The formation of `O_(3)` from `O_(2)` is

Options

A. exothermic and reversible
B. endothermic and irreversible
C. endothermic and reversible
D. exothermic and spontaneous

Answer

To determine the nature of the formation of ozone (O₃) from oxygen (O₂), we can analyze the process step by step:

### Step 1: Understanding the Reaction
The reaction we are considering is:
\[ 3O_2 \rightarrow 2O_3 \]
This reaction involves the conversion of molecular oxygen (O₂) into ozone (O₃).

### Step 2: Stability of Reactants and Products
- O₂ is a more stable molecule compared to O₃.
- Stability is associated with lower energy states. Since O₂ is more stable, it has lower energy than O₃.

### Step 3: Energy Requirement
To convert O₂ into O₃, energy must be supplied because we are moving from a more stable (lower energy) state to a less stable (higher energy) state. This indicates that the process requires energy input.

### Step 4: Classifying the Reaction
Since energy is absorbed to form O₃ from O₂, this reaction is classified as **endothermic**.

### Step 5: Reversibility of the Reaction
The formation of ozone is a reversible process. Ozone (O₃) can decompose back into oxygen (O₂), especially since O₃ is less stable and has a higher energy state compared to O₂. Therefore, the reaction can proceed in both directions.

### Conclusion
Based on the analysis:
- The formation of O₃ from O₂ is **endothermic** because it requires energy input.
- The reaction is also **reversible** since O₃ can revert back to O₂.

Thus, the correct answer is: **Endothermic and Reversible**.

### Final Answer
The formation of O₃ from O₂ is an **endothermic and reversible** process.

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