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 the oxides `Al_2O_3`, `SiO_2`, `P_2O_3`, and `SO_2`, we can analyze the non-metallic character of the elements involved and how it relates to the acidity of their oxides. Here’s a step-by-step solution:

### Step 1: Identify the Nature of the Oxides
- **Aluminum Oxide (Al₂O₃)**: This oxide is amphoteric, meaning it can act as both an acid and a base.
- **Silicon Dioxide (SiO₂)**: This oxide is generally considered acidic.
- **Phosphorus Trioxide (P₂O₃)**: This oxide is also acidic.
- **Sulfur Dioxide (SO₂)**: This oxide is acidic as well.

### Step 2: Determine the Non-metallic Character
- The non-metallic character increases as we move from left to right across a period in the periodic table.
- In our case, we are looking at elements from groups 13 (Al), 14 (Si), 15 (P), and 16 (S).

### Step 3: Order of Non-metallic Character
- **Sulfur (S)** > **Phosphorus (P)** > **Silicon (Si)** > **Aluminum (Al)**
- Therefore, the order of non-metallic character is:
- SO₂ > P₂O₃ > SiO₂ > Al₂O₃

### Step 4: Relate Non-metallic Character to Acid Strength
- The more non-metallic an element is, the stronger the acid its oxide will be.
- Thus, the order of acidic strength based on non-metallic character is:
- SO₂ > P₂O₃ > SiO₂ > Al₂O₃

### Step 5: Final Order of Acid Strength
- The correct order of acid strength is:
- **SO₂ > P₂O₃ > SiO₂ > Al₂O₃**

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