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Calculating Delta S for reaction

1. At two different temperatures, the reaction A & B is allowed to reach equilibrium and Delta H is measure. Delta H =10.9 kJ/mol for this reaction at 5.5 C and Delta H=31.0 kJ/mol at 80.1 C. Calculate Delta S for this reaction at each of these two temperatures. (Hint Delta G = 0 at equilibrium).

Solution Preview

Remember the Gibbs equation that relates delta H, delta G and delta S?

I'll use dH and dG and dS as abbreviations.

dG = dH - TdS

Now, at equilibrium, delta G is always = 0.


0 = dH - TdS

Let's rearrange the equation by adding TdS to each ...

Solution Summary

The solution calculates delta S for a reaction at two different temperatures. The delta G of the reaction at equilibrium is equal to zero.