair of electrons. This lone pair can donate electron density to the aromatic ring through resonance.
- This increases the electron density at the ortho and para positions, making aniline highly reactive towards electrophilic substitution.

4. **Analyze Benzene:**
- Benzene is a neutral compound with no electron-donating or withdrawing groups. It has moderate reactivity towards electrophiles, as it can participate in electrophilic substitution through its π-bonds.

5. **Analyze Nitrobenzene:**
- Nitrobenzene has a nitro group (NO2) which is an electron-withdrawing group. This group decreases the electron density in the aromatic ring through resonance and inductive effects.
- As a result, nitrobenzene is less reactive towards electrophilic substitution compared to benzene and aniline.

6. **Order of Reactivity:**
- Based on the analysis:
- Aniline is the most reactive due to the electron-donating effect of the amino group.
- Benzene is next, as it has moderate reactivity.
- Nitrobenzene is the least reactive due to the electron-withdrawing effect of the nitro group.
- Therefore, the correct order of reactivity towards electrophilic substitution is:
- Aniline (I) > Benzene (II) > Nitrobenzene (III)

### Final Answer:
The correct order of reactivity towards electrophilic substitution is:
**Aniline (I) > Benzene (II) > Nitrobenzene (III)**