Humber Admissions Practice Test

What does a higher temperature generally do to the solubility of solids in liquids?

1. Increases solubility

2. Decreases solubility

3. No effect on solubility

4. Causes solubility to vary widely

The correct answer is: Increases solubility

A higher temperature generally increases the solubility of solids in liquids because, as temperature rises, the kinetic energy of the molecules within both the solute (solid) and solvent (liquid) increases. This heightened molecular movement makes it easier for the solute particles to break away from their solid structure and disperse into the solvent, leading to an increased solubility. This phenomenon is based on the principle that most solid solutes dissolve better in warmer solvents. For example, salt or sugar dissolves more easily in hot water compared to cold water. The increase in energy also helps to overcome the enthalpy of the dissolution process, which is the energy required to separate the solute's molecules from each other and integrate them into the solvent. Understanding the relationship between temperature and solubility is fundamental to many applications, from cooking to industrial processes, where temperature control can optimize the amount of solute that can be dissolved in a solution.