To protect iron against corrosion, the most suitable metal plating on it, is

Options

A. Copper plating
B. Zinc plating
C. Nickel plating
D. Tin plating

Answer

To determine the most suitable metal plating to protect iron against corrosion, we need to analyze the reactivity of the metals in question.

### Step-by-Step Solution:

1. **Identify the Metals**: The metals mentioned for plating are copper, zinc, nickel, and tin.

2. **Understand Corrosion**: Corrosion occurs when a metal reacts with its environment, leading to deterioration. To protect iron from corrosion, we need a metal that will corrode in preference to iron.

3. **Reactivity Series**: Metals can be arranged in a reactivity series, which indicates their tendency to lose electrons (oxidize). A more reactive metal will oxidize before a less reactive metal.

4. **Electrode Potentials**: The standard electrode potential (E°) values can help us determine which metal is more reactive. A lower (more negative) E° value indicates a greater tendency to oxidize.

5. **Compare E° Values**:
- Zinc (Zn): E° = -0.76 V
- Iron (Fe): E° = -0.44 V
- Copper (Cu): E° = +0.34 V
- Nickel (Ni): E° = -0.25 V
- Tin (Sn): E° = -0.14 V

6. **Determine the Most Suitable Metal**:
- Zinc has a more negative E° value than iron, which means zinc is more reactive and will oxidize before iron.
- Therefore, zinc will corrode and protect iron from rusting.

7. **Conclusion**: The most suitable metal plating to protect iron against corrosion is **zinc plating**.

### Final Answer:
Zinc plating is the most suitable option to protect iron against corrosion.

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