When 243. g of urea (CH4N2O) are dissolved in 1300.g of a certain mystery liquid X, the freezing point of the solution is 7.30C less than the freezing poin of pure X. Calculate the mass of ammonium chloride (NH4Cl) that must be dissolved in the same mass of X to produce the same depression in freezing point. The van't Holf factor i=1.80 for ammonium chloride in X. Be sure your answer has a unit symbol, if necessary, and round your answer to 3 significant digits