Which of the following is not correct?

Options

A. Rusting of iron can be stopped by increasing
the concentration of `CO_(2)` in water
B. Rusting of iron is electrochemical in nature
C. Rusting of iron takes place in moist air
D. Rusting of iron produces hydrated iron (III) oxide

Answer

To solve the question "Which of the following is not correct?" regarding the rusting of iron, we will analyze each of the provided statements one by one.

### Step-by-Step Solution:

1. **Understanding Rusting of Iron**:
- Rusting is a chemical process that occurs when iron reacts with oxygen and moisture (water) in the environment. This process is electrochemical in nature.

2. **Analyzing the Statements**:
- **Statement 1**: "Rusting of iron can be stopped by increasing the concentration of carbon dioxide in water."
- When carbon dioxide dissolves in water, it forms carbonic acid (H2CO3), which dissociates to release H+ ions. The presence of H+ ions actually promotes rusting by facilitating the oxidation of iron. Therefore, this statement is **not correct**.

- **Statement 2**: "Rusting of iron is electrochemical in nature."
- This statement is true. Rusting involves oxidation and reduction reactions, similar to those occurring in an electrochemical cell.

- **Statement 3**: "Rusting of iron takes place in moist air."
- This statement is also true. Rusting requires both oxygen (from the air) and water (moisture).

- **Statement 4**: "Rusting of iron produces hydrated ferric oxide."
- This statement is correct as well. The product of rusting is indeed hydrated iron oxide, commonly referred to as rust.

3. **Conclusion**:
- The only statement that is not correct is **Statement 1**: "Rusting of iron can be stopped by increasing the concentration of carbon dioxide in water."

### Final Answer:
The statement that is not correct is **Statement 1**.

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