posted by jessi .
How many moles of antifreeze (a molecular substance) must be added per liter of water to protect the cooling system of a motocar to -30 degrees F.
delta T = Kf*m
Convert -30F to degrees C.
Substitute into the formula and solve for m. Since molality = moles/kg solvent that will be moles/L IF we assume 1 L of water has a mass of 1 kg.