Which of the following is an example of aryl alkyl halide ?

Options

A. p - chlorotoluence
B. Chlorobenzene
C. Allyl chloride
D. Benzyl chloride

Answer

To determine which of the following is an example of an aryl alkyl halide, we need to understand the definitions of the terms involved:

1. **Aryl Group**: An aryl group is derived from an aromatic compound, typically a benzene ring. It is characterized by a cyclic structure, planar structure, and follows the Huckel's rule of 4n + 2 π electrons.

2. **Alkyl Group**: An alkyl group is a hydrocarbon chain derived from alkanes, which are saturated hydrocarbons.

3. **Halide**: A halide refers to a compound that contains a halogen atom (like fluorine, chlorine, bromine, or iodine).

Now, we need to analyze the options provided to identify which one fits the definition of an aryl alkyl halide.

### Step-by-Step Solution:

**Step 1: Analyze the options.**
- **Option 1: Para-chloro toluene**
- Structure: A benzene ring with a chlorine atom and a methyl group (CH₃) in the para position.
- Analysis: This is an aryl halide (due to the presence of the chlorine on the benzene) but does not have an alkyl group attached to the halide. Hence, it is not an aryl alkyl halide.

- **Option 2: Chlorobenzene**
- Structure: A benzene ring with a chlorine atom attached.
- Analysis: This is purely an aryl halide, as there is no alkyl group present. Thus, it is not an aryl alkyl halide.

- **Option 3: Allyl chloride**
- Structure: A three-carbon chain with a double bond and a chlorine atom attached to the terminal carbon.
- Analysis: This compound does not contain an aryl group (no benzene structure), so it cannot be classified as an aryl alkyl halide.

- **Option 4: Benzyl chloride**
- Structure: A benzene ring with a CH₂Cl group attached.
- Analysis: Here, the benzene ring is the aryl group, the CH₂ is the alkyl group, and Cl is the halide. This fits the definition of an aryl alkyl halide.

**Step 2: Conclusion**
The correct answer is **Option 4: Benzyl chloride**, as it contains both an aryl group (benzene) and an alkyl group (CH₂) with a halide (Cl).