The correct order of the strength of H-bonds is :

Options

A. `H….FgtH….OgtH…..N`
B. `H….NgtH….OgtH….F`
C. `H….OgtH….NgtH….F`
D. `H….FgtH….NgtH….O`

Answer

To determine the correct order of the strength of hydrogen bonds, we can follow these steps:

### Step 1: Understand Hydrogen Bonding
Hydrogen bonding occurs when hydrogen is covalently bonded to a highly electronegative atom (like F, O, or N) and interacts with another electronegative atom. The strength of hydrogen bonds is influenced by the electronegativity of the atoms involved.

**Hint:** Recall that electronegativity is the tendency of an atom to attract electrons. The more electronegative the atom bonded to hydrogen, the stronger the hydrogen bond.

### Step 2: Identify the Atoms Involved
In the question, we are considering hydrogen bonds involving three different atoms: fluorine (F), oxygen (O), and nitrogen (N).

**Hint:** Make a list of the atoms and their electronegativities to compare them.

### Step 3: Compare Electronegativity
The electronegativity values for the relevant atoms are approximately:
- Fluorine (F): 4.0
- Oxygen (O): 3.5
- Nitrogen (N): 3.0

From this, we can see that fluorine is the most electronegative, followed by oxygen, and then nitrogen.

**Hint:** Remember that the greater the difference in electronegativity between hydrogen and the electronegative atom, the stronger the hydrogen bond.

### Step 4: Determine the Strength of Hydrogen Bonds
Based on the electronegativity values, we can predict the strength of the hydrogen bonds:
- HF (Hydrogen Fluoride) will have the strongest hydrogen bond due to fluorine's high electronegativity.
- HO (Water) will have a weaker hydrogen bond than HF but stronger than HN.
- HN (Hydrogen Nitride or Ammonia) will have the weakest hydrogen bond among these three.

**Hint:** Think about how the strength of hydrogen bonds decreases with decreasing electronegativity of the atom bonded to hydrogen.

### Step 5: Write the Order of Strength
Thus, the order of strength of hydrogen bonds from strongest to weakest is:
1. HF (Hydrogen Fluoride)
2. HO (Water)
3. HN (Ammonia)

**Hint:** You can visualize this order as a ranking system based on electronegativity.

### Final Answer
The correct order of the strength of hydrogen bonds is: **HF > HO > HN**.