. Which of the following will have the lowest pH?

Options

A. NaCIO
B. `NaCIO_(2)`
C. `NaCIO_(3)`
D. `NaCIO_(4)`

Explanation

To determine which of the given compounds has the lowest pH, we need to analyze their acidic strength based on the oxidation states of the central atom, which in this case is chlorine (Cl). The higher the oxidation state of chlorine, the stronger the acid, and consequently, the lower the pH.

### Step-by-Step Solution:

1. **Identify the Compounds**: We need to evaluate the acidic strength of the following compounds: ClO3, NaClO4, and NaClO2.

2. **Calculate the Oxidation State of Chlorine in Each Compound**:
- **For NaClO4**:
- Sodium (Na) has an oxidation state of +1.
- Let the oxidation state of Cl be x.
- The equation becomes:
\[ +1 + x + (-2) \times 4 = 0 \implies 1 + x - 8 = 0 \implies x = +7 \]
- **For NaClO3**:
- Sodium (Na) has an oxidation state of +1.
- Let the oxidation state of Cl be x.
- The equation becomes:
\[ +1 + x + (-2) \times 3 = 0 \implies 1 + x - 6 = 0 \implies x = +5 \]
- **For NaClO2**:
- Sodium (Na) has an oxidation state of +1.
- Let the oxidation state of Cl be x.
- The equation becomes:
\[ +1 + x + (-2) \times 2 = 0 \implies 1 + x - 4 = 0 \implies x = +3 \]

3. **Summarize the Oxidation States**:
- NaClO4: Cl = +7
- NaClO3: Cl = +5
- NaClO2: Cl = +3

4. **Determine the Acidic Strength**:
- The acidic strength is directly proportional to the oxidation state of the central atom (Cl in this case). Therefore:
- NaClO4 (Cl = +7) has the highest acidic strength.
- NaClO3 (Cl = +5) has moderate acidic strength.
- NaClO2 (Cl = +3) has the lowest acidic strength.

5. **Conclusion**:
- Since NaClO4 has the highest oxidation state and thus the highest acidic strength, it will have the lowest pH among the compounds listed.

### Final Answer:
The compound with the lowest pH is **NaClO4**.

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