Final answer:
Raising the temperature of a solvent increases the kinetic energy of its molecules, leading to more frequent and forceful collisions which generally increase the solubility of solids and decrease the solubility of gases.
Step-by-step explanation:
When the temperature of a solvent is raised, the kinetic energy of the solvent molecules increases. This increase in kinetic energy results in solvent molecules moving faster and colliding with greater frequency and force. For solutes that are solid, this typically leads to an increase in solubility, as the solvent molecules are able to more effectively break apart and integrate the solute particles. In the case of gases, the opposite effect can be observed; as temperature increases, the solubility of gases like HCl, NH3, and SO2 tends to decrease.
This is because the increased kinetic energy gives the gas molecules a greater tendency to escape the solvent and return to the gas phase.