Abstract
The rate of sponification of ethyl acetate by sodium hydroxide was measured near the consolute point of the liquid mixture, 2-butoxyethanol + water. At temperatures far below the lower critical solution temperature, T c, the apparent rate constant obeyed the Arrhenius equation. In the one-phase region just beneath T c, the rate constant decreased below the Arrhenius background, indicating critical slowing down. Because the kinetics of this reaction are second order, the net reaction rate depends upon both (∂ΔG/∂ξ) e and (∂ΔG/∂ξ) e , where Δ G is the Gibbs free energy difference between products and reactants, ξ is the extent of reaction, and subscript “e” refers to chemical equilibrium. On the basis of the Principle of Universality, it is argued that as the temperature approaches T c, both of these thermodynamic derivatives should go to zero, and the net reaction rate should slow down as is actually observed.
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REFERENCES
A. Findlay, A.N. Campbell, and N.O. Smith, The Phase Rule, 9th Ed. (Dover Publications, New York, 1951), Chapt.6.
J.C. Clunie and J.K. Baird, Fluid Phase Equilib. 150-151:549 (1998).
J.K. Baird and J.C. Clunie, J.Phys.Chem.A 102:6498 (1998).
E.S. Gould, Mechanism and Structure in Organic Chemistry (Holt, Rinehart, and Winston, New York, 1959)Chaps.8 and 9.
Y.W. Kim and J.K. Baird, Int.J.Thermophys. 22:1449 (2001).
Y.W. Kim and J.K. Baird, J.Phys.Chem. 107:8435 (2003).
J.K. Baird, J.Chem.Educ. 76:1146 (1999).
R.G. Griffiths and J.C. Wheeler, Phys.Rev.A 2:1047 (1970).
Y.W. Kim.Dissertation, University of Alabama in Huntsville (2000).
C.-H. Shaw and W.I. Goldburg, J.Chem.Phys. 65:4906 (1976).
J.F. Counsell, D.H. Everett, and R.J. Munn, Pure Appl.Chem.. 2:335 (1961).
J.C. Wheeler and R.G. Petschek, Phys.Rev.A 28:2442 (1983).
J. March, Advanced Organic Chemistry, 4th Ed. (John Wiley, New York, 1992), pp.298–305.
C.A. VanderWerf, Acids, Bases, and the Chemistry of the Covalent Bond (Reinhold Publishing Corp., New York, 1961).
S.C. Greer and M.R. Moldover, Annu.Rev.Phys.Chem. 32:233 (1981).
J.V. Sengers and J.M.H. Levelt-Sengers, Annu.Rev.Phys.Chem. 37:189 (1986).
J.K. Baird and Y.W. Kim, J.Phys.Chem. 107:10241 (2003).
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Kim, Y.W., Baird, J.K. Reaction Kinetics and Critical Phenomena: Saponification of Ethyl Acetate at the Consolute Point of 2-Butoxyethanol + Water. International Journal of Thermophysics 25, 1025–1036 (2004). https://doi.org/10.1023/B:IJOT.0000038497.48181.11
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DOI: https://doi.org/10.1023/B:IJOT.0000038497.48181.11