According to Ellingham diagram the oxidation reaction of carbon and carbon monoxide may be used to reduce which one of the following oxides at the lowest temperature?

Options

A. `Al_(2)O_(3)`
B. `CuO`
C. `MgO`
D. `ZnO`

Explanation

To solve the question regarding which oxide can be reduced by carbon or carbon monoxide at the lowest temperature according to the Ellingham diagram, we can follow these steps:

### Step 1: Understand the Ellingham Diagram
The Ellingham diagram is a graphical representation that shows the stability of various oxides and the temperature at which they can be reduced. The lower the line on the diagram, the more stable the oxide is at that temperature.

### Step 2: Analyze Each Oxide
We need to analyze the four given oxides (Al2O3, CuO, MgO, ZnO) in relation to carbon (C) and carbon monoxide (CO) based on their positions in the Ellingham diagram.

### Step 3: Check Al2O3
- The line for Al2O3 is around -1050°C.
- The line for C is around -450°C.
- Since C is above Al2O3 on the diagram, carbon cannot reduce Al2O3.

### Step 4: Check CuO
- The line for CuO is above C.
- The reaction can be represented as CuO + C → Cu + CO2.
- Since C is below CuO on the diagram, carbon can reduce CuO.

### Step 5: Check MgO
- The line for MgO is lower than CO.
- The reaction can be represented as Mg + CO → MgO + C.
- Since CO is above MgO, carbon monoxide cannot reduce MgO.

### Step 6: Check ZnO
- The line for ZnO is around -650°C.
- The reaction can be represented as Zn + CO → ZnO + C.
- Since CO is above ZnO, carbon monoxide cannot reduce ZnO.

### Conclusion
Based on the analysis, the only oxide that can be reduced by carbon at the lowest temperature is CuO. Therefore, the correct answer is **CuO**.

### Final Answer
**CuO**

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