Which of the oxides is not a mixed oxide ?

Options

A. `Co(Al_() O_(2))_(2)`
B. `Mn_(3)O_(4)`
C. `Pb_(3)O_(4)`
D. `C_(3)O_(2)`

Answer

To determine which of the given oxides is not a mixed oxide, we need to understand what a mixed oxide is. A mixed oxide is formed when two different oxides combine, typically containing different oxidation states or different cations.

### Step-by-Step Solution:

1. **Understand Mixed Oxides**:
- A mixed oxide consists of two different metal oxides or two different oxidation states of the same metal.

2. **Analyze Each Option**:
- **Option A: CoAlO2 (or Al2O4)**:
- This oxide contains cobalt (Co) and aluminum (Al), which are different cations. Hence, it is a mixed oxide.
- **Option B: Mn3O4**:
- Manganese (Mn) in this oxide has different oxidation states (MnO and Mn2O3). Therefore, it is also a mixed oxide.
- **Option C: Pb3O4**:
- Lead (Pb) in this oxide has oxidation states of +2 and +4 (from PbO and PbO2). Thus, it is a mixed oxide as well.
- **Option D: C3O2**:
- This is a suboxide of carbon. It does not contain different cations or different oxidation states in the same way the others do. Therefore, it is not a mixed oxide.

3. **Conclusion**:
- After analyzing all the options, we conclude that the oxide that is not a mixed oxide is **C3O2**.

### Final Answer:
The oxide that is not a mixed oxide is **C3O2**.

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