The reagent used for the separation of Acetadehyde from acetophenone is

Options

A. `NaHSO_(3)`
B. `CH_(3)COCH_(2)CH_(2)Br`
C. `CH_(3)CH_(2)Br`
D. `CH_(3)CH_(2)CH_(2)Br`

Explanation

To solve the problem of separating acetaldehyde from acetophenone, we need to identify a reagent that selectively reacts with one of the compounds in the mixture.

### Step-by-Step Solution:

1. **Identify the Structures**:
- Acetaldehyde (CH3CHO) has the structure:
```
H O
\ ||
C--C
/
H
```
- Acetophenone (C6H5COCH3) has the structure:
```
O
||
C--C
/ \
H C6H5
```

2. **Choose a Suitable Reagent**:
- We need a reagent that will react with acetaldehyde but not with acetophenone. A suitable reagent for this purpose is sodium bisulfite (NaHSO3).

3. **Reaction with Sodium Bisulfite**:
- When acetaldehyde reacts with sodium bisulfite, it forms a bisulfite adduct, which is a white precipitate:
```
CH3CHO + NaHSO3 → CH3CSO3Na + H2O
```
- This reaction occurs because acetaldehyde has a reactive carbonyl group that can undergo nucleophilic addition.

4. **No Reaction with Acetophenone**:
- Acetophenone, due to its steric hindrance from the phenyl group, does not react with sodium bisulfite. The carbonyl carbon is less accessible for nucleophilic attack, so no precipitate forms from acetophenone.

5. **Separation**:
- The formation of the white precipitate from acetaldehyde allows for the separation of the two compounds. The precipitate can be filtered out, leaving acetophenone in solution.

6. **Recovery of Acetaldehyde**:
- The bisulfite adduct can be converted back to acetaldehyde by treating it with an acid (e.g., HCl):
```
CH3CSO3Na + HCl → CH3CHO + NaCl + H2O
```

### Conclusion:
The reagent used for the separation of acetaldehyde from acetophenone is sodium bisulfite (NaHSO3).

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