We’re being asked to determine the solution will have the lowest freezing point.
Recall that the freezing point of a solution is lower than that of the pure solvent and the change in freezing point (ΔTf) is given by:
The change in freezing point is also related to the molality of the solution:
i = van’t Hoff factor
m = molality of the solution (in m or mol/kg)
Kf = freezing point depression constant (in ˚C/m)
The solution with the highest change in freezing point (ΔTf) will be the solution with the lowest freezing point.
Which of the following solutions will have the lowest freezing point? Input the appropriate letter.
A. 35.0 g of C3H8O in 250.0 g of ethanol (C2H5OH)
B. 35.0 g of C4H10O in 250.0 g of ethanol (C2H5OH)
C. 35.0 g of C2H6O2 in 250.0 g of ethanol (C2H5OH)