`CH_(3)CHO overset(10%NaOH)underset(5^(@)C)rarr overset(heat) rarr overset(H_(2))underset(Ni)rarr (A )`,
Product (A ) of the reaction is

Options

A. propanol
B. ethanol
C. butanol
D. pentanol

Explanation

To determine the product (A) of the reaction involving CH₃CHO (acetaldehyde) with 10% NaOH at 5°C followed by heating and reduction with H₂ in the presence of Ni, we can break down the process step by step.

### Step 1: Aldol Condensation
1. **Starting Material**: The reaction begins with acetaldehyde (CH₃CHO), which has an alpha hydrogen.
2. **Base Addition**: When 10% NaOH is added, it acts as a base and deprotonates the alpha hydrogen of acetaldehyde, forming an enolate ion.
- **Enolate Formation**:
\[ \text{CH}_3\text{CHO} \xrightarrow{\text{NaOH}} \text{CH}_3\text{C}^-\text{(OH)}\text{CHO} \]
3. **Nucleophilic Attack**: The enolate ion attacks the carbonyl carbon of another acetaldehyde molecule, leading to the formation of a β-hydroxy aldehyde.
- **Formation of β-Hydroxy Aldehyde**:
\[ \text{CH}_3\text{C}^-\text{(OH)}\text{CHO} + \text{CH}_3\text{CHO} \rightarrow \text{CH}_3\text{C(OH)(CH}_3)\text{CHO} \]

### Step 2: Dehydration
4. **Heating**: Upon heating, the β-hydroxy aldehyde undergoes dehydration (loss of water) to form an α,β-unsaturated aldehyde (alkene).
- **Dehydration Reaction**:
\[ \text{CH}_3\text{C(OH)(CH}_3)\text{CHO} \xrightarrow{\text{heat}} \text{CH}_3\text{C}=\text{CHCHO} + \text{H}_2\text{O} \]

### Step 3: Reduction
5. **Reduction with H₂/Ni**: The α,β-unsaturated aldehyde is then reduced using hydrogen gas (H₂) in the presence of nickel (Ni) as a catalyst.
- **Reduction Reaction**:
\[ \text{CH}_3\text{C}=\text{CHCHO} + \text{H}_2 \xrightarrow{\text{Ni}} \text{CH}_3\text{CH}_2\text{CHO} \]
- This results in the formation of butanal (CH₃CH₂CHO).

### Final Product
Thus, the product (A) of the entire reaction sequence is **butanal (CH₃CH₂CHO)**.

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