moles FeCl3 = grams/molar mass
Solve for moles.
molality = #moles/kg solvent
Solve for molality = m
delta T = i*Kf*m
i = 4
You know m, Kf, and i, solve for delta T and subtract from the normal freezing point of water.
calculate the freezing point of 12.0g FeCl3 in 142g water...
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