Influence of Molecular Interaction on Thermal Reaction Power

4 Influence of Molecular Interaction on Thermal Reaction Power 

Because of the increase in the concentrations in the reaction mixture, the mutual influence of all the species within the mixture (reactants, intermediate products, products, by-products and solvent) becomes more and more ascertainable. This occurrence affects the thermal reaction power because the interaction sets the tone for both the enthalpy and the rate of reaction. 

To formulate the general rate function of heat release, it is convenient to represent the reactivity of mutually affected actual reactants in a concentrated mixture by virtual reactants without interacting with the surroundings. For that, in relations (4.9) and (4.10) the following replacements are made  

The molar enthalpies and the molar heat of the actual species by the 

In a concentrated mixture runs the elementary reactimi lA. The activity coefficient of reactant A does not change during the run, for example/j (ce) = konst = 0.5. The rate of reaction is, according to (4.160), r = k - a/ = k- (f/ Cs) CA.reai) = k (0.5 CA,reai)- This means that the mutual interaction acts as if in the actual mixture only half of the really present A moles originate without interaction the propelling force for the run of the reaction. The concentratirai of the virtual reactants corresponds to 0.5-CA.reai- 

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