Solubility of Solids in Liquids

The extent to which a solute is soluble in a solvent is expressed in terms of solubility. Solubility of a substance may be defined as the amount of solute dissolved in 100gms of a solvent to form a saturated solution at a given temperature.

Solubility of a solid in a liquid depends on:

a) Nature of solvent and solute

b) Temperature.

Nature of solvent and solute

Polar solvent dissolves polar solutes and nonpolar solvents dissolve nonpolar solutes. For e.g., polar solvents like water, liquid ammonia, liquid hydrofluoric acid etc. dissolve polar and ionic compounds. Whereas nonpolar solvents like benzene, carbon disulphide, carbontetrachloride etc. dissolve nonpolar compounds.

Temperature

The substance, which dissolve in a solvent with absorption of heat (e.g., NH₄Cl, KNO₃, NaNO₃ etc.) show an increase in solubility with increase in temperature, whereas the solubility of substances which dissolve with evolution of heat (e.g. NaOH, (CH₃COO)₂Ca etc.,) show a decrease in their solubility with rise in temperature.