2.2.3 Raoult's law Consider a solution of volatile solvent. A. and nonelectrolyte solute, B, which may be volatile or nonvolatile. According to Raoult's law, the partial pressure of solvent, PA, over a solution equals the vapor pressure of the pure solvent, PA, times the mole fraction of solvent, xA, in the solution. So PA PAXA Ap-pa 0-PA -PAPAXA-PA AConsider a solution of volatile solvent, A, and nonelectrolyte solute, B, which may be volatile or nonvolatile. According to Raoult’s law, the partial pressure of solvent, pA , over a solution equals the vapor pressure of the pure solvent, PA 0 , times the mole fraction of solvent, xA , in the solution. So 2.2.3 Raoult’s law p = pA 0 - pA pA = pA 0 ·xA = pA 0 - pA 0 · xA= pA 0 (1- xA )