Answer: 0.17 m : Highest freezing point
0.20 m : Second lowest freezing point
0.18 m : Third lowest freezing point
0.42 m ethylene glycol: Lowest freezing point
Explanation:
Depression in freezing point is a colligative property which depend upon the amount of the solute.
where,
= change in freezing point
i= vant hoff factor
= freezing point constant
m = molality
a) 0.17 m
For electrolytes undergoing complete dissociation, vant hoff factor is equal to the number of ions it produce. Thus i =2 for , thus total concentration will be 0.34 m
b) 0.18 m
For electrolytes undergoing complete dissociation, vant hoff factor is equal to the number of ions it produce. Thus i = 2 for , thus total concentration will be 0.36 m
c) 0.20 m
For electrolytes undergoing complete dissociation, vant hoff factor is equal to the number of ions it produce. Thus i = 2 for , thus total concentration will be 0.40 m
d) 0.42 m ethylene glycol
For non electrolytes undergoing no dissociation, vant hoff factor is equal to 1 . Thus i = 1 for ethylene glycol, thus concentration will be 0.42 m
The more is the concentration, the highest will be depression in freezing point and thus lowest will be freezing point.