Which of the following metal forms anode mud during electrolytic refining of copper ?

Options

A. Zn
B. Fe
C. Ag
D. Ni

Answer

To determine which metal forms anode mud during the electrolytic refining of copper, let's analyze the process step by step.

### Step-by-Step Solution:

1. **Understanding Electrolytic Refining**:
- Electrolytic refining is a technique used to purify metals. In this process, an impure metal (in this case, copper) is used as the anode, and pure metal is deposited at the cathode.

2. **Identifying the Metals Involved**:
- The question provides a list of metals: zinc (Zn), iron (Fe), silver (Ag), and nickel (Ni). We need to determine which of these metals will form anode mud.

3. **Behavior of Metals During Electrolytic Refining**:
- In electrolytic refining, more electropositive metals (like zinc, iron, and nickel) tend to dissolve into the electrolyte solution.
- Less electropositive or precious metals (like silver, gold, platinum, etc.) do not dissolve as readily and instead collect below the anode.

4. **Formation of Anode Mud**:
- The term "anode mud" refers to the collection of less reactive metals that settle at the bottom of the electrolytic cell during the refining process.
- Since silver (Ag) is a precious metal and less reactive compared to zinc, iron, and nickel, it will not dissolve in the solution but will instead accumulate as anode mud.

5. **Conclusion**:
- Therefore, the metal that forms anode mud during the electrolytic refining of copper is silver (Ag).

### Final Answer:
The metal that forms anode mud during the electrolytic refining of copper is **silver (Ag)**.

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