Intermolecular hydrogen bonding is not present in `:`

Options

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

Answer

To determine which molecule does not exhibit intermolecular hydrogen bonding, we will analyze each of the four given options step by step.

### Step 1: Understand Intermolecular Hydrogen Bonding
Intermolecular hydrogen bonding occurs when a hydrogen atom covalently bonded to a highly electronegative atom (like oxygen, nitrogen, or fluorine) interacts with a lone pair of electrons on another electronegative atom in a neighboring molecule.

### Step 2: Analyze Each Option

**Option 1: Acetic Acid (CH₃COOH)**
- Acetic acid can form dimers due to hydrogen bonding between the hydroxyl group (–OH) of one molecule and the carbonyl oxygen (C=O) of another.
- **Conclusion**: Acetic acid exhibits intermolecular hydrogen bonding.

**Option 2: Ethanol (C₂H₅OH)**
- Ethanol has a hydroxyl group (–OH) that can form hydrogen bonds with other ethanol molecules.
- **Conclusion**: Ethanol exhibits intermolecular hydrogen bonding.

**Option 3: Ether (C₂H₅OC₂H₅)**
- Ethers contain an oxygen atom bonded to two alkyl groups. However, there are no hydrogen atoms directly bonded to the oxygen atom.
- **Conclusion**: Ethers do not exhibit intermolecular hydrogen bonding because there are no hydrogen atoms available to participate in hydrogen bonding.

**Option 4: Ethylamine (C₂H₅NH₂)**
- Ethylamine has a nitrogen atom with a lone pair of electrons and hydrogen atoms attached to it. This allows for hydrogen bonding with other ethylamine molecules.
- **Conclusion**: Ethylamine exhibits intermolecular hydrogen bonding.

### Final Conclusion
Among the four options, the molecule that does not exhibit intermolecular hydrogen bonding is **Option 3: Ether (C₂H₅OC₂H₅)**.

### Summary of the Answer
The correct answer is **Option 3: Ether**.

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