The Lowest freezing point= 0.34 m urea
the highest freezing point= 0.14m MnBr2
second lowest freezing point= 0.10m AlCl3
third lowest freezing point= 0.12m CuCl2
Step-by-step explanation:
The freezing point depression can be calculated from the formula:
T f = i*K *fm ( ΔTf is the freezing point depression, i is van't Hoff factor, Kf is the freezing point depression constant for the solvent
Van't Hoff factor is no of ions involved in reaction, for non electrolytes it is one
T of water = 1.86 degrees kg/ mole
so, 0.14 MnBr2
T= 1.86*3*0.14
= 0.7812
T of 0.12 CuCl2
T= 1.86*3* 0.12
= 0.6696
T of 0.10 Alcl3
T = 1.86*4*0.10
T= 0.744
T = 1.86*1*0.34
T = 0.6324