More acidic than ethanol is

Options

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

Answer

To determine which compound is more acidic than ethanol, we need to analyze the stability of the conjugate bases formed when each compound loses a hydrogen ion. The acidity of a compound is related to the stability of its conjugate base; the more stable the conjugate base, the more acidic the compound.

### Step-by-Step Solution:

1. **Identify the structure of ethanol**:
Ethanol is represented as CH3CH2OH. When it loses a hydrogen ion (H+), it forms the conjugate base CH3CH2O⁻ (ethoxide ion).

2. **Analyze the first option**:
Let's say the first compound is R-CH2OH (where R is an alkyl group). When it loses H+, the negative charge will be on the carbon atom (R-CH2O⁻). Since carbon is less electronegative than oxygen, the negative charge on carbon is less stable than on oxygen. Therefore, this compound is **not more acidic than ethanol**.

**Hint**: Check the electronegativity of the atom holding the negative charge in the conjugate base.

3. **Analyze the second option**:
Consider the compound CH3C(=O)OCH2CH3 (an ester). The hydrogen adjacent to the carbonyl group can be acidic. When it loses H+, the conjugate base will have a negative charge on the carbon atom (CH3C(=O)OCH2⁻). Although there is some stabilization due to resonance, the negative charge is still on carbon, making it less stable than the ethoxide ion. Thus, this compound is **not more acidic than ethanol**.

**Hint**: Look for resonance stabilization and the location of the negative charge.

4. **Analyze the third option**:
The compound CH3COCH2COCH3 (a diketone) has hydrogen atoms that are highly acidic due to the presence of carbonyl groups on both sides. When a hydrogen ion is removed, the conjugate base formed (CH3C(=O)CH⁻C(=O)CH3) can stabilize the negative charge through resonance from both carbonyl groups. This conjugate base is more stable than the ethoxide ion, indicating that this compound is **more acidic than ethanol**.

**Hint**: Consider the effect of multiple resonance structures on the stability of the conjugate base.

5. **Analyze the fourth option**:
For the compound CH3COCH3 (acetone), when it loses H+, the conjugate base formed will have a negative charge on the carbon (CH3C(=O)CH2⁻). Similar to the previous analyses, while there is some resonance stabilization, the negative charge on carbon is less stable than on oxygen. Therefore, this compound is **not more acidic than ethanol**.

**Hint**: Remember that the location of the negative charge affects the overall stability of the conjugate base.

### Conclusion:
The compound that is more acidic than ethanol is **option 3 (CH3COCH2COCH3)**.