Which of the following compounds can form H-bonding with each other ?

Options

A. `CH_(3)CO OH and H_(2)O`
B. Phenol and `CH_(4)`
C. `CHF_(3)` and acetone
D. `PH_(3)` and HF

Explanation

To determine which of the given compounds can form hydrogen bonding with each other, we need to analyze the presence of hydrogen bond donors and acceptors in each option. Hydrogen bonding typically occurs when a hydrogen atom is bonded to a highly electronegative atom (like N, O, or F) and is attracted to a lone pair of electrons on another electronegative atom.

### Step-by-Step Solution:

1. **Identify the Compounds**: We have the following compounds to analyze:
- Option A: CH3COOH (acetic acid) and H2O (water)
- Option B: Phenol and CH4 (methane)
- Option C: CHF3 (trifluoromethane) and acetone
- Option D: PH3 (phosphine) and HF (hydrogen fluoride)

2. **Analyze Option A (CH3COOH and H2O)**:
- CH3COOH has a hydroxyl group (-OH) which can act as a hydrogen bond donor. The oxygen atom has a lone pair.
- H2O also has two hydrogen atoms that can act as hydrogen bond donors and two lone pairs on the oxygen atom.
- Since both molecules have polar characteristics and the presence of lone pairs, they can form hydrogen bonds with each other.

3. **Analyze Option B (Phenol and CH4)**:
- Phenol has a hydroxyl group (-OH) and can act as a hydrogen bond donor.
- CH4 is a non-polar molecule and does not have any electronegative atoms or lone pairs. Therefore, it cannot participate in hydrogen bonding.
- This option does not form hydrogen bonds.

4. **Analyze Option C (CHF3 and Acetone)**:
- CHF3 has a polar C-F bond, but it does not have a hydrogen atom bonded to an electronegative atom that can act as a hydrogen bond donor.
- Acetone (CH3COCH3) has a carbonyl group (C=O) which can act as a hydrogen bond acceptor but lacks hydrogen bond donors.
- Therefore, this option does not form hydrogen bonds.

5. **Analyze Option D (PH3 and HF)**:
- PH3 has a hydrogen atom but is not very electronegative and does not form strong hydrogen bonds.
- HF has a very electronegative fluorine atom and can act as a hydrogen bond donor.
- However, PH3 does not effectively participate in hydrogen bonding due to its weak hydrogen bond capability.
- Therefore, this option does not form hydrogen bonds.

6. **Conclusion**: The only pair of compounds that can form hydrogen bonding with each other is Option A: CH3COOH and H2O.

### Final Answer:
The compounds that can form hydrogen bonding with each other are **Option A: CH3COOH and H2O**.

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