MHT CET202620 April 2026Morning ShiftChemistrySolutionsActual
Which from following solutions in water on complete dissociation exhibits minimum freezing point depression?
Options
- A0.2 m Potassium chloride
- B0.1 m Sodium chloride
- C0.05 m Aluminium phosphate
- D0.15 m Magnesium sulphate
Correct answer
C. 0.05 m Aluminium phosphate
Step-by-step solution
The depression in freezing point is given by T_f = i K_f m . For complete dissociation, the van't Hoff factor i is equal to the number of ions produced per formula unit. For 0.2 m Potassium chloride (KCl): i = 2 , i m = 2 0.2 = 0.4 For 0.1 m Sodium chloride (NaCl): i = 2 , i m = 2 0.1 = 0.2 For 0.05 m Aluminium phosphate (AlPO₄ ): i = 2 , i m = 2 0.05 = 0.1 For 0.15 m Magnesium sulphate (MgSO₄ ): i = 2 , i m = 2 0.15 = 0.3 Since 0.05 m Aluminium phosphate has the minimum value of i m , it exhibits the minimum freez