Effect of MgCl2 and CaCl2 on the bubble point of mixed solvent (Toluene-lsopropyl Alcohol-H2O System)

  • Noel P. Cabigon Chemical Engineering Department, De La Salle University-Manila, Manila
  • Nathaniel P. Dugos Chemical Engineering Department, Adamson University, Manila
Keywords: bubble point, azeotrope, salt effect, molecular affinity


This study presents the effect of adding alkaline earth metal halides on the boiling points of mixed solvents (i.e toluene-isopropyl alcohol-water system). The objective is to determine the effect of the salts on the selective separation of the solvents at azeotropic point. A comparison is made on two common Group IIA salts, CaCl2 and MgCl2. This comparison helps in setting the criteria for the economic viability of the technology and in setting options for the implementation of the technology. Though the research has been expanded to several types of solvent systems, this paper will present only the mixture of toluene, isopropyl alcohol and water.

Results showed that mixed solvents added with CaCl2 boil at higher temperatures than those with MgCl2 even though the latter salt is higher in molal concentration. This proves that MgCl2, which is more electronegative than CaCl2 is more effective in reducing the molecular affinity to polar and associating solvents (water and isopropyl alcohol) than to nonpolar solvent (toluene). The mixed solvent added with MgCl2 registered higher boiling point deviation than those with CaCl2 though both showed positive deviations. Either of the two can be effectively used and the data imply that shorter distillation tower can be used. Though the difference in temperature deviations of the two saits is statistically insignificant, a difference of one degree is economically significant considering the cost of energy.

How to Cite
Cabigon, N. P., & Dugos, N. P. (1). Effect of MgCl2 and CaCl2 on the bubble point of mixed solvent (Toluene-lsopropyl Alcohol-H2O System). KIMIKA, 20(1), 37-41. https://doi.org/10.26534/kimika.v20i1.37-41
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