The redox reaction among the following is

Options

A. `2NaOH+Cl_(2)rarr NaCl +NaOCl +H_(2)O`
B. Formation of ozone from atmospheric oxygen in the presence of sunlight
C. reaction of `[Co(H_(2)O)_(6)]Cl_(3)` with `AgNO_(3)`
D. reaction of `H_(2)SO_(4)` with `NaOH`

Answer

To determine which of the given reactions is a redox reaction, we need to analyze the oxidation states of the elements involved in each reaction. A redox reaction involves both oxidation (increase in oxidation state) and reduction (decrease in oxidation state) occurring simultaneously.

**Step-by-Step Solution:**

1. **Identify the Reactions**: We have four reactions to analyze for redox behavior.

2. **Analyze Reaction 1**:
- **Reaction**: 2 NaOH + Cl2 → NaCl + NaOCl + H2O
- **Oxidation States**:
- Na in NaOH: +1
- O in NaOH: -2
- Cl in Cl2: 0 (elemental state)
- Na in NaCl: +1
- Cl in NaOCl: +1
- O in NaOCl: -2
- H in H2O: +1
- O in H2O: -2
- **Change in Oxidation States**:
- Cl changes from 0 (in Cl2) to -1 (in NaCl) and +1 (in NaOCl).
- **Conclusion**: Since there is a change in oxidation states (Cl is reduced and oxidized), this is a redox reaction.

3. **Analyze Reaction 2**:
- **Reaction**: 3 O2 → O3 (formation of ozone)
- **Oxidation States**:
- O in O2: 0
- O in O3: 0
- **Change in Oxidation States**: No change in oxidation states.
- **Conclusion**: This is not a redox reaction.

4. **Analyze Reaction 3**:
- **Reaction**: [Co(H2O)6]Cl3 + 3 AgNO3 → [Co(H2O)6](NO3)3 + 3 AgCl
- **Oxidation States**:
- Co in [Co(H2O)6]Cl3: +3
- H2O: 0
- Cl: -1
- Ag in AgNO3: +1
- N in NO3: +5
- O in NO3: -2
- **Change in Oxidation States**: No change in oxidation states.
- **Conclusion**: This is not a redox reaction.

5. **Analyze Reaction 4**:
- **Reaction**: H2SO4 + 2 NaOH → Na2SO4 + 2 H2O
- **Oxidation States**:
- H in H2SO4: +1
- S in H2SO4: +6
- O in H2SO4: -2
- Na in NaOH: +1
- O in NaOH: -1
- **Change in Oxidation States**: No change in oxidation states.
- **Conclusion**: This is not a redox reaction.

6. **Final Conclusion**: The only redox reaction among the given options is the first reaction (2 NaOH + Cl2 → NaCl + NaOCl + H2O).