Which one of the following on oxidation will not give a carboxylic acid with the same number of carbon atoms ?

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`

Answer

To determine which compound will not yield a carboxylic acid with the same number of carbon atoms upon oxidation, we will analyze each option provided in the question step by step.

### Step 1: Analyze Option 1 - Acetone (CH3COCH3)
- Acetone is a ketone and has the structure CH3COCH3.
- Ketones are generally resistant to oxidation under mild conditions. However, under drastic conditions, they can undergo cleavage.
- When oxidized, acetone can break down to form acetic acid (CH3COOH) and formic acid (HCOOH).
- Count the carbon atoms:
- Reactant (Acetone): 3 carbons (C3)
- Products (Acetic Acid + Formic Acid): 2 carbons (C2) and 1 carbon (C1).
- Since the number of carbon atoms in the product is less than in the reactant, this option satisfies the condition.

### Step 2: Analyze Option 2 - CCl3CH2CHO
- This compound is a chlorinated aldehyde.
- Upon oxidation, it will convert to CH2COOH (carboxylic acid) while retaining the three chlorine atoms.
- Count the carbon atoms:
- Reactant: 3 carbons (C3)
- Product: 3 carbons (C3).
- The number of carbon atoms remains the same, so this option does not satisfy the condition.

### Step 3: Analyze Option 3 - CH3CH2OH (Ethanol)
- Ethanol is a primary alcohol.
- Upon oxidation, ethanol first converts to acetaldehyde (CH3CHO) and then to acetic acid (CH3COOH).
- Count the carbon atoms:
- Reactant: 2 carbons (C2)
- Product: 2 carbons (C2).
- The number of carbon atoms remains the same, so this option does not satisfy the condition.

### Step 4: Analyze Option 4 - CH3CH2CHO (Propionaldehyde)
- Propionaldehyde is also a primary aldehyde.
- Upon oxidation, it will convert to propionic acid (CH3CH2COOH).
- Count the carbon atoms:
- Reactant: 3 carbons (C3)
- Product: 3 carbons (C3).
- The number of carbon atoms remains the same, so this option does not satisfy the condition.

### Conclusion:
Based on the analysis, **Option 1 (Acetone)** is the only compound that, upon oxidation, does not yield a carboxylic acid with the same number of carbon atoms.

### Final Answer:
**Acetone (Option 1)** will not give a carboxylic acid with the same number of carbon atoms upon oxidation.

---