Statement-I: Polar solvent slows down `S_(N^(2))` reaction.
Because Statement-II: `CH_(3)-Br` is less reactive than `CH_(3)Cl`.

Options

A. Statement-I is True, Statement-II is True, Statement-II is a correct explanation for Statement-I
B. Statement-I is True, Statement-II is True, Statement-II is NOT a correct explanation for Statement-I
C. Statement-I is True, Statement-II is False.
D. Statement-I is False, Statement-II is True.

Answer

To analyze the given statements, we will evaluate each statement individually and then determine their relationship.

### Step 1: Analyze Statement-I
**Statement-I:** Polar solvent slows down `S_(N^(2))` reaction.

- **Explanation:** The `S_(N^(2))` mechanism involves a nucleophile attacking an electrophile in a single concerted step. Polar solvents, especially protic solvents, can stabilize the nucleophile through solvation. This solvation makes it harder for the nucleophile to attack the substrate, thus slowing down the reaction. In contrast, `S_(N^(2))` reactions are favored in polar aprotic solvents, which do not solvate the nucleophile as effectively, allowing it to remain reactive.

**Conclusion:** Statement-I is **True**.

### Step 2: Analyze Statement-II
**Statement-II:** `CH_(3)-Br` is less reactive than `CH_(3)-Cl`.

- **Explanation:** The reactivity of alkyl halides in `S_(N^(2))` reactions depends on the bond dissociation energies of the carbon-halogen bonds. The bond dissociation energy for `C-Br` is lower than that for `C-Cl`, meaning that `CH_(3)-Br` has a weaker bond and is more reactive than `CH_(3)-Cl`. Therefore, `CH_(3)-Br` is actually more reactive, not less.

**Conclusion:** Statement-II is **False**.

### Step 3: Determine the Relationship Between the Statements
- Statement-I is True.
- Statement-II is False.

Since Statement-I is true but Statement-II is false, Statement-II does not correctly explain Statement-I.

### Final Conclusion
- Statement-I is true.
- Statement-II is false.
- Therefore, the correct answer is that Statement-I is true and Statement-II is false.

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