The reaction shows which of the following mechanisms?
`CH_(3) - underset(CH_(3))underset(|)CH - Cl overset("KOH"(aq))(rarr) CH_(3) - underset(CH_(3))underset(|)(CH)-OH + Cl^(-)`

Options

A. `S_(E)`2
B. `S_(N)`2 only
C. `E_(2)`
D. `S_(N)^(2)` majorly

Answer

To determine the mechanism of the given reaction, we will analyze the reaction step by step.

### Step 1: Identify the Reactants and Products
The reaction involves a haloalkane (specifically, a secondary haloalkane) and an aqueous solution of KOH. The reactant is CH₃-CH(Cl)-CH₃, and the product is CH₃-CH(OH)-CH₃ along with Cl⁻.

**Hint:** Look at the structure of the reactants to identify the type of haloalkane involved.

### Step 2: Analyze the Reaction Conditions
The presence of KOH (a strong base) suggests that it can act as a nucleophile. In this case, the hydroxide ion (OH⁻) is the nucleophile that will attack the carbon atom bonded to chlorine.

**Hint:** Consider the role of the nucleophile in the reaction and how it interacts with the haloalkane.

### Step 3: Mechanism Type
In this reaction, the hydroxide ion (OH⁻) attacks the carbon atom that is bonded to chlorine. Since the carbon is secondary, the reaction can proceed via an SN2 mechanism, where the nucleophile attacks from the opposite side of the leaving group (Cl) leading to a simultaneous bond formation and bond breaking.

**Hint:** Recall the characteristics of SN1 and SN2 mechanisms. SN2 involves a single concerted step, while SN1 involves a two-step process.

### Step 4: Determine the Leaving Group
Chlorine (Cl) is a good leaving group and will leave as Cl⁻ when the nucleophile attacks. This supports the SN2 mechanism since the reaction proceeds with the inversion of configuration at the carbon center.

**Hint:** Think about the stability of the leaving group and how it affects the mechanism.

### Step 5: Conclusion
The reaction follows an SN2 mechanism due to the nature of the substrate (secondary haloalkane), the strong nucleophile (OH⁻), and the fact that the reaction involves a concerted mechanism with inversion of configuration.

**Final Answer:** The mechanism followed by this reaction is SN2.