Which of the following compounds has the least tendency to from H-bonds ? .

Options

A. `HF`
B. `HCI`
C. `H_(2)O`
D. `NH_(3)`

Explanation

To determine which of the compounds HF, HCl, H2O, and NH3 has the least tendency to form hydrogen bonds, we need to analyze the ability of each compound to engage in hydrogen bonding based on the electronegativity and size of the atoms involved.

### Step-by-Step Solution:

1. **Understanding Hydrogen Bonding**:
- Hydrogen bonds are a type of strong intermolecular force that occurs when a hydrogen atom covalently bonded to a highly electronegative atom (like F, O, or N) is attracted to another electronegative atom.
- The strength of hydrogen bonds is influenced by the electronegativity of the atoms involved and the size of the atoms.

2. **Analyzing Each Compound**:
- **HF (Hydrogen Fluoride)**:
- Hydrogen is bonded to fluorine, which is highly electronegative (electronegativity of 4.0). This results in strong hydrogen bonding.
- **HCl (Hydrogen Chloride)**:
- Hydrogen is bonded to chlorine, which is less electronegative than fluorine (electronegativity of 3.0). Therefore, HCl has weaker hydrogen bonding compared to HF.
- **H2O (Water)**:
- In water, hydrogen is bonded to oxygen, which has an electronegativity of 3.5. Water is known for its strong hydrogen bonding due to the presence of two hydrogen atoms bonded to a single oxygen atom.
- **NH3 (Ammonia)**:
- In ammonia, hydrogen is bonded to nitrogen, which has an electronegativity of 3.0. Ammonia also exhibits hydrogen bonding, but it is generally weaker than that in water.

3. **Comparing the Compounds**:
- Based on the electronegativities:
- HF > H2O > NH3 > HCl
- Since HCl has the lowest electronegativity and the largest atomic size among the relevant atoms (compared to F, O, and N), it will have the least tendency to form hydrogen bonds.

4. **Conclusion**:
- Therefore, the compound with the least tendency to form hydrogen bonds is **HCl**.

### Final Answer:
**HCl** has the least tendency to form hydrogen bonds.