Thermodynamics of the conversion of fumarate to L-(-)-malate.


Journal Article

The thermodynamics of the conversion of aqueous fumarate to L-(-)-malate has been investigated using both heat conduction microcalorimetry and a gas chromatographic method for determining equilibrium constants. The reaction was carried out in aqueous Tris-HCl buffer over the pH range 6.3-8.0, the temperature range 25-47 degrees C, and at ionic strengths varying from 0.0005 to 0.62 mol kg-1. Measured enthalpies and equilibrium ratios have been adjusted to zero ionic strength and corrected for ionization effects to obtain the following standard state values for the conversion of aqueous fumarate 2- to malate 2- at 25 degrees C: K = 4.20 +/- 0.05, delta G degrees = -3557 +/- 30 J mol-1, delta H degrees = -15670 +/- 150 J mol-1, and delta C degrees p = -36 +/- J mol-1 K-1. Equations are given which allow one to calculate the combined effects of pH and temperature on equilibrium constants and enthalpies of this reaction.

Full Text

Cited Authors

  • Gajewski, E; Goldberg, RN; Steckler, DK

Published Date

  • August 1985

Published In

Volume / Issue

  • 22 / 3

Start / End Page

  • 187 - 195

PubMed ID

  • 4052575

Pubmed Central ID

  • 4052575

Electronic International Standard Serial Number (EISSN)

  • 1873-4200

International Standard Serial Number (ISSN)

  • 0301-4622

Digital Object Identifier (DOI)

  • 10.1016/0301-4622(85)80042-9


  • eng