Which one of the following compounds is more reactive towards `S_(N)2` reaction and why ? `CH_3CH(Cl) CH_2CH_3 or CH_3CH_2CH_2Cl`

Explanation

To determine which compound is more reactive towards an \( S_N2 \) reaction between \( CH_3CH(Cl)CH_2CH_3 \) (which we will refer to as compound A) and \( CH_3CH_2CH_2Cl \) (which we will refer to as compound B), we need to analyze the structure and the type of halide each compound represents.

### Step-by-Step Solution:

1. **Identify the Type of Halide**:
- For compound A \( (CH_3CH(Cl)CH_2CH_3) \):
- The carbon atom bonded to the chlorine atom (Cl) is attached to two other carbon atoms (one on each side). This makes it a **secondary halide**.
- For compound B \( (CH_3CH_2CH_2Cl) \):
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