The correct order of boiling point is :

Options

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

Answer

To determine the correct order of boiling points for the compounds H2O2 (hydrogen peroxide), H2O (water), HF (hydrofluoric acid), and NH3 (ammonia), we need to analyze the hydrogen bonding capabilities of each compound.

### Step-by-Step Solution:

1. **Identify the Compounds and Their Hydrogen Bonding:**
- The compounds in question are H2O2, H2O, HF, and NH3.
- All these compounds involve hydrogen bonding due to the presence of hydrogen atoms bonded to highly electronegative atoms (O, N, F).

2. **Analyze Hydrogen Bonding in Each Compound:**
- **H2O2 (Hydrogen Peroxide):**
- H2O2 can form hydrogen bonds, and it has a unique structure that allows for significant hydrogen bonding.
- **H2O (Water):**
- Water is known for its strong hydrogen bonding capabilities, where each water molecule can form up to 4 hydrogen bonds.
- **HF (Hydrofluoric Acid):**
- HF can form hydrogen bonds, but each HF molecule can form only 2 hydrogen bonds due to its linear structure.
- **NH3 (Ammonia):**
- Ammonia can also form hydrogen bonds, but it can form fewer than water.

3. **Compare Boiling Points Based on Hydrogen Bonding:**
- **H2O2 vs. H2O:**
- H2O2 has stronger hydrogen bonding than H2O, so H2O2 has a higher boiling point than H2O.
- **H2O vs. HF:**
- Water can form more hydrogen bonds (4) compared to HF (2), so H2O has a higher boiling point than HF.
- **HF vs. NH3:**
- HF has stronger hydrogen bonding due to the greater electronegativity of fluorine compared to nitrogen in NH3. Thus, HF has a higher boiling point than NH3.

4. **Establish the Final Order of Boiling Points:**
- Based on the analysis, the order of boiling points from highest to lowest is:
- H2O2 > H2O > HF > NH3

### Final Answer:
The correct order of boiling points is:
**H2O2 > H2O > HF > NH3**