Solute-solvent, henry law, rault law, Dalton law , ideal and non-ideal solution, colligative properties and its types.i.e relative lowering in vapour pressure , elevation in boiling point ( Kb= molal elevation constant ) , lowering in freezing point ( Kf = molal depression constant), and osmotic pressure will be discussed in this session . students who are preparing for 12th science stream can find it helpfull and they can apply these concepts in numerical. Students preparing for any competitive exam can also get it more helpfull as its in their curriculum.