Chemical Reaction Equilibrium hrxn as a function of T

I said in my previous post that I will discuss how to solve the equilibrium constant K when the enthalpy of the reaction is not constant, but a function of temperature. That is to say:

Enthalpy as a function of temperature

If the above statement is true for the given system then you need to use the following, extremely long formula, I suggest doing this on excel or a similar program. To determine KT, the equilibrium constant at the new operating temperature, use the following equation:

KT when hrxn is a function of T

The constants A, B, C, D and E you get from the heat capacities of the different elements in the chemical reaction with:

The same goes for C, D and E

From a previous post it is shown that vi is the stoichiometric coefficient of the reaction, remember that vi of the reactants are always negative and the products coefficients are always positive, this is really just convention more than anything else.

The nature of the reaction, exothermic or endothermic, and the mole ratios on the reactant and product side of the reaction determines greatly whether K will increase or decrease at the new operation temperature. The tip I'm giving is that you should look at the hrxn, and understand what it means, this makes it easier to interpret whether your calculations are correct and in the right order.

If you have a exothermic reaction for instance and you lower the ambient temperature your product side of the reaction will be favored, and vise versa.

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