Which one is preferable reagent for given reaction ?
` R CH_(2)-X to HO - CH_(2) R`

Options

A. `(H_(2)O+KOH)`
B. `(ROH + KOH)`
C. `(ROH + KOH) // Delta`
D. `(H_(2)O + KOH )//Delta`

Explanation

To determine the preferable reagent for the reaction \( RCH_2X \rightarrow HOCH_2R \), we need to analyze the given options and the nature of the reaction.

### Step-by-Step Solution:

1. **Identify the Reaction Type**:
- The reaction involves the conversion of an alkyl halide (\( RCH_2X \)) to an alcohol (\( HOCH_2R \)). This indicates a nucleophilic substitution reaction where the halide (\( X \)) is replaced by a hydroxyl group (\( OH \)).

2. **Examine the Reagents**:
- The options provided are:
- A) \( H_2O + KOH \)
- B) \( ROH + KOH \)
- C) \( ROH + KOH \) (with heat)
- D) \( H_2O + KOH \) (with heat)

3. **Consider the Nature of the Reagents**:
- **Aqueous KOH (\( H_2O + KOH \))**: This is a strong base that provides hydroxide ions (\( OH^- \)). It favors nucleophilic substitution reactions, making it suitable for converting alkyl halides to alcohols.
- **Alcoholic KOH (\( ROH + KOH \))**: This tends to favor elimination reactions (formation of alkenes) rather than substitution, which is not suitable for this reaction.
- **Heating with Alcoholic KOH**: Heating will further promote elimination reactions, making it less favorable for producing alcohol.
- **Heating with Aqueous KOH**: While heating can sometimes help in certain reactions, in this case, the aqueous KOH alone is sufficient for the nucleophilic substitution.

4. **Conclusion**:
- The preferable reagent for the reaction \( RCH_2X \rightarrow HOCH_2R \) is **Aqueous KOH** (\( H_2O + KOH \)), as it effectively facilitates the nucleophilic substitution to form the alcohol.

### Final Answer:
The preferable reagent for the reaction is **Aqueous KOH** (\( H_2O + KOH \)).

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