Which of the following oxides is the most acidic?

Options

A. `CO_2`
B. `AI_2 O_3`
C. `P_2 O_5`
D. `SO_3`

Answer

To determine which of the given oxides is the most acidic, we need to analyze the oxidation states of the central atoms in each oxide and understand how these oxidation states relate to acidity.

### Step-by-Step Solution:

1. **Identify the Oxides**: Let's assume the oxides in question are CO2, Al2O3, P2O5, and SO3.

2. **Calculate the Oxidation States**:
- For **CO2**:
- Let the oxidation state of carbon be \(X\).
- The equation is \(X + 2(-2) = 0\) (since oxygen has a -2 oxidation state).
- Solving gives \(X - 4 = 0\) → \(X = +4\).

- For **Al2O3**:
- Let the oxidation state of aluminum be \(X\).
- The equation is \(2X + 3(-2) = 0\).
- Solving gives \(2X - 6 = 0\) → \(2X = 6\) → \(X = +3\).

- For **P2O5**:
- Let the oxidation state of phosphorus be \(X\).
- The equation is \(2X + 5(-2) = 0\).
- Solving gives \(2X - 10 = 0\) → \(2X = 10\) → \(X = +5\).

- For **SO3**:
- Let the oxidation state of sulfur be \(X\).
- The equation is \(X + 3(-2) = 0\).
- Solving gives \(X - 6 = 0\) → \(X = +6\).

3. **Determine Acidity Based on Oxidation States**:
- Acidity of oxides generally increases with the oxidation state of the central atom. Higher oxidation states indicate a greater ability to accept electrons and form acidic solutions.
- From our calculations:
- CO2 has +4 oxidation state.
- Al2O3 has +3 oxidation state.
- P2O5 has +5 oxidation state.
- SO3 has +6 oxidation state.

4. **Conclusion**:
- Among the oxides analyzed, SO3 has the highest oxidation state (+6), indicating it is the most acidic oxide.

### Final Answer:
**SO3 is the most acidic oxide among the given options.**