31. Listed below are AH; and S° values for PCI 3, Cl2, and PCl5. Substance AH (kJ mol¹) So (J.mol-1.K-1) PC13 (g) -287 311.8 C12 (9) 0 223.1 PCl5 (g) -374.9 364.6 Use these data to calculate the equilibrium constant (Keq) for the formation of PCl5 (g) from PC|3 (g) and Cl2 (g) at 200.0°C, as shown below. A. 0.137 B. 0.155 C. 3.98 D. 6.43 E. 7.32 PC13 (g) + Cl2 (g) = PCl5 (g)

12.108 A nuclear engineer is considering the effect of discharging waste heat from a power plant into a lake and estimates that this may warm the water locally to 25 °C. One question to be considered is the effect of this temperature change on the uptake of CO2 by the water. The equilibrium constant for the reaction CO2+H2OH2CO3 ; is K=1.7103 at 25 °C. Because bonds form, the reaction is exothermic. (a) Will this reaction progress further toward products at higher temperatures near the water discharge with its warmer water than it would in the cooler lake water? Explain your reasoning. (b) Carbonic acid has a Kaof 2.5104 at 25 °C. What is the equilibrium constant for the CO2+2H2OHCO3+H3O+? (c) What additional factor should the engineer be considering about CO2 gas, probably before considering this reaction chemistry?

Hydrogen gas and iodine gas react to form hydrogen iodide. If 0.500 mol H2 and 1.00 mol I2 are placed in a closed 10.0-L vessel, what is the mole fraction of HI in the mixture when equilibrium is reached at 205C? Use data from Appendix C and any reasonable approximations to obtain K.

The reaction, 3 H2(g) + N2(g) (g), has the fol lowing equilibrium constants at the temperatures given: atT=25°C,K= 2.8 X 104 at T = 500°C, A = 2.4 X IO"7 At which temperature are reactants favored? At which temperature are products favored? YVhat can you say about the reaction if the equilibrium constant is 1.2 at 127°C?