`CaSO_(3)darr+H_(2)SO_(4)toCaSO_(4)+SO_(2)uarr+H_(2)O`

Options

A. For precipitate formation reaction
B. For precipitate dissolution reaction
C. For precipitate exchange reaction
D. For no reaction

Answer

To analyze the given reaction and determine the correct type of reaction, we can break it down step by step.

### Step 1: Identify the Reactants and Products
The reaction provided is:
\[ \text{CaSO}_3 \downarrow + \text{H}_2\text{SO}_4 \rightarrow \text{CaSO}_4 + \text{SO}_2 \uparrow + \text{H}_2\text{O} \]

- **Reactants**: Calcium sulfite (CaSO₃) and sulfuric acid (H₂SO₄).
- **Products**: Calcium sulfate (CaSO₄), sulfur dioxide (SO₂), and water (H₂O).

### Step 2: Analyze the State of Reactants and Products
- **CaSO₃** is indicated with a downward arrow, which means it is a precipitate (solid).
- **H₂SO₄** is typically a liquid.
- **CaSO₄** is usually soluble in water but can precipitate under certain conditions.
- **SO₂** is a gas (indicated by the upward arrow).
- **H₂O** is a liquid.

### Step 3: Determine the Type of Reaction
Now, we need to classify the reaction based on the presence of precipitates and their states before and after the reaction.

1. **Precipitate Formation Reaction**: This would require a new precipitate to form from reactants that did not contain one. In this case, CaSO₃ is already a precipitate, and CaSO₄ is not necessarily a precipitate in this context. Thus, this option is not applicable.

2. **Precipitate Dissolution Reaction**: This reaction suggests that a precipitate present in the reactants dissolves into the solution, resulting in no precipitate in the products. Here, CaSO₃ (the precipitate) is present in the reactants, and after the reaction, it is converted into soluble products (CaSO₄, SO₂ gas, and water). This fits the definition of a precipitate dissolution reaction.

3. **Precipitate Exchange Reaction**: This would require precipitates to be present on both sides of the reaction. Since CaSO₃ is the only precipitate in the reactants and there is no precipitate in the products, this option is not applicable.

4. **No Reaction**: This option is not valid as there is a clear reaction taking place.

### Conclusion
Based on the analysis, the correct classification for the reaction is:
**Option B: Precipitate Dissolution Reaction**.