Among `NH_(3),H_(2)O`, and `HF`, which would you expect to have highest magnitude of hydrogen bonding and why?

Options

A. HF due to maximum polarity.
B. `H_(2)O` due to lone pairs of electrons.
C. `NH_(3)` due to small size of nitrogen.
D. `H_(2)S` due to higher electron affinity of sulphur.

Explanation

To determine which compound among NH₃ (ammonia), H₂O (water), and HF (hydrogen fluoride) has the highest magnitude of hydrogen bonding, we can analyze the electronegativity and molecular structure of each compound.

### Step-by-Step Solution:

1. **Understanding Hydrogen Bonding**:
- Hydrogen bonding occurs when hydrogen is bonded to a highly electronegative atom (like F, O, or N) and is attracted to another electronegative atom. The strength of hydrogen bonding is influenced by the polarity of the bond.

2. **Electronegativity of Atoms**:
- The electronegativities of the relevant atoms are as follows:
- Fluorine (F) - 4.0
- Oxygen (O) - 3.5
- Nitrogen (N) - 3.0
- Since fluorine is the most electronegative, it will create the most polar bond when bonded to hydrogen.

3. **Analyzing Each Compound**:
- **HF (Hydrogen Fluoride)**:
- The bond between H and F is highly polar due to the high electronegativity of F. This results in a significant partial positive charge on H and a significant partial negative charge on F, leading to strong hydrogen bonding.
- **H₂O (Water)**:
- Water has two hydrogen atoms bonded to one oxygen atom. The O-H bond is also polar, but the overall hydrogen bonding strength is less than that of HF due to the lower electronegativity of O compared to F.
- **NH₃ (Ammonia)**:
- Ammonia has one nitrogen atom bonded to three hydrogen atoms. While N is electronegative, it is less so than F, resulting in weaker hydrogen bonds compared to HF and H₂O.

4. **Conclusion**:
- Among NH₃, H₂O, and HF, HF has the highest magnitude of hydrogen bonding due to the high polarity of the H-F bond resulting from the high electronegativity of fluorine.

### Final Answer:
**HF (Hydrogen Fluoride) has the highest magnitude of hydrogen bonding due to its maximum polarity resulting from the high electronegativity of fluorine.**