Considering Ellingham diagram, which of the following metals can be used to reduce alumina?
(a)Mg
(b)Zn
(c)Fe
(d)Cu

Options

A. Mg
B. Zn
C. Fe
D. Cu

Explanation

To determine which metal can be used to reduce alumina (Al2O3) based on the Ellingham diagram, we will follow these steps:

### Step 1: Understand the Ellingham Diagram
The Ellingham diagram plots the Gibbs free energy change (ΔG) for various reactions against temperature. The lower the ΔG value, the more favorable the reaction is for reduction.

### Step 2: Identify the Metals and Their Positions
In the Ellingham diagram, we need to look at the positions of the metals in relation to the aluminum curve:
- Magnesium (Mg)
- Zinc (Zn)
- Iron (Fe)
- Copper (Cu)

### Step 3: Compare the Gibbs Free Energy Values
From the Ellingham diagram:
- Magnesium has the most negative ΔG, indicating it is a strong reducing agent.
- Aluminum is next, followed by Zinc, Iron, and Copper, which have progressively less negative ΔG values.

### Step 4: Determine Reducing Power
The reducing power of a metal is related to its position in the Ellingham diagram. A metal can reduce another metal oxide if it is positioned lower (more negative ΔG) than the metal oxide being reduced.

### Step 5: Conclusion
Since magnesium has the most negative ΔG value, it can effectively reduce alumina (Al2O3) by being oxidized itself. The other metals (Zn, Fe, Cu) have less reducing power compared to magnesium and cannot reduce alumina.

### Final Answer
Thus, the metal that can be used to reduce alumina is:
**(a) Mg**

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