Which of the following statements is `//` are correct ?

Options

A. Rust is `Fe_(2)O_(3)`
B. `Zn-Cu` cell is called Daniell cell
C. Saline water slows down rusting.
D. Pure metals undergo corrosion faster then impure metals.

Explanation

To determine which of the given statements are correct, we will analyze each statement one by one.

### Step 1: Analyze Statement A
**Statement A:** Rust is Fe2O3.

- Rust is commonly known as iron oxide, but it is actually hydrated ferric oxide. The correct formula for rust is Fe2O3·xH2O, where x represents the number of water molecules.
- Therefore, **Statement A is incorrect.**

### Step 2: Analyze Statement B
**Statement B:** Zinc copper cell is called Daniel cell.

- The zinc-copper cell is indeed known as the Daniel cell. In this electrochemical cell, zinc acts as the anode (where oxidation occurs) and copper acts as the cathode (where reduction occurs).
- Therefore, **Statement B is correct.**

### Step 3: Analyze Statement C
**Statement C:** Saline water slows down rusting.

- This statement is incorrect. Saline water actually accelerates the rusting process due to the presence of salts, which can enhance the conductivity of water and promote the electrochemical reactions that lead to rusting.
- Therefore, **Statement C is incorrect.**

### Step 4: Analyze Statement D
**Statement D:** Pure metals undergo corrosion faster than impure metals.

- This statement is also incorrect. Pure metals like gold, silver, and platinum are less reactive and are more resistant to corrosion compared to impure metals. Impurities can create galvanic cells that may increase the rate of corrosion.
- Therefore, **Statement D is incorrect.**

### Conclusion
After analyzing all the statements:
- **Statement A:** Incorrect
- **Statement B:** Correct
- **Statement C:** Incorrect
- **Statement D:** Incorrect

Thus, the only correct statement is **Statement B**.

### Final Answer
The correct statement is: **B. Zinc copper cell is called Daniel cell.**

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