The correct option is Saturated solution.
Explanation
A solution is a homogeneous mixture composed of a solute dissolved in a solvent. The capacity of a solvent to dissolve a solute depends on the nature of the substances and the temperature. Solubility is defined as the maximum amount of solute that can be dissolved in a specified amount of solvent at a constant temperature.
Analysis of Options:
- Saturated solution Saturated solution (Correct): A solution is termed saturated when it contains the maximum amount of solute capable of being dissolved at a given temperature. At this stage, the solution is in dynamic equilibrium with the undissolved solute, and no further solute can be dissolved without changing the temperature.
- Unsaturated solution Unsaturated solution (Incorrect): An unsaturated solution is one in which the amount of dissolved solute is less than the saturation level. Consequently, more solute can still be dissolved in the solvent at that specific temperature.
- Dilute solution Dilute solution (Incorrect): This is a qualitative term indicating that the solution contains a relatively small amount of solute compared to the solvent. A dilute solution can be either saturated or unsaturated depending on the solubility of the specific solute.
- Colloidal solution Colloidal solution (Incorrect): A colloid is a heterogeneous mixture where particle size is intermediate between a true solution and a suspension. It is defined by particle size (1 to 1000 nm) rather than the saturation limit of solubility.
Key Takeaway:
A saturated solution represents the limit of solubility at a specific temperature, where the rate of dissolution equals the rate of crystallization.