The conversion `CH_(3)CH_(2)CHO "––––"rarr CH_(3)CH_(2)CH_(2)`OH can not be affected by:

Options

A. `NaBH_(4)`
B. Zn / HCl / Hg
C. `H_(2)`/Ni
D. Na + alcohol

Answer

To solve the question regarding the conversion of propanal (CH₃CH₂CHO) to propanol (CH₃CH₂CH₂OH), we need to identify which reagent does not facilitate this conversion. The conversion involves the reduction of an aldehyde to an alcohol.

### Step-by-Step Solution:

1. **Identify the Reactants and Products**:
- The starting compound is propanal (CH₃CH₂CHO), which is an aldehyde.
- The product is propanol (CH₃CH₂CH₂OH), which is a primary alcohol.

2. **Understand the Reaction Type**:
- The reaction is a reduction process where the aldehyde is converted into an alcohol.
- Aldehydes can be reduced to alcohols using various reducing agents.

3. **List Possible Reducing Agents**:
- Common reducing agents include:
- Lithium aluminium hydride (LiAlH₄)
- Sodium borohydride (NaBH₄)
- Hydrogen gas (H₂) in the presence of a catalyst like nickel (Ni)
- Sodium metal in alcohol (Na + alcohol)

4. **Evaluate Each Option**:
- **Option 1: Sodium Borohydride (NaBH₄)**: This is a reducing agent that can convert aldehydes to alcohols. Thus, it affects the conversion.
- **Option 2: Zinc Amalgam in Presence of HCl**: This is used in Clemensen reduction, which converts carbonyl compounds (like aldehydes) to alkanes by removing the oxygen. Therefore, it does not facilitate the conversion to alcohol.
- **Option 3: Nickel in Presence of Hydrogen**: This is a reducing agent that can reduce aldehydes to alcohols. Thus, it affects the conversion.
- **Option 4: Sodium + Alcohol**: This also acts as a reducing agent and can facilitate the conversion of aldehydes to alcohols.

5. **Conclusion**:
- The reagent that does not affect the conversion of propanal to propanol is **Zinc Amalgam in Presence of HCl** (Option 2).

### Final Answer:
The conversion `CH₃CH₂CHO → CH₃CH₂CH₂OH` cannot be affected by **Zinc Amalgam in Presence of HCl**.

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