Which one of the following reactions does not occur ?

Options

A. `BaO+O_(3)rarr BaO_(2)+O_(2)`
B. `PbS+4O_(3)rarr PbSO_(4)+4O_(2)`
C. `H_(2)O_(2)+O_(3)rarr H_(2)O+2O_(2)`
D. `2Hg+O_(3)rarr Hg_(2)O+O_(2)`

Answer

To determine which of the given reactions does not occur, we will analyze each reaction step by step.

### Step 1: Analyze the first reaction
**Reaction:** \( \text{BaO} + \text{O}_3 \rightarrow \text{BaO}_2 + \text{O}_2 \)

- **Analysis:** Barium oxide (BaO) is a basic oxide. Ozone (O3) is a strong oxidizing agent. Typically, BaO can react with ozone, but in this case, the formation of BaO2 (barium peroxide) and oxygen (O2) from BaO and O3 is not a favorable reaction. The reaction does not occur as written.

### Step 2: Analyze the second reaction
**Reaction:** \( \text{H}_2 + \text{H}_2\text{O}_2 + \text{O}_3 \rightarrow \text{H}_2\text{O} + 2\text{O}_2 \)

- **Analysis:** In this reaction, hydrogen (H2) reacts with hydrogen peroxide (H2O2) and ozone (O3). Ozone can act as a reducing agent in this context, and the reaction can produce water (H2O) and oxygen (O2). This reaction is possible.

### Step 3: Analyze the third reaction
**Reaction:** \( \text{PbS} + 4\text{O}_3 \rightarrow \text{PbSO}_4 + 4\text{O}_2 \)

- **Analysis:** Lead sulfide (PbS) reacts with ozone to form lead sulfate (PbSO4) and oxygen. This reaction is also feasible as ozone can oxidize PbS to PbSO4.

### Step 4: Analyze the fourth reaction
**Reaction:** \( 2\text{Hg} + \text{O}_3 \rightarrow \text{Hg}_2\text{O} + \text{O}_2 \)

- **Analysis:** Mercury (Hg) can react with ozone to form mercuric oxide (Hg2O) and oxygen. This reaction is possible as ozone oxidizes mercury from its elemental state (0) to a +2 oxidation state.

### Conclusion
After analyzing all the reactions, we find that the first reaction \( \text{BaO} + \text{O}_3 \rightarrow \text{BaO}_2 + \text{O}_2 \) does not occur.

### Final Answer
The reaction that does not occur is: **Option 1: \( \text{BaO} + \text{O}_3 \rightarrow \text{BaO}_2 + \text{O}_2 \)**.

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