Among `Al_2O_3, SiO_2, P_2O_3 and SO_2` the correct order of acid strength is

Options

A. `Al_2O_3 lt SiO_2 lt SO_2 lt P_2O_3`
B. `Al_2O_3 lt SiO_2 lt P_2O_3 lt SO_2`
C. `SiO_2 lt SO_2 lt Al_2O_3 lt P_2O_3 `
D. `SO_2 lt P_2O_3 lt SiO_2 lt Al_2O_3 `

Answer

To determine the correct order of acid strength among Al₂O₃, SiO₂, P₂O₃, and SO₂, we will analyze the acidic and basic nature of these oxides based on their position in the periodic table and their chemical properties.

### Step-by-Step Solution:

1. **Identify the Oxides**:
- We have four oxides: Al₂O₃ (aluminum oxide), SiO₂ (silicon dioxide), P₂O₃ (phosphorus trioxide), and SO₂ (sulfur dioxide).

2. **Understand Acid-Base Character**:
- The acid-base character of oxides can be understood based on their position in the periodic table. Generally, as we move from left to right across a period, the basic nature of oxides decreases while the acidic nature increases.

3. **Determine the Acidic Nature**:
- **SO₂**: Sulfur is in the non-metal region and is known to form acidic oxides. SO₂ is a well-known acidic oxide.
- **P₂O₃**: Phosphorus is also a non-metal and forms acidic oxides, though it is less acidic than SO₂.
- **SiO₂**: Silicon is a metalloid and forms a weakly acidic oxide. It is less acidic than both SO₂ and P₂O₃.
- **Al₂O₃**: Aluminum oxide is amphoteric, meaning it can act as both an acid and a base, but it is generally considered to be more basic compared to the other oxides listed.

4. **Rank the Acid Strength**:
- Based on the above analysis, we can rank the oxides in terms of their acid strength:
- **SO₂** > **P₂O₃** > **SiO₂** > **Al₂O₃**

5. **Final Order**:
- Therefore, the correct order of acid strength is:
- SO₂ > P₂O₃ > SiO₂ > Al₂O₃

### Conclusion:
The correct order of acid strength among the given oxides is:
- SO₂ > P₂O₃ > SiO₂ > Al₂O₃