Understanding Solubility

  • Solubility refers to the maximum amount of a solute that can be dissolved in a solvent at a given temperature.

  • This process involves the breakdown of intermolecular forces between solute particles, followed by the formation of new intermolecular attractions between the solute and solvent.

  • Most solid substances increase their solubility with an increase in temperature due to the endothermic nature of the solvation process. However, the solubility of gases usually decreases with increasing temperature.

Solubility in Ocean Waters

  • In the context of ocean chemistry, solubility is a critical concept. The solubility of gases in seawater, for example, controls the amount of oxygen and carbon dioxide available to marine life and influences the acid-base equilibrium of seawater.

  • The solubility of carbon dioxide (CO2) is particularly significant due to the critical role it plays in ocean acidification and climate regulation.

  • The solubility of a gas in seawater decreases as temperature and salinity increase whilst increasing with pressure.

Implications of Solubility Changes

  • Changes in the solubility of gases in ocean waters can have significant impacts on marine ecosystems and the global climate.

  • Decreased solubility of oxygen in warmer waters can lead to ‘ocean deoxygenation’, threatening the survival of certain marine species.

  • Increased solubility of CO2 in colder waters leads to more CO2 being stored in the oceans, contributing to ocean acidification.

  • Understanding the principles of solubility thus remains fundamental to tackling global challenges such as climate change and marine health.