What is solubility? Give its unit and explain the factors affecting solubility of solid solute in solvent.

Solubility- The solubility of solute is its amount per unit volume of saturated solution at a specific temperature.

Unit of solubility is mol/L. Factors affecting solubility of solute in liquid solvent. 

1) Nature of solute and solvent- i) Solubility of solute in a solvent is explained as "like dissolves like. It means that compounds having similar chemical characters are readily soluble in each other.

iii) Nonpolar organic substance dissolves in nonpolar solvent. E.g. Cholesterol in benzene. iv) Sugar dissolves in water due to intermolecular Hydrogen bonding. 2) Temperature: i) Generally solubility of solid in liquid increases with increase in temperature. 

ii) Dissolution of some substances in water is exothermic process. Solubility of such substances is increased by decreasing temperature. It means they are more soluble in cold water.

e.g. CaCl2, Na2SO, etc.,

iii) Dissolution of some substances in water is endothermic process. Solubility of such substances is increased by increasing temperature. It means they are more soluble in hot water.

e.g. NH,NO,, KNO,, KBr, KCI, NaNO, etc. NOTE i) Solubilities of NaBr, NaCl

ii) Solubilities of KNO,, NaNO,, and KBr increases appreciably with increasing temperature. iii) Solubilities of Na,SO, decreases with increasing

temperature. 3) Pressure Solubility of solids in liquids is not affected due to change of pressure because solids are incompressible.