Calculate the van t Hoff factor and the osmotic pressure (at 31.8C) of an aqueous solution with a molality of 0.50 molal having a solute with a molecular weight of 161.28 g/mol. The density of the solution is 1024.26 kg/m3 and freezes 1.63 C below the freezing point of water. Write your answer for osmotic pressure?

a. van t Hoff factor 1.75 , osmotic pressure 20.78

b. van t Hoff factor 20.78 , osmotic pressure 1.75

c. van t Hoff factor 1.6524 , osmotic pressure 16.32

d. c. van t Hoff factor 16.32 , osmotic pressure 1.6524