Iron powder and powder of rust are taken in two containers X and Y, respectively. Dilute sulphuric acid is added to both the containers. Then

Options

A. effervescence is observed in both the containers.
B. effervescence is observed in case of X but not Y.
C. effervescence is observed in case of Y but not X.
D. no effervescence is observed in both the cases.

Explanation

To solve the question regarding the reaction of iron powder and rust powder with dilute sulfuric acid, we will analyze the situation step by step.

### Step-by-Step Solution:

1. **Identify the Substances:**
- In container X, we have iron powder (Fe).
- In container Y, we have rust powder, which is primarily iron(III) oxide (Fe₂O₃).

2. **Understanding the Reaction with Dilute Sulfuric Acid:**
- Dilute sulfuric acid (H₂SO₄) reacts differently with iron and rust.
- Iron (Fe) is a reactive metal and will react with dilute sulfuric acid to produce iron sulfate (FeSO₄) and hydrogen gas (H₂).
- The reaction can be represented as:
\[ \text{Fe} + \text{H}_2\text{SO}_4 \rightarrow \text{FeSO}_4 + \text{H}_2 \uparrow \]

3. **Reaction of Rust with Dilute Sulfuric Acid:**
- Rust (Fe₂O₃) is a more stable compound and does not react with dilute sulfuric acid in the same way that iron does.
- Therefore, when dilute sulfuric acid is added to rust powder, there is no significant reaction, and no hydrogen gas is produced.

4. **Conclusion:**
- In container X (iron powder), hydrogen gas is evolved.
- In container Y (rust powder), no hydrogen gas is evolved.

### Final Summary:
- **Container X (Iron Powder + Dilute Sulfuric Acid):** Produces hydrogen gas.
- **Container Y (Rust Powder + Dilute Sulfuric Acid):** Does not produce hydrogen gas.