Why do gases always tend to be less soluble in liquids as the temperature is raised?
The solubility of a gas in a liquid at a particular temperature is directly proportional to the pressure of the gas in equilibrium with the liquid at that temperature. The dissolution of a gas in a liquid is an exothermic process, that is, it is accompanied by the evolution of heat. Thus,
Gas+Solvent ⇌ Solution + Heat
Applying Le Chatelier’s principle, the increase of temperature would shift the equilibrium in the backward direction, that is, solubility would decrease. Therefore, gases always tend to be less soluble in liquids as the temperature is raised.
When gases are dissolved in water, it is accompanied by a release of heat energy, i.e., process is exothermic. When the temperature is increased, according to Lechatlier’s Principle, the equilibrium shifts in backward direction, and thus gases becomes less soluble in liquids.
Video Tutorials For All Subjects
- Solubility - Solubility of a Gas in a Liquid