9 grams of 90-240 Jim grain-size particles of gypsum in "fer de lance" were
suspended in 500 ml of reagent solution ( water, NaHC03 10-³ N), stirred in a flask at
25 cC. The suspension was sampled through the time to insure the progress of
dissolution. The dissolution curves of sol- and Ca²+, determined by chromatography
ionic, showed a difference in the magnitude of the release of these two components of
gypsum, and indicated that bicarbonate most likely enhances the dissolution. The
analyses of experimental data using Davies and Transition State Theories indicated
that the kinetic dissolution of gypsum especially in water seems to be a second order
dependent process of surface reaction. The Bovengton-Jones plot is correctly verified
for the experimental points succeeding the initial step of dissolution. The kinetic
parameters determined by the application of Transition Theory may be extended to
interpret the non adjustment of Bovengton-Jones plot in the initial stage of dissolution
as an apparent fact due to the non linearity between the net rate of reaction V_ne and
the reaction free energy ~G.