How does temperature affect solute solubility?

Temperature generally increases the solubility of solid solutes in a solvent, but decreases the solubility of gases.

In more detail, the solubility of most solid solutes in a liquid solvent typically increases as the temperature of the solvent increases. This is because solubility is a process that involves breaking the bonds between solute particles and between solvent particles, which requires energy. As the temperature increases, more energy is available to break these bonds, allowing more solute to dissolve. This is why sugar, a solid solute, dissolves more readily in hot tea than in cold tea.

However, the solubility of gases in a liquid solvent usually decreases as the temperature increases. This is because gases are less likely to be attracted to the solvent particles as the temperature increases. The increased kinetic energy of the gas particles makes them more likely to escape from the solvent into the air. This is why a fizzy drink, which contains dissolved carbon dioxide gas, goes flat more quickly when it is warm than when it is cold.

It's important to note that these are general trends and there can be exceptions. For example, some solid solutes become less soluble in a solvent as the temperature increases. This is relatively rare, but it does occur in some cases. The solubility of a particular solute in a particular solvent at a particular temperature is a specific property that can be measured and recorded in solubility charts or tables.

In summary, temperature plays a crucial role in solubility. For most solids, an increase in temperature results in an increase in solubility, while for gases, an increase in temperature typically results in a decrease in solubility. Understanding these principles can help you predict and explain the behaviour of different solutes in different solvents at different temperatures.