Increase of Reaction Enthalpy with Temperature

As an example. Table 8.2 presents calculated and experimental data for the decomposition of CaCOa. Equation8.4 has been used in estimations of the coefficient t. As can be seen from the table, the temperature rise from 900 to 1,200 K is accompanied by an increase in the magnitude of A Hf by about 50 kJ mol instead of the expected decrease of 10 kJ moP, which considerably exceeds the measurement error. Theoretical results are confirmed quite well by experiments. (Additional results for the decompositions of CaCOs and SrCOa, supporting this effect, are presented in Sect. 16.14.) 

An increase of the true value of with temperature decreases the slope 

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