Question

solute crystals are added to a solution until they begin to sink to the bottom of their container. the solution is then heated, and many more solute crystals dissolve. which term best describes the solution immediately after it was heated?
○ saturated
○ unsaturated
○ concentrated
○ supersaturated

Explanation:

1. Initially, when solute crystals sank, the solution was saturated (couldn't dissolve more at that temp).
2. Heating increased the solution's solubility, and more solute dissolved. A supersaturated solution holds more solute than a saturated solution at a given temperature (here, after heating, it has more dissolved solute than the saturated amount at the original temp, and since heating allowed more to dissolve beyond the initial saturation, it's supersaturated immediately after heating).
3. "Unsaturated" can still dissolve more (but here we added more than original saturation after heating), "concentrated" is a general term about solute amount (not specific to solubility limits), and "saturated" can't dissolve more at that temp (but we just dissolved more via heating, so it's beyond saturated).

Answer:

D. supersaturated