Solubility of a solid in a liquid
 
Ionic compounds are soluble in polar solvents, e.g., NaCl, KCl, MgCl2, CaCl2 are soluble in water because they ionize in aqueous solution. Ionic compounds are insoluble in organic solvents because they do not ionize in organic solvents. Sugar, glucose, alcohol, urea are soluble in water because they can form H – bonds with water. The se compounds are soluble in organic solvents like benzene, toluene, etc.
 
In general ‘ like dissolves like’ that is polar compounds are soluble in polar solvents and non – polar compounds are soluble in non – polar solvents.
 
Effect of temperature
 
The solubility of solid in liquid increases with increase in temperature if dissolution is endothermic.
 
If dissolution is exothermic, the solubility of solid in liquid decreases with increase in temperature.
 
Effect of pressure
 
The solubility of solid in liquid is not affected significantly by pressure because solids and liquids cannot be compresses,