Dissolution of sodium sulphate in water is exothermic (with evolution of heat). If the temperature is raised for a saturated solution of sodium sulphate , then according to Le - Chatelier principle

Options

A. The solution will become supersaturated
B. Some solid will precipitate out from the solution
C. More solid will dissolve
D. Solution connectration will remain unchanged

Answer

To solve the question regarding the dissolution of sodium sulfate in water and the effect of temperature on a saturated solution according to Le Chatelier's principle, we can follow these steps:

### Step 1: Understand the nature of the dissolution process
- The dissolution of sodium sulfate (Na2SO4) in water is described as exothermic, meaning it releases heat when it dissolves. This is true for lower concentrations.

**Hint:** Remember that exothermic reactions release heat, while endothermic reactions absorb heat.

### Step 2: Identify the scenario of a saturated solution
- In a saturated solution, the maximum amount of solute (sodium sulfate) has dissolved in the solvent (water) at a given temperature. At this point, the rate of dissolution equals the rate of precipitation.

**Hint:** A saturated solution is at equilibrium, where the dissolution and precipitation processes occur at the same rate.

### Step 3: Apply Le Chatelier's principle
- According to Le Chatelier's principle, if a system at equilibrium is subjected to a change in conditions (like temperature), the system will adjust to counteract that change.

**Hint:** Le Chatelier's principle helps predict how a system at equilibrium will respond to changes in temperature, pressure, or concentration.

### Step 4: Analyze the effect of increasing temperature
- Since the dissolution of sodium sulfate is exothermic at lower concentrations, when the temperature is increased, the equilibrium will shift to favor the endothermic process. In this case, the dissolution of sodium sulfate becomes endothermic at saturation. Therefore, increasing the temperature will favor the dissolution of more solid sodium sulfate.

**Hint:** When temperature increases, the system will favor the process that absorbs heat (endothermic) to counteract the increase in temperature.

### Step 5: Conclusion
- As a result of raising the temperature of a saturated sodium sulfate solution, more solid sodium sulfate will dissolve, leading to a supersaturated solution.

**Final Answer:** More solid will dissolve in the saturated solution of sodium sulfate when the temperature is raised.