Question

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

Answer 1

See above.
You don't need to post multiple times. It takes a LITTLE time to read, solve, and compose and answer for you.

Answer 2

well actually i double clicked the submit button and it posted it twice... sorry