Which of the following species is/are not liberating oxygen gas on reaction with water at `25^(@)C`?

Options

A. `Na_(2)O_(2)`
B. `Cl_(2)`
C. `P_(4)`
D. `KO_(2)`

Explanation

To determine which species do not liberate oxygen gas when reacting with water at 25°C, we will analyze each option given in the question.

### Step-by-Step Solution:

1. **Analyze Na2O2 (Sodium Peroxide)**:
- Reaction: \( \text{Na}_2\text{O}_2 + \text{H}_2\text{O} \rightarrow \text{NaOH} + \text{O}_2 \)
- Conclusion: This reaction produces oxygen gas (O2). Therefore, Na2O2 **does liberate oxygen gas**.

2. **Analyze Cl2 (Chlorine)**:
- Reaction: \( \text{Cl}_2 + \text{H}_2\text{O} \rightarrow \text{HCl} + \text{HOCl} \)
- Conclusion: This reaction does not produce oxygen gas. Therefore, Cl2 **does not liberate oxygen gas**.

3. **Analyze P4 (White Phosphorus)**:
- Reaction: \( \text{P}_4 + \text{H}_2\text{O} \rightarrow \text{No Reaction} \)
- Conclusion: There is no reaction between P4 and water at 25°C, meaning no oxygen gas is produced. Therefore, P4 **does not liberate oxygen gas**.

4. **Analyze KO2 (Potassium Superoxide)**:
- Reaction: \( \text{KO}_2 + \text{H}_2\text{O} \rightarrow \text{KOH} + \text{O} \)
- Conclusion: This reaction produces oxygen gas (O). Therefore, KO2 **does liberate oxygen gas**.

### Final Conclusion:
The species that do not liberate oxygen gas when reacting with water at 25°C are:
- Cl2 (Chlorine)
- P4 (White Phosphorus)