Which solution has the lower freezing point?
90.0 g CH3OH in 100. g H2O
180.0 g CH3CH2OH in 200. g H2O
I have worked this problem for someone within the last 3-4 days.
delta T = kf m
kf is not needed for this problem.
change 90 g CH3OH and 180 g CH3CH2OH to mols. Change 100 gH2O to kg (0.1 kg) and 200 g H2O to kg (0.2 kg).
Then m = molality = mols/kg.
The one with the largest delta T will have the lower freezing point.