Which of the following is not a disproportionation reaction ?

Options

A. `P_(4)(s)+3OH^(-)(aq)+3H_(2)O(l)toPH_(3)(g)+3H_(2)PO_(2)^(-)(aq)`
B. `2F_(2)(g)+2OH^(-)(aq)to2F^(-)(aq)+OF_(2)(g)+H_(2)O(l)`
C. `Cl_(2)(g)+2OH^(-)(aq)toClO^(-)(aq)+Cl^(-)(aq)+H_(2)O(l)`
D. `2H_(2)O_(2)(aq)to2H_(2)O(l)+O_(2)(g)`

Answer

To determine which of the given reactions is not a disproportionation reaction, we first need to understand what a disproportionation reaction is. A disproportionation reaction occurs when a single species is simultaneously oxidized and reduced, resulting in two different products.

### Step-by-Step Solution:

1. **Identify the Reactions**: We are provided with four reactions. We need to analyze each reaction to see if the same species undergoes both oxidation and reduction.

2. **Define Oxidation and Reduction**:
- **Oxidation**: Loss of electrons (increase in oxidation state).
- **Reduction**: Gain of electrons (decrease in oxidation state).

3. **Analyze Each Reaction**:
- **Reaction 1**:
- **P4**: Oxidation state = 0.
- **Products**: OH⁻, H₃PO₃, H₂P₂O₂.
- **Phosphorus**: Changes from 0 to +1 (oxidation) and -3 (reduction).
- **Conclusion**: This is a disproportionation reaction since phosphorus is both oxidized and reduced.

- **Reaction 2**:
- **Fluorine (F₂)**: Oxidation state = 0.
- **Products**: F⁻, H₂O.
- **Fluorine**: Changes from 0 to -1 (reduction) in both cases.
- **Conclusion**: This is NOT a disproportionation reaction because fluorine does not undergo both oxidation and reduction.

- **Reaction 3**:
- **Cl₂**: Oxidation state = 0.
- **Products**: Cl⁻, Cl⁺, H₂O.
- **Chlorine**: Changes from 0 to +1 (oxidation) and -1 (reduction).
- **Conclusion**: This is a disproportionation reaction since chlorine is both oxidized and reduced.

- **Reaction 4**:
- **H₂O₂**: Oxidation state of oxygen = -1.
- **Products**: H₂O, O₂.
- **Oxygen**: Changes from -1 to -2 (reduction) and -1 to 0 (oxidation).
- **Conclusion**: This is a disproportionation reaction since oxygen is both oxidized and reduced.

4. **Final Conclusion**: The only reaction that is not a disproportionation reaction is **Reaction 2**.

### Answer:
**The reaction that is not a disproportionation reaction is Reaction 2.**

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