Which one of the following statements is false O AG7 of elements in their standard states is zero O The entropy of a substance in the liquid phase is lower than the entropy of the same substance in the gas phas O AS for vaporization of a liquid is always positive. O A spontaneous reaction in one direction is always nonspontaneous in the reverse direction. AG should be positive for a spontaneous reaction

Many plastic materials are organic polymers that contain carbon and hydrogen. The oxidation of these plastics in air to farm carbon dioxide and water is a spontaneous process; however, plastic materials tend to persist in the environment. Explain.

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?

10.104 (a) When a chemical bond forms, what happens to the entropy of the system? (b) Thermodynamically, what allows any bond formation to occur? (c) What do your answers to parts (a) and (b) suggest must be true about the formation of chemical bonds for the octet rule to hold?