Toluene react with a halogen in the presence of iron (III) chloride giving ortho andpara halo compounds. The reactions is

Options

A. electrophilic elimination reaction
B. electrophilic substitution reaction
C. free radical addition reaction
D. nucleophilic substitution reaction

Explanation

To solve the problem of how toluene reacts with halogen in the presence of iron (III) chloride to yield ortho and para halo compounds, we can break down the reaction into several steps:

### Step-by-Step Solution:

1. **Identify the Reactants:**
- The main reactant is toluene (C6H5CH3), which contains a methyl group (–CH3) attached to a benzene ring.
- The halogen used in the reaction is typically chlorine (Cl2), and iron (III) chloride (FeCl3) acts as a catalyst.

2. **Role of Iron (III) Chloride:**
- Iron (III) chloride (FeCl3) is a Lewis acid and helps in generating the electrophile (Cl+). It interacts with Cl2 to form Cl+ and Cl-.
- The reaction can be represented as:
\[ \text{Cl}_2 + \text{FeCl}_3 \rightarrow \text{Cl}^+ + \text{FeCl}_4^- \]

3. **Formation of the Electrophile:**
- The generated Cl+ ion is a strong electrophile that can attack the electron-rich benzene ring of toluene.

4. **Electrophilic Attack on Toluene:**
- Toluene has a methyl group, which is an electron-donating group. This increases the electron density on the ortho and para positions of the benzene ring.
- The Cl+ can attack the benzene ring at either the ortho (adjacent) or para (opposite) positions relative to the methyl group.

5. **Formation of Ortho and Para Products:**
- When Cl+ attacks the ortho position, it displaces a hydrogen atom, resulting in the ortho-chlorotoluene:
\[ \text{C}_6\text{H}_5\text{CH}_3 + \text{Cl}^+ \rightarrow \text{C}_6\text{H}_4\text{Cl (ortho)}\text{CH}_3 + \text{H}^+ \]
- When Cl+ attacks the para position, it also displaces a hydrogen atom, resulting in para-chlorotoluene:
\[ \text{C}_6\text{H}_5\text{CH}_3 + \text{Cl}^+ \rightarrow \text{C}_6\text{H}_4\text{Cl (para)}\text{CH}_3 + \text{H}^+ \]

6. **Conclusion:**
- The overall reaction can be summarized as:
\[ \text{C}_6\text{H}_5\text{CH}_3 + \text{Cl}_2 \xrightarrow{\text{FeCl}_3} \text{C}_6\text{H}_4\text{Cl (ortho)}\text{CH}_3 + \text{C}_6\text{H}_4\text{Cl (para)}\text{CH}_3 + \text{H}^+ \]
- This is an example of an electrophilic aromatic substitution reaction.