5.6 Solubility

The solubility of a substance is the maximum amount of solute that can be dissolved in an amount of solvent at a certain temperature. Therefore, it describes the concentration of a saturated solution. Solubility changes with temperature.

Table 5.1: Aqueous solubilities (g/100g) of some salts at various temperatures
Substance 10 °C 25 °C 50 °C
LiCl 73.8 84.5 94.1
NaCl 32.7 36 36.7
KCl 30.9 35.5 43
NaOH 63.9 100 170.3


Plot


Temperature affects solubility. If solubility increases with increasing temperature, the dissolution process is endothermic. If solubility decreases with increasing temperature, the dissolution process is exothermic.