Heterogeneous Chemical Equilibrium: Example Problems

Try to solve these problems before watching the solutions in the screencasts.

Example Problem 1
Given the Gibbs free energy at two temperatures, determine the maximum temperature for this heterogeneous reaction to occur:
2Ca(liq) + ThO2(crystal) ↔ 2CaO(crystal) + Th(crystal).
∆G° = -3.4 kcal/mol at 1000°C, and
∆G° = -2.0 kcal/mol at 1200°C.
Assume all phases are pure.
Example Problem 2
Calculate the equilibrium composition for this reaction to form n-heptane at 1.0-bar pressure:
7 C(s) + 8 H2(g) → C7H16(g)
The feed contains 10. mol carbon and 5.0 mol H2 .