During the process of electrolytic refining of copper some metals present as impurity settle as 'anode mud'. These are

Options

A. Sn and Ag
B. Pb and Zn
C. Ag and Au
D. Fe and Ni

Explanation

**Step-by-Step Solution:**

1. **Understanding Electrolytic Refining of Copper:**
- Electrolytic refining is a method used to purify metals, particularly copper. In this process, impure copper (blister copper) is used as the anode, and pure copper is used as the cathode.

2. **Formation of Anode Mud:**
- During the electrolytic refining process, impurities present in the blister copper do not dissolve in the electrolyte solution. Instead, they settle down at the bottom of the electrolytic cell as a residue known as 'anode mud'.

3. **Identifying Impurities:**
- The anode mud typically contains various metals that were present as impurities in the copper. Common metals found in anode mud include:
- Antimony (Sb)
- Tellurium (Te)
- Gold (Au)
- Silver (Ag)
- Platinum (Pt)
- Selenium (Se)

4. **Analyzing the Given Options:**
- The question asks for the metals that settle as anode mud during the electrolytic refining of copper.
- Among the options provided, we need to identify which metals are indeed found in anode mud.

5. **Conclusion:**
- Based on the knowledge of the composition of anode mud, silver and gold are confirmed to be present. Other metals like tin, lead, zinc, iron, and nickel are not typically found in anode mud.

6. **Final Answer:**
- Therefore, the metals that settle as anode mud during the electrolytic refining of copper are **silver and gold**.

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