The solubility of `CaSO_(4)`

Options

A. increase with increase in temperature
B. decrease with increase in temperature
C. increase and then decrease with increase in temperature
D. decrease and then increase with increase in temperature

Answer

To determine the solubility of calcium sulfate (CaSO₄) with respect to temperature, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Solubility**:
- Solubility refers to the maximum amount of a substance (solute) that can dissolve in a solvent (usually water) at a given temperature.

2. **Effect of Temperature on Solubility**:
- Generally, the solubility of most solids increases with an increase in temperature. However, there are exceptions to this rule.

3. **Le Chatelier's Principle**:
- According to Le Chatelier's Principle, if a system at equilibrium is subjected to a change in temperature, pressure, or concentration, the system will adjust to counteract the change and restore a new equilibrium.

4. **Applying Le Chatelier's Principle to CaSO₄**:
- When the temperature increases, the system experiences stress due to the added heat. For CaSO₄, this stress can lead to a shift in the equilibrium.

5. **Shift in Equilibrium**:
- In the case of CaSO₄, the increase in temperature causes the equilibrium to shift towards the reactant side (the solid form of CaSO₄). This means that the solubility of CaSO₄ will decrease as the temperature increases.

6. **Conclusion**:
- Therefore, the solubility of CaSO₄ decreases with an increase in temperature.

### Final Answer:
The solubility of CaSO₄ decreases with an increase in temperature.