Application of iso-temperature method of multiple rate to kinetic analysis - Dehydration for calcium oxalate monohydrate

A new method of the multiple rate iso-temperature was used to define the most probable mechanism g(alpha) of a reaction; the iterative iso-conversional procedure has been employed to estimate apparent activation energy E-a, the pre-exponential factor A was obtained on the basis of E-a and g(alpha). In this new method, the thermal analysis kinetics triplet of dehydration of calcium oxalate monohydrate is determined, which apparent activation energy E-a is 82.83 kJ mol(-1), pre-exponential factor A is 1.142 . 10(5) - 1.235 . 10(5) s(-1), the most probable mechanism belongs to phase boundary reaction R-n with integral form g(alpha)= 1 -(1 -alpha)(n) and differential form f(alpha)= n(1 -alpha)(1-(1/n)), where accommodation factor n=2.40 - 1.40.