Which of the following is a true peroxide ?

Options

A. `PbO_2`
B. `CO_2`
C. `SO_2`
D. `BaO_2`

Answer

To determine which of the given compounds is a true peroxide, we need to identify the presence of a peroxy linkage. A true peroxide contains the peroxy linkage, which is characterized by the presence of an O-O single bond (peroxide bond) and has the formula O2^2-.

Let's analyze the options step by step:

### Step 1: Understanding True Peroxides
- A true peroxide must contain the peroxy linkage, which is represented as -O-O-.
- The overall charge of the peroxide ion is O2^2-.

### Step 2: Analyzing the Given Compounds
1. **Lead Peroxide (PbO2)**:
- In lead peroxide, the structure involves lead (Pb) bonded to oxygen atoms.
- The oxygen atoms are typically involved in double bonds with lead, not forming the peroxy linkage.
- Therefore, PbO2 does not contain a peroxy linkage.

2. **Carbon Dioxide (CO2)**:
- Carbon dioxide consists of carbon double bonded to two oxygen atoms.
- There is no O-O bond present, hence CO2 is not a peroxide.

3. **Sulfur Compounds (e.g., SO2)**:
- Sulfur dioxide has sulfur bonded to two oxygen atoms with double bonds.
- Similar to CO2, there is no O-O bond, so it is not a peroxide.

4. **Barium Peroxide (BaO2)**:
- In barium peroxide, barium (Ba) is bonded to two oxygen atoms.
- The structure of BaO2 allows for the formation of the peroxy linkage (-O-O-).
- This means BaO2 does contain the O-O bond and is classified as a true peroxide.

### Conclusion
From the analysis, the only compound that contains a true peroxy linkage is **Barium Peroxide (BaO2)**. Therefore, the correct answer is:

**D. Barium Peroxide (BaO2)**

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