When a solution is saturated, more solute will typically dissolve if you: _.
A. change the temperature
B. stir the solution
C. continue to add solute
D. crush or grind the solute into a fine powder
The Correct Answer and Explanation is:
The correct answer is A. change the temperature.
A saturated solution is one where no more solute can dissolve in the solvent at a given temperature and pressure. When you have a saturated solution, the solute is in dynamic equilibrium with the dissolved solute, meaning the rate at which the solute dissolves is equal to the rate at which it precipitates out of solution. Therefore, simply adding more solute (option C) will not lead to additional dissolution; instead, the excess solute will remain undissolved.
Changing the temperature of the solution can effectively increase the solubility of the solute. Most solids dissolve better at higher temperatures due to increased molecular motion, which allows more solute particles to interact with the solvent. For example, when you heat a saturated solution, the solubility of many solutes (like sugar or salt) typically increases, allowing more solute to dissolve until a new saturation point is reached. Conversely, lowering the temperature may decrease solubility, leading to precipitation of solute.
Stirring the solution (option B) can help distribute the solute particles and promote dissolution but will not increase the saturation level if the solution is already saturated. It merely helps dissolve some solute that may not be fully in contact with the solvent. Crushing or grinding the solute into a fine powder (option D) increases the surface area available for dissolution, which can help a solid dissolve more quickly but does not change the saturation point.
In summary, the most effective way to dissolve more solute in a saturated solution is to change the temperature, as this directly affects the solubility of the solute in the solvent.