The conjugate acid of `S_(2)O_(8)^(-2)`

Options

A. `H_(2)S_(2)O_(8)`
B. `H_(2)S_(4)`
C. `HSO_(4)^(-)`
D. `H_(2)S_(2)O_(8)^(-)`

Answer

To find the conjugate acid of \( S_2O_8^{2-} \), we need to understand the concept of conjugate acids and bases. A conjugate acid is formed when a base accepts a proton (H⁺).

### Step-by-Step Solution:

1. **Identify the Base**: In this case, the base is \( S_2O_8^{2-} \).

2. **Proton Acceptance**: To find the conjugate acid, we need to add a proton (H⁺) to the base.

\[ S_2O_8^{2-} + H^+ \rightarrow ? \]

3. **Calculate the Charge**: When we add a proton to \( S_2O_8^{2-} \), the charge of the species will increase by 1.

\[ \text{Charge of } S_2O_8^{2-} = -2 \quad \text{(base)} \]
\[ \text{Charge after adding } H^+ = -2 + 1 = -1 \]

4. **Formulate the Conjugate Acid**: The resulting species after adding the proton is \( H S_2O_8^{-} \).

5. **Conclusion**: Therefore, the conjugate acid of \( S_2O_8^{2-} \) is \( H S_2O_8^{-} \).

### Final Answer:
The conjugate acid of \( S_2O_8^{2-} \) is \( H S_2O_8^{-} \).

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