What are the factors that affect solubility?

Solubility may be defined as the maximum amount of a substance that can dissolve in a given amount of solvent at a specific temperature. The three main factors that affect solubility are temperature, pressure, and solute-solvent interactions.  

Effect of Temperature on Solubility 

Temperature has a direct effect on solubility. Generally, increasing the temperature increases the soluble property of a solute. This is because particles of a substance move faster as the temperature increases. The faster movement increases the chances of the particles interacting with more of the solvent particles. This increases the rate at which the solution can be prepared. 

In some cases, temperature also increases the amount of solute that can be dissolved in a solvent. This is because intermolecular forces are more easily broken at higher temperatures, creating a stronger attraction between the solute particles and solvent particles. In some cases, however, change in temperature has negligible effect on how much solute can be dissolved in a specific solvent. 

Temperature has the opposite effect on solubility of gases. As the temperature increases, gases become less soluble in each other and in water, but more soluble in organic solvents.

Effect of Pressure on Solubility

Pressure affects the solubility of gasses in liquid but has no effect on the solubility of solids or liquid solutes. The solubility of gas is directly proportional to the pressure of the gases. When pressure is applied to gas that is above the surface of a solvent, the gas gets forced into the solvent where it occupies some of the spaces between the solvent particles. This increases its solubility. The effect of pressure on solubility can be seen in carbonated water, where the CO2 molecules are forced into the soda when pressure is applied. 

Effect of Solute-Solvent Interactions on Solubility

The interactions between the solute and solvent also affects solubility. Strong interactions between solute and solvent result in greater solubility while weak interactions result in lesser solubility.