Hydrogen bonding is maximum in

Options

A. `C_6H_5OH`
B. `C_6H_5COOH`
C. `CH_3CH_2OH`
D. `CH_3COCH_3`.

Answer

To determine where hydrogen bonding is maximum among the given compounds, we need to analyze each compound based on the presence of hydrogen atoms bonded to highly electronegative atoms (like oxygen) and the ability of these hydrogen atoms to interact with other electronegative atoms.

### Step-by-Step Solution:

1. **Understanding Hydrogen Bonding**:
- Hydrogen bonding occurs between a hydrogen atom covalently bonded to a highly electronegative atom (like O, N, or F) and another electronegative atom.

2. **Analyzing the Compounds**:
- **Compound 1: Phenol (C6H5OH)**:
- In phenol, the hydroxyl (OH) group has a hydrogen atom attached to oxygen. This hydrogen can form hydrogen bonds with the oxygen of another phenol molecule.
- **Hydrogen bonding possibilities**: 1 (between two phenol molecules).

- **Compound 2: Benzoic Acid (C6H5COOH)**:
- Benzoic acid has a carboxylic acid group (COOH). The hydrogen in the hydroxyl part can form hydrogen bonds with the oxygen of another benzoic acid molecule.
- **Hydrogen bonding possibilities**: 2 (one from the hydroxyl oxygen to the hydrogen of another molecule and one from the carbonyl oxygen to the hydroxyl hydrogen).

- **Compound 3: Ethanol (CH3CH2OH)**:
- Ethanol has an OH group, which can form hydrogen bonds with other ethanol molecules.
- **Hydrogen bonding possibilities**: 1 (between two ethanol molecules).

- **Compound 4: Acetone (CH3COCH3)**:
- Acetone has a carbonyl group (C=O), but the hydrogen atoms are bonded to carbon, which is not highly electronegative. Therefore, acetone cannot form hydrogen bonds.
- **Hydrogen bonding possibilities**: 0.

3. **Comparing the Hydrogen Bonding**:
- From the analysis:
- Phenol: 1 hydrogen bond
- Benzoic Acid: 2 hydrogen bonds
- Ethanol: 1 hydrogen bond
- Acetone: 0 hydrogen bonds

4. **Conclusion**:
- The compound with the maximum hydrogen bonding is **Benzoic Acid (C6H5COOH)**, which can form two hydrogen bonds.

### Final Answer:
Benzoic Acid has the maximum hydrogen bonding.

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