Acta Phys. -Chim. Sin. ›› 2006, Vol. 22 ›› Issue (07): 888-890.doi: 10.3866/PKU.WHXB20060724

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Critical Crossover Phenomena in Ternary Solutions of Water+3-methylpyridine+Sodium Bromide

GAO Xue-Yi;AN Xue-Qin;WANG Nong;MA Xing-Ke;SHEN Wei-Guo   

  1. College of Chemistry & Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China; College of Chemistry and Environment Science, Nanjing Normal University, Nanjing 210097, P. R. China; Department of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China
  • Received:2005-12-19 Revised:2006-03-14 Published:2006-06-27
  • Contact: SHEN Wei-Guo

Abstract: The critical phenomena of water + 3-methylpyridine + sodium bromide system, with the mass fractions of sodium bromide, 3-methylpyridine, and water being 0.240, 0.192, and 0.568, respectively, have been studied by measuring refractive indexes in two coexisting phases. It was found that the effective critical exponent was 0.365 near the critical point, which is in well agreement with the Fisher renormalization value. As the distance from the critical point increased, the effective critical exponent decreased from 0.365 to 0.20, but it exhibited crossover from Ising to mean-field critical behavior after the regular term was subtracted.

Key words: Electrolyte solution, Critical phenomena, Critical crossover, Coexistence curve, Refractive index