You are asked to prepare a temperature bath that freezes at -25 degrees C, using only water and ammonium sulfate.
a. How many grams of ammonium sulfate would you need to prepare this bath if you start with 500 grams of water?
b. What would the boiling point (degrees C) of this solution be?
delta T = i*Kf*m
Plug in delta T, i = 2, and Kf and solv for m.
m = mols/kg solvent
Substitute and solve for mols.
mol = grams/molar mass. You know molar mass and mols, solve for grams.