To determine which of the given oxides is the most acidic, we need to analyze the oxides of the elements listed: Nitrogen, Phosphorus, Arsenic, and Antimony. These elements belong to Group 15 of the periodic table, and their oxides are generally classified based on their acidic or basic nature.
### Step-by-Step Solution:
1. **Identify the Oxides**:
- Nitrogen forms N₂O₅ (dinitrogen pentoxide).
- Phosphorus forms P₂O₅ (diphosphorus pentoxide).
- Arsenic forms As₂O₅ (diarsenic pentoxide).
- Antimony forms Sb₂O₅ (diantimony pentoxide).
2. **Understand Acidic Nature**:
- Oxides can be classified as acidic, basic, or amphoteric. Generally, non-metal oxides tend to be acidic, while metal oxides are usually basic.
- Among the non-metal oxides, the acidity tends to increase with the covalent character of the oxide.
3. **Covalent vs. Ionic Character**:
- The covalent character of an oxide increases as the size of the cation decreases and the size of the anion increases.
- In this case, since all the anions (O²⁻) are the same, we focus on the cations (N, P, As, Sb).
4. **Trends in Group 15**:
- As we move down the group from Nitrogen to Antimony, the size of the cation increases.
- A smaller cation has a higher polarizing power, which leads to a more covalent character in the oxide.
5. **Cation Size and Covalent Character**:
- Nitrogen (smallest cation) → most covalent character → most acidic oxide (N₂O₅).
- Antimony (largest cation) → least covalent character → least acidic oxide (Sb₂O₅).
6. **Conclusion**:
- Among the oxides N₂O₅, P₂O₅, As₂O₅, and Sb₂O₅, N₂O₅ has the highest covalent character and is therefore the most acidic oxide.
### Final Answer:
The most acidic oxide among the given options is **N₂O₅** (dinitrogen pentoxide).
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