Which of the following is most acidic ?

Options

A. `Cl_(2)O_(7)`
B. `SO_(3)`
C. `P_(2)O_(5)`
D. `SiO_(2)`

Answer

To determine which of the given acids is the most acidic, we need to analyze the oxidation states of the central atoms in each acid. The acidity of an acid is generally related to the oxidation state of the central atom; higher oxidation states typically correspond to stronger acids.

### Step-by-Step Solution:

1. **Identify the Acids**: The acids given are Cl2O7, SO3, P2O5, and SiO2.

2. **Calculate the Oxidation State of Cl in Cl2O7**:
- The formula for Cl2O7 can be represented as:
\[ 2x + (-2) \times 7 = 0 \]
- Solving for x:
\[ 2x - 14 = 0 \implies 2x = 14 \implies x = +7 \]
- Therefore, the oxidation state of Cl in Cl2O7 is +7.

3. **Calculate the Oxidation State of S in SO3**:
- The formula for SO3 can be represented as:
\[ x + (-2) \times 3 = 0 \]
- Solving for x:
\[ x - 6 = 0 \implies x = +6 \]
- Therefore, the oxidation state of S in SO3 is +6.

4. **Calculate the Oxidation State of P in P2O5**:
- The formula for P2O5 can be represented as:
\[ 2x + (-2) \times 5 = 0 \]
- Solving for x:
\[ 2x - 10 = 0 \implies 2x = 10 \implies x = +5 \]
- Therefore, the oxidation state of P in P2O5 is +5.

5. **Calculate the Oxidation State of Si in SiO2**:
- The formula for SiO2 can be represented as:
\[ x + (-2) \times 2 = 0 \]
- Solving for x:
\[ x - 4 = 0 \implies x = +4 \]
- Therefore, the oxidation state of Si in SiO2 is +4.

6. **Compare the Oxidation States**:
- Cl in Cl2O7: +7
- S in SO3: +6
- P in P2O5: +5
- Si in SiO2: +4

7. **Determine the Most Acidic Compound**:
- Since Cl2O7 has the highest oxidation state (+7), it is the most acidic among the given acids.

### Conclusion:
The most acidic compound among Cl2O7, SO3, P2O5, and SiO2 is **Cl2O7**.

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