Freezing point of pure water = -2, Freezing point of Unknown solution = -1

Mass of unknown in 50g of water = 1.9964g. Calculate the delta T for the solution of the unknown solid and determine the molecular weight of the unknown solid.

3 answers

Freezing point is supposed to go down. It went up. Bad data. Means nothing to me.
If it had gone down then how would we calculate it
delta T = Kf*m
Substitute for delta T and Kf and solve for m = molality
In your case delta T is +1 and kg solvent is 0.050.

m = mols/kg solent
You have m and kg solvent; solve for mols.

mol = grams/molar mass. You have mol and grams, solve for molar mass.