The order of reactivity of `CH_(3)CHO, CH_(3)COC_(2)H_(5) and CH_(3)COCH_(3) ` is

Options

A. `CH_(3)CHO gt CH_(3)COCH_(3) gt CH_(3)COC_(2)H_(5)`
B. `C_(2)H_(5)COCH_(3) gt CH_(3)COCH_(3) gt CH_(3)CHO`
C. `CH_(3)COCH_(3) gt CH_(3)CHO gt C_(2)H_(2)COCH_(3)`
D. `CH_(3)COCH_(3) gt C_(2)H_(5)COCH_(3) gt CH_(3)CHO`

Explanation

To determine the order of reactivity of the compounds \( CH_3CHO \) (acetaldehyde), \( CH_3COC_2H_5 \) (ethyl methyl ketone), and \( CH_3COCH_3 \) (acetone), we need to analyze their stability and how that relates to their reactivity.

### Step 1: Identify the Compounds
- **Compound 1**: \( CH_3CHO \) (Acetaldehyde)
- **Compound 2**: \( CH_3COC_2H_5 \) (Ethyl Methyl Ketone)
- **Compound 3**: \( CH_3COCH_3 \) (Acetone)

### Step 2: Understand Reactivity and Stability
Reactivity is inversely proportional to stability. This means that the less stable a compound is, the more reactive it will be.

### Step 3: Analyze the Stability of Each Compound
1. **Acetaldehyde (\( CH_3CHO \))**:
- It has a carbonyl group (C=O) and is an aldehyde. Aldehydes are generally more reactive than ketones due to less steric hindrance and the presence of a hydrogen atom attached to the carbonyl carbon.

2. **Ethyl Methyl Ketone (\( CH_3COC_2H_5 \))**:
- This is a ketone with two alkyl groups. The presence of the ethyl group provides a +I (inductive) effect, which stabilizes the positive charge that can develop during reactions.

3. **Acetone (\( CH_3COCH_3 \))**:
- Acetone is also a ketone, but it has two methyl groups. The +I effect from two methyl groups is significant, making acetone more stable than ethyl methyl ketone.

### Step 4: Compare Stability
- **Stability Order**:
- \( CH_3COCH_3 \) (most stable, due to two +I effects from methyl groups)
- \( CH_3COC_2H_5 \) (less stable than acetone, due to one +I effect)
- \( CH_3CHO \) (least stable, as it is an aldehyde)

### Step 5: Determine the Reactivity Order
Since reactivity is inversely proportional to stability:
- **Reactivity Order**:
- \( CH_3CHO > CH_3COC_2H_5 > CH_3COCH_3 \)

### Final Answer
The order of reactivity is:
\[ CH_3CHO > CH_3COC_2H_5 > CH_3COCH_3 \]