When 252g of iron(III) nitrate (Fe(NO3)3) are dissolved in 800.0g of a certain mystery liquid X, the freezing point of the solution is 10.5C lower than the freezing point of pure X. Calculate the observed van't Hoff factor for iron(III) nitrate in X. Freezing point depression constant (Kf) for the mystery liquid X=2.8C/m Molar mass of Fe(NO3)3=241.87g/mol A1.9 B2.5 C2.9 Select the phase change of the substance that occurs when the temperature decreases from 40C to 80C at 4atm. Melting, Freezing, Deposition, Vaporization, or Sublimation A B C C D