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 protect iron against corrosion, the most suitable metal plating on it is zinc. Here’s a step-by-step explanation of the reasoning behind this choice:

### Step-by-Step Solution:

1. **Understanding Corrosion**: Corrosion of iron typically occurs when it reacts with oxygen and moisture, leading to the formation of rust (iron oxide). This process can be represented by the reaction of iron with oxygen and water.

2. **Electrochemical Series**: The electrochemical series is a list of metals arranged according to their standard electrode potentials. Metals higher in the series are more reactive and are better reducing agents, meaning they can oxidize more readily than those lower in the series.

3. **Identifying Reactivity**: In the electrochemical series, zinc (Zn) has a standard reduction potential of -0.76 V, while iron (Fe) has a standard reduction potential of -0.45 V. This indicates that zinc is more reactive than iron.

4. **Galvanization Process**: When zinc is used as a plating on iron, it acts sacrificially. This means that zinc will oxidize (corrode) before iron does, thereby protecting the iron from rusting. This process is known as galvanization.

5. **Choosing the Right Metal**: Among the options provided (copper, zinc, nickel, tin), zinc is the most suitable for plating iron because of its higher reactivity compared to iron. This ensures that zinc will corrode in place of iron, thus preventing iron from rusting.

6. **Conclusion**: Therefore, the most suitable metal plating to protect iron against corrosion is zinc plating.

### Final Answer:
The most suitable metal plating on iron to protect it against corrosion is **zinc plating**.