The Reduction Of 3-Pentanone With Hydrogen In The Presence Of A Nickel Catalyst Will Yield
2-Pentene.
3-Pentanol
Pentanaldehyde.
Diethyl Alcohol
Pentane
The Correct Answer and Explanation is :
The correct answer is 3-Pentanol.
Explanation:
The reduction of 3-pentanone (C5_5H10_{10}O) with hydrogen (H2_2) in the presence of a nickel (Ni) catalyst follows a standard catalytic hydrogenation process. Let’s break it down step by step.
1. Understanding 3-Pentanone:
3-Pentanone is a ketone with the molecular formula C5_5H10_{10}O. Its structure is: CH3CH2COCH2CH3CH_3CH_2COCH_2CH_3
This means the carbonyl (C=O) group is located at the third carbon.
2. What Happens in Catalytic Hydrogenation?
- Hydrogenation is a reduction reaction, where hydrogen gas adds to the carbonyl group.
- In the presence of a nickel catalyst (which facilitates the breaking of H2_2 bonds), hydrogen atoms reduce the carbonyl (C=O) group to a hydroxyl (-OH) group.
- The ketone (3-pentanone) gets reduced to a secondary alcohol (3-pentanol).
3. The Reaction:
CH3CH2COCH2CH3+H2→NiCH3CH2CHOHCH2CH3CH_3CH_2COCH_2CH_3 + H_2 \xrightarrow{Ni} CH_3CH_2CHOHCH_2CH_3
The C=O bond is converted into a C-OH bond, forming 3-pentanol (C5_5H12_{12}O).
4. Why Not the Other Options?
- 2-Pentene: Requires elimination, not reduction.
- Pentanaldehyde (Pentanal): Aldehydes are obtained from partial oxidation, not reduction of ketones.
- Diethyl alcohol (Ethanol): Ethanol is unrelated to this reaction.
- Pentane: Complete hydrogenation of a ketone to an alkane is not typical under these conditions.
Thus, 3-Pentanol is the correct answer.