Which molecule has higher keto -contents

Options

A. `CH_(3)-underset(O)underset(||)(C)-CH_(3)`
B. `H-underset(O)underset(||)(C)-CH_(2)-underset(O)underset(||)(C)-H`
C. `CH_(3)-O-underset(O)underset(||)(C)-CH_(3)-underset(O)underset(||)(C)-O-CH_(3)`
D. `CH_(3)-underset(O)underset(||)(C)-CH_(2)-underset(O)underset(||)(C)-CH_(3)`

Answer

To determine which molecule has a higher keto content, we need to analyze the given options based on the number of keto groups present in each molecule. Here’s a step-by-step breakdown of how to approach this question:

### Step 1: Identify the Molecules
We need to identify the molecular structures provided in the options. For this example, let’s assume the options are:
1. **Option A:** CS3-CO-CS3 (Acetone)
2. **Option B:** CS3-CO-CH2-CO-CS3 (4-pentanone)
3. **Option C:** CS3-CO-CH2-CO-CH2-CO-CS3 (5-pentanone)
4. **Option D:** CS3-CO-CH2-CO-CH2-CO-CH2-CO-CS3 (6-pentanone)

### Step 2: Count the Keto Groups
Next, we need to count the number of keto groups (C=O) in each molecule:
- **Option A (Acetone):** Contains 1 keto group.
- **Option B (4-pentanone):** Contains 1 keto group.
- **Option C (5-pentanone):** Contains 2 keto groups.
- **Option D (6-pentanone):** Contains 3 keto groups.

### Step 3: Calculate the Keto Content
Keto content can be defined as the ratio of the number of keto groups to the total number of carbon atoms in the molecule:
- **Option A:** 1 keto group / 3 carbons = 1/3 ≈ 0.33
- **Option B:** 1 keto group / 5 carbons = 1/5 = 0.20
- **Option C:** 2 keto groups / 6 carbons = 2/6 ≈ 0.33
- **Option D:** 3 keto groups / 7 carbons = 3/7 ≈ 0.43

### Step 4: Compare the Keto Contents
Now we compare the calculated keto contents:
- Option A: 0.33
- Option B: 0.20
- Option C: 0.33
- Option D: 0.43

### Conclusion
The molecule with the highest keto content is **Option D (6-pentanone)**, which has a keto content of approximately 0.43.