Using standard free energies of formation, calculate ΔG° at 25 °C...

Question

Using standard free energies of formation, calculate ΔG° at 25 °C for each reaction in Problem 62. How do the values of ΔG° calculated this way compare to those calculated from ΔH° and ΔS°? Which of the two methods can determine how ΔG° changes with temperature?

Accepted Answer

Identify the chemical reactions from Problem 62 for which you need to calculate $ \Delta G^\circ $.. Use the standard free energies of formation $ \Delta G_f^\circ $ for each reactant and product to calculate $ \Delta G^\circ $ for the reaction using the formula: $ \Delta G^\circ = \sum \Delta G_f^\circ (\text{products}) - \sum \Delta G_f^\circ (\text{reactants}) $.. Compare the $ \Delta G^\circ $ values obtained from the standard free energies of formation with those calculated using the equation $ \Delta G^\circ = \Delta H^\circ - T\Delta S^\circ $, where $ \Delta H^\circ $ is the standard enthalpy change and $ \Delta S^\circ $ is the standard entropy change.. Discuss how the two methods compare in terms of accuracy and applicability, especially considering that the $ \Delta G^\circ = \Delta H^\circ - T\Delta S^\circ $ method can be used to determine how $ \Delta G^\circ $ changes with temperature.. Conclude which method is more suitable for predicting the temperature dependence of $ \Delta G^\circ $ and why.