CHM 2046C Module 13 Sample Name: __ Answers _____

Part F: Calculation ∆G^o from ∆H^o and ∆S^o 10 points

Using the quantity called the Standard Gibbs free-energy change (∆G^o), ∆G^o = ∆H^o - T∆S^o,

perform the following calculations using values in Appendix B:

Iron metal is produced commercially by reducing Iron III oxide in iron ore with

Carbon monoxide:

Fe₂O₃ (s) + 3 CO (g) ---> 2 Fe (s) + 3 CO₂ (g)

(a) Calculate the standard free-energy change for this reaction at 25^oC?

(b) Is the reaction spontaneous under standard conditions at 25^oC?

(c) Does the reverse reaction become spontaneous at higher temperature? Explain.

Worked Example 16.6 Page 665: