Solubility of a solid in a liquid
- Solution of sugar or salt dissolved is a common example of solubility of a solid in liquid. But it is not necessary that all solids will dissolve in liquid.
- For instance, solids like naphthalene and anthracene do not dissolve in water but dissolves easily in benzene but sugar and salt does not dissolves in benzene.
- This is because it is property of solution that polar solutes dissolve in polar solvents like Water, ethanol, formaldehyde and chloroform whereas non polar solutes in nonpolar solvents like pyridine, toluene, and hexane. This phenomenon can be easily defined as like dissolves like.
- The phenomenon of increase in the concentration of solution due to dissolving of solid solute to the solvent is known as dissolution.
- The phenomenon of collision of solute particles in a solution resulting in the separation of the solute particles from the solution is known as crystallization.
- A phase when number of solute particles going into solution is equal to the solute particles separating out of the solution is known as equilibrium. The concentration of solute remains constant at this stage.
- A solution in which no more solute can be dissolved into the solvent at the same temperature and pressure is known as saturated solution.
- Whereas a solution in which more solute can be dissolved in the solvent at the same temperature and pressure is known as unsaturated solution.
- According to Le Chateliers Principle in a saturated solution, if the dissolution process is endothermic (Δsol H > 0), the solubility should increase with rise in temperature but if the dissolution process is exothermic (Δsol H > 0) the solubility should decrease.
- Pressure does not have crucial effect on solubility of solids in liquids because they remain unaffected to pressure due to the high incompressibility of solids and liquids.
