Consider the decomposition of a metal oxide to its elements, where M represents a generic metal. 3 M₂O3(s) 2M(s) + O2(g) AG(kJ/mol) Substance M2O3(s) -6.40 M(s) 0 What is the standard change in Gibbs energy for the reaction, as written, in the forward direction? O2(g) 0 AGxn= What is the equilibrium constant of this reaction, as written, in the forward direction at 298 K? K = What is the equilibrium pressure of O2(g) over M(s) at 298 K? kJ/mol

Which contains greater entropy, a quantity of frozen benzene or the same quantity of liquid benzene at the same temperature? Explain in terms of the dispersal of energy in the substance.

Consider the reaction CO(g)+H2O(g)CO2(g)+H2(g) Use the appropriate tables to calculate (a) G at 552C (b) K at 552C

What is the sign of the standard Gibbs free-energy change at low temperatures and at high temperatures for the explosive decomposition of TNT? Use your knowledge of TNT and the chemical equation, particularly the phases, to answer this question. (Thermodynamic data for TNT are not in Appendix G.) 2C7H5N3O6(s) 3N2(g) + 5H2O() + 7C(s) + 7CO(g)

A key component in many chemical engineering designs is the separation of mixtures of chemicals. (a) What happens to the entropy of the system when a chemical mixture is separated? (b) Are designs for chemical separation more likely to rely on spontaneous or nonspontaneous processes?

The free energy change, G, for a process at constant temperature and pressure is related to Suniv and reflects the spontaneity of the process. How is G related to Suniv? When is a process spontaneous? Nonspontaneous? At equilibrium? G is a composite term composed of H, T, and S. What is the G equation? Give the four possible sign combinations for H and S. What temperatures are required for each sign combination to yield a spontaneous process? If G is positive, what does it say about the reverse process? How does the G = H TS equation reduce when at the melting-point temperature of a solid-to-liquid phase change or at the boiling-point temperature of a liquid-to-gas phase change? What is the sign of G for the solid-to-liquid phase change at temperatures above the freezing point? What is the sign of G for the liquid-to-gas phase change at temperatures below the boiling point?

Some water is placed in a coffee-cup calorimeter. When 1.0 g of an ionic solid is added, the temperature of the solution increases from 21.5C to 24.2C as the solid dissolves. For the dissolving process, what are the signs for Ssys, Ssurr, and Suniv?

Use the data in Appendix J to calculate rG andKPat 25 C for the reaction 2HBr(g)+Cl2(g)2HCl(g)+Br2() Comment on the connection between the sign of rG and the magnitude ofKP.

Consider a metal ion A2+ and its nitrate salt, In an experiment, 35.00 mL of a 0.217 M solution of A(NO3)2 is made to react with 25.00 mL of 0.195 M NaOH. A precipitate, A(OH)2, forms. Along with the precipitation, the temperature increases from 24.8C to 28.2C. What is H for the precipitation of A(OH)2? The following assumptions can be made. • The density of the solution is 1.00 g/mL. • Volumes are additive. • The specific heat of the solution is 4.18 J/g C.

A reaction has H298=100 kj/mol and S298=250 J/mol K. Is the reaction spontaneous at room temperature? If not, under what temperature conditions will it become spontaneous?