Which of the following compounds has the least tendency to form hydrogen bonds between molecules?

Options

A. `NH_3`
B. `NH_2 OH`
C. HF
D. `CH_3F`

Explanation

To determine which compound has the least tendency to form hydrogen bonds between molecules, we will analyze the given options: ammonia (NH3), hydroxylamine (NH2OH), hydrogen fluoride (HF), and methyl fluoride (CH3F).

### Step 1: Understanding Hydrogen Bonding
Hydrogen bonding occurs when hydrogen is covalently bonded to a highly electronegative atom (such as nitrogen, oxygen, or fluorine) and can interact with another electronegative atom. The ability to form hydrogen bonds depends on the presence of hydrogen attached to these electronegative atoms.

### Step 2: Analyzing Each Compound
1. **Ammonia (NH3)**:
- NH3 has hydrogen atoms bonded to nitrogen, which is electronegative. Therefore, NH3 can form hydrogen bonds with other NH3 molecules.

2. **Hydroxylamine (NH2OH)**:
- NH2OH contains hydrogen atoms bonded to both nitrogen and oxygen. The presence of the -OH group allows for hydrogen bonding, making it capable of forming hydrogen bonds.

3. **Hydrogen Fluoride (HF)**:
- HF has hydrogen bonded directly to fluorine, which is highly electronegative. HF can form strong hydrogen bonds with other HF molecules.

4. **Methyl Fluoride (CH3F)**:
- In CH3F, the hydrogen atoms are bonded to carbon, while fluorine is bonded to carbon as well. Since the hydrogen is not directly bonded to fluorine, CH3F does not have the ability to form hydrogen bonds between its molecules.

### Step 3: Conclusion
Among the compounds analyzed, **methyl fluoride (CH3F)** has the least tendency to form hydrogen bonds because the hydrogen atoms are not directly bonded to an electronegative atom (like nitrogen, oxygen, or fluorine). Therefore, the correct answer is **option D: CH3F**.

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