Which of the following statements about colligative properties are correct? (i) In a given solvent, the fall of the freezing point of a non-electrolyte depends only on its molality. (ii) At a fixed concentration, the osmotic pressure of a non-electrolyte rises with the temperature. (iii) Any two solutes at the same molality in the same solvent give the same boiling point. (iv) A solute that splits gives an osmotic pressure lower than the calculated one.