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Change in Gibbs

1- Calculate the change in Gibbs free energy for each of the following sets of ΔH ∘ rxn , ΔS ∘ rxn , and T .

Part A : ΔH ∘ rxn =− 122kJ ; ΔS ∘ rxn = 248J/K ; T= 298K
Part B : ΔH ∘ rxn = 122kJ ; ΔS ∘ rxn =− 248J/K ; T= 298K
Part C : ΔH ∘ rxn =− 122kJ ; ΔS ∘ rxn =− 248J/K ; T= 298K Express your answer using two significant figures.
Part D : ΔH ∘ rxn =− 122kJ ; ΔS ∘ rxn =− 248J/K ; T= 562K Express your answer using two significant figures.
Part E : Predict whether or not the reaction in part A will be spontaneous at the temperature indicated.
Part F :Predict whether or not the reaction in part B will be spontaneous at the temperature indicated.
Part G : Predict whether or not the reaction in part C will be spontaneous at the temperature indicated.
Part H :Predict whether or not the reaction in part D will be spontaneous at the temperature indicated.

Solution Preview

Change in Gibbs free energy (ΔG∘ rxn) is given as = ΔH ∘ rxn - TΔS ∘ rxn

Note: we have to convert the value of ΔH ∘ rxn from KJ to J to solve the questions.

Part A: ΔG∘ rxn = - 122000 - (298 * 248) = -195,904J or -195.90kJ (in ...

Solution Summary

The solution discusses the change in Gibbs. The expert uses Gibbs free energy to predict if a reaction is spontaneous.

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