Vapor-liquid equilibrium data of methanol-1, 4-dioxane-NaSCN, methanol-1, 4-dioxane-NaI and methanol-tetrahydrofuran-LiCl, and methanol-tetrahydrofuran-CuCl2 systems were measured with modified Rose still at 101.33kPa. The linear relationship between boiling temperature and salt concentration was verified by the experimental results and thermodynamical theory. The salt effect parameters at each binary composition were calculated. We analysed the reasons of "abnormal phenomena" observed in the experiment and probed into the interactions between the particles in solutions. Some important conclusions were obtained by the aid of the phase rule, salt effect theory, electrostatic theory and solvation model.

Key words: METHANOL, VAPOR LIQUID EQUILIBRIUM, TETRAHYDROFURAN, COPPER CHLORIDE, POTASSIUM CHLORIDE, DIOXANE, SALT EFFECT, LINEAR AMPLIFIER