Which of the following hydrogen bonds is the strongest ?

Options

A. `O-H……N`
B. `F-H…..F`
C. `O-H….O`
D. `O-H…..F`

Explanation

To determine which of the given hydrogen bonds is the strongest, we need to analyze the electronegativity differences in each of the compounds listed. The strength of hydrogen bonds is influenced by the electronegativity of the atoms involved, particularly the atom bonded to hydrogen.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- The question provides several compounds with potential hydrogen bonds. Let's denote them as:
- A: H-O (O-H triple bond N)
- B: H-F (F-H-F)
- C: O-H (water, H-O-H)
- D: O-H and F (H-O and H-F)

2. **Determine Electronegativity Values**:
- The electronegativity values for the relevant elements are:
- Hydrogen (H): 2.2
- Oxygen (O): 3.4
- Nitrogen (N): 3.0
- Fluorine (F): 4.0
- Chlorine (Cl): 3.0

3. **Calculate Electronegativity Differences**:
- For each compound, calculate the electronegativity difference between hydrogen and the electronegative atom:
- **Compound A (O-H-N)**:
- O (3.4) - H (2.2) = 1.2
- N (3.0) - H (2.2) = 0.8
- **Compound B (H-F)**:
- F (4.0) - H (2.2) = 1.8
- **Compound C (H-O-H)**:
- O (3.4) - H (2.2) = 1.2
- **Compound D (H-O and H-F)**:
- O (3.4) - H (2.2) = 1.2
- F (4.0) - H (2.2) = 1.8

4. **Compare the Electronegativity Differences**:
- From the calculations, we have:
- Compound A: 1.2 (O-H) and 0.8 (N-H)
- Compound B: 1.8 (H-F)
- Compound C: 1.2 (H-O)
- Compound D: 1.2 (H-O) and 1.8 (H-F)
- The highest electronegativity difference is found in Compound B and Compound D (both have 1.8).

5. **Conclusion**:
- Since Compound B (H-F) has the highest electronegativity difference (1.8), it represents the strongest hydrogen bond among the options provided.

### Final Answer:
The strongest hydrogen bond is in **Compound B (H-F)**.

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