Maximum extent of hydrogen bonding is observed in

Options

A. `C_(6) H_(5)OH`
B. `C_(6)H_(5)COOH`
C. `CH_(3)CH_(2)OH`
D. `CH_(3)COCH_(3)`

Answer

To determine the maximum extent of hydrogen bonding, we need to analyze the given compounds and their ability to form hydrogen bonds based on their molecular structure and the electronegativity of the atoms involved.

### Step 1: Identify the Compounds
The compounds mentioned are:
1. C6H5OH (Phenol)
2. C6H5COH (Benzaldehyde)
3. CH3CH2OH (Ethanol)
4. CH3C(=O)OCH3 (Methyl acetate)

### Step 2: Understand Hydrogen Bonding
Hydrogen bonding occurs when hydrogen is covalently bonded to a highly electronegative atom (like O, N, or F). The electronegative atom pulls electron density away from hydrogen, making it partially positive and capable of forming a bond with a lone pair of electrons from another electronegative atom.

### Step 3: Analyze Each Compound
1. **C6H5OH (Phenol)**: Contains an -OH group. The oxygen is highly electronegative, allowing for hydrogen bonding with other phenol molecules or water.

2. **C6H5COH (Benzaldehyde)**: Contains an -CHO group. While it can participate in hydrogen bonding, the hydrogen is bonded to carbon, which is less electronegative than oxygen, resulting in weaker hydrogen bonding.

3. **CH3CH2OH (Ethanol)**: Also contains an -OH group. Similar to phenol, it can form hydrogen bonds effectively due to the electronegative oxygen.

4. **CH3C(=O)OCH3 (Methyl acetate)**: Contains an ester functional group. It can participate in hydrogen bonding, but the presence of the carbonyl group (C=O) does not enhance hydrogen bonding as effectively as an -OH group.

### Step 4: Compare the Extent of Hydrogen Bonding
- **Phenol** and **Ethanol** both have -OH groups, which are capable of strong hydrogen bonding.
- **Benzaldehyde** has weaker hydrogen bonding due to the hydrogen being attached to carbon.
- **Methyl acetate** can participate in hydrogen bonding but is less effective than the alcohols.

### Conclusion
Among the given compounds, **C6H5OH (Phenol)** and **CH3CH2OH (Ethanol)** exhibit strong hydrogen bonding due to the presence of the -OH group. However, phenol can form more extensive hydrogen bonding networks due to its ability to form stable dimers through hydrogen bonds. Therefore, the maximum extent of hydrogen bonding is observed in **C6H5OH (Phenol)**.

### Final Answer
**Maximum extent of hydrogen bonding is observed in C6H5OH (Phenol).**

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