Rate laws continued decomposition

Such differences can be attributed to differences in starting material and experimental conditions and techniques. Further it should be born in mind that thermal decomposition processes occur along complex mechanisms that cannot adequately be described by a simple rate law. This explains why apparent energies of activation or reaction orders can vary almost continuously with experimental conditions. 

During the decomposition of hydrogen peroxide, a continuous increase in pH occurs confirming the liberation of OH ions as suggested by the above mechanism. Step (5) is slow and constitutes the rate-determining step. On the basis of the above mechanism the rate law may be written as ... 

Kinetic study may describe decomposition, generally using first-order models and a reaction rate parameter linked to temperatme by the Arrhenius law. Closer scrutiny reveals a more complex behaviom, with kinetic parameters that continuously evolve with experimental conditions. These stndies yield values for activation energy ranging... 

Thus, the decomposition kinetics of carbonates are in full agreement with the theoretical concepts based on the CDV mechanism. The analysis shows that long-term discussions concerning the decomposition mechanism and the influence of the experimental conditions (in particular, the presence of CO2) on the reaction rate, initiated 70 years ago in a well-known paper by Zawadzki and Bretsznajder [114] and continuing up to now [108], are chiefly associated with the fundamental limitations of the Arrhenius plot and second-law methods used for estimating the kinetic parameters. 

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