28. 根據 Raoult's law，哪個陳述是錯誤? (A)The vapor pressure of a solvent over a solution decreases as its mole fraction increases. (B) The solubility of a gas increases as the temperature decreases. (C) The vapor pressure of a solvent over a solution is less than that of pure solvent. (D)The greater the pressure of a gas over a solution the greater its solubility. (E) Ionic solutes dissociate in solution causing an enhancement of all colligative properties.