assuming complete dissociation of the solute, how many grams of KNO3 must be added to 275 mL of water to produce a solution that freezes at -14.5 C? The freezing point for pure water is 0.0 C and is equal to 1.86 C/m .

Answer 1

delta T = i*Kf*m
where i = 2, solve for m.

m = moles/kg solvent
Solve for moles.

moles = g/molar mass
solve for grams.