The decrease in the freezing point of the solution is −1.86oC.
Now we know that the freezing point depression of a solid is a colligative property of the solution.
Thus we have that;
ΔT = K m i
ΔT = freezing point depression
K = freezing constant
m = molality of the solution
i = Van't Hoff factor
Thus;
molality = 1 mol/1 Kg = 1 m
ΔT = −1.86oC/m * 1 m * 1
ΔT =−1.86oC
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