question_answer

Explain with suitable examples in each case why the molar masses of some substances determined with the help of colligative properties are (i) higher (ii) lower than the actual values.  

Answer:

(a) When solute undergoes association in the solutions then number of solute particles decreases. Hence molar mass determined from colligative property is lower.      e.g.     (b) When solute undergoes dissociation in solution then number of solute particles increases. Hence molar mass determined with the help of colligative property is higher.   e.g.