In which of the following the number of carbon atoms are not the same when carboxylic acid is obtained by oxiadation ?

Options

A. `CH_(3)COCH_(3)`
B. `C Cl_(3)CH_(2)CHO`
C. `CH_(3)CH_(2)CH_(2)OH`
D. `CH_(3)CH_(2)CHO`

Explanation

To solve the question of which carbonyl compound, when oxidized, results in a carboxylic acid with a different number of carbon atoms, we can analyze the oxidation of various carbonyl compounds: aldehydes, ketones, and alcohols.

### Step-by-Step Solution:

1. **Understanding Oxidation of Carbonyl Compounds**:
- When carbonyl compounds (aldehydes and ketones) are oxidized, they can form carboxylic acids.
- Generally, aldehydes can be oxidized to carboxylic acids without losing any carbon atoms.
- Ketones, on the other hand, can be oxidized but may lead to the cleavage of the carbon chain, resulting in carboxylic acids that have fewer carbon atoms than the original ketone.

2. **Analyzing Options**:
- Let's consider the options provided (though not listed here, we will analyze typical examples):
- **Aldehydes**: Oxidation of an aldehyde (e.g., ethanol) to acetic acid retains the same number of carbon atoms (2 → 2).
- **Ketones**: Oxidation of a ketone (e.g., acetone) can lead to the formation of two different carboxylic acids, resulting in a loss of one carbon atom (3 → 2).
- **Alcohols**: Oxidation of primary alcohols to aldehydes and then to carboxylic acids also retains the same number of carbon atoms (e.g., ethanol to acetic acid).

3. **Conclusion**:
- The only scenario where the number of carbon atoms is not the same after oxidation is with ketones. For example, acetone (3 carbon atoms) can be oxidized to form acetic acid (2 carbon atoms) and formic acid (1 carbon atom), resulting in a total loss of carbon atoms.

### Final Answer:
The answer is **Ketones**, as they can lose a carbon atom during oxidation.