Which of the following oxides is most acidic ?

Options

A. `As_(2) O_(5)`
B. `P_(2) O_(5)`
C. `N_(2) O_(5)`
D. `Sb_(2) O_(5)`

Answer

To determine which of the given oxides is the most acidic, we will analyze the oxides based on their chemical properties and the trends in acidity among the group 15 elements.

### Step-by-Step Solution:

1. **Identify the Oxides**: The oxides given are:
- As₂O₅ (Arsenic pentoxide)
- P₂O₅ (Phosphorus pentoxide)
- N₂O₅ (Nitrogen pentoxide)
- Sb₂O₅ (Antimony pentoxide)

2. **Understand the Group**: All these oxides are derived from elements in group 15 of the periodic table:
- Nitrogen (N)
- Phosphorus (P)
- Arsenic (As)
- Antimony (Sb)

3. **Acidity Trend in Group 15**: The acidity of oxides generally decreases as we move down the group. This is due to the following reasons:
- **Electronegativity**: As we move down the group, electronegativity decreases. Higher electronegativity in the elements leads to stronger acidic properties in their oxides.
- **Metallic Character**: The metallic character increases down the group, which tends to enhance basic properties and reduce acidic properties.

4. **Compare the Oxides**:
- **N₂O₅**: Nitrogen is at the top of the group, and its oxide is known to be highly acidic.
- **P₂O₅**: Phosphorus is lower than nitrogen, and its oxide is less acidic than N₂O₅.
- **As₂O₅**: Arsenic is lower than phosphorus, making As₂O₅ even less acidic.
- **Sb₂O₅**: Antimony is at the bottom of the group, and its oxide is the least acidic among the four.

5. **Conclusion**: Based on the trend that acidity decreases from nitrogen to antimony, we conclude that N₂O₅ is the most acidic oxide among the given options.

### Final Answer:
The most acidic oxide among the given options is **N₂O₅**.

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