posted by Lauren .
Urea (NH2)2CO is dissolved in 100.0 g of water. The solution freezes at -0.085 degrees C. how many grams of urea were dissolved to make this solution.
delta T = Kf*molality
Plug in 0.085 for delta T, I assume you know Kf for water, calculate molality.
Then molality x kg solvent x molar mass = grams.
You have all but molar mass which can be calculated.
0.085 degrees C = 0 degrees C (0.1 kg/60 g of (NH2)2CO
is this right