5. What is the reduction potential for this half cell: Ag Ag+ (105 M);EAg+,Ag = 0.80 V. (A) 0.80 V (B) 1.3 V (C) 0.5 V (D) 0.50 V 6. Calculate Kp for this equilibrium at 450 C: H2(g) + I2(g) 2HI(g), when the equilibrium concentrations of H2(g) = 0.17 M, I2(g) = 0.17 M, and HI(g) = 3.34 M at the same temperature. (A) 1.5 105 (B) 9.0 108 (C) 2.3 106 (D) 386 7. Calculate Gibbs energy (G) at 25 C for the reaction: ZnS(s) + 1.5 O2(g) ZnO(s) + SO2(g). Given that the partial pressures of O2(g) = 1.7 atm, and SO2(g) = 0.15 atm, and Gf (ZnS(s)) = 147 kJ mol1, Gf (ZnO(s)) = 318 kJ mol1, Gf (SO2(g)) = 300 kJ mol1. (A) 478 kJ mol1 (B) 6491 kJ mol1 (C) 7135 kJ mol1 (D) 454 kJ mol1 8. Calculate the standard Gibbs energy change at 600 K for the reaction: N2O4(g) 2NO2(g). Given that Gf(N2O4(g)) = +97.9 kJ mol1, Gf(NO2(g)) = +51.3 kJ mol1, Hf(N2O4(g)) = +9.2 kJ mol1, and Hf(NO2(g)) = +33.3 kJ mol1 at 298 K. (A) 30.8 kJ (B) 48.6 kJ (C) 67.5 kJ (D) + 67.5 kJ 9. Calculate Ssystem when the state of 1.0 mol of gas (Cp,m=3.5R), is changed from 25 C and 1.50 atm to 135 C and 7.00 atm. (A) 71.4 J/K (B) + 71.4 J/K (C) 35.7 J/K (D) 54 J/K 10. Calculate the molar entropy of a constant-volume sample of argon at 250 K given that it is 154.84 J K1mol1 at 298 K; the molar constant-volume heat capacity of argon is 1.5R. (A) +153 J mol1K1 (B) +165 J mol1K1 (C) 165 J mol1K1 (D) 153 J mol1K1 11.Given the following two thermochemical equations: (1) 2H2(g) + O2(g) 2H2O(l) Hrxn = 572 kJ (2) H2(g) + O2(g) H2O2(l) Hrxn = 188 kJ What is the enthalpy change for the reaction: (3) 2H2O2(l) 2H2O(l) + O2(g) ? (A) 102 kJ (B) +102 kJ (C) 196 kJ (D) 672 kJ 12. What is the correct thermodynamic equation of formation of ethanol CH3CH2OH(l)? (Answer: A) (A) 2C(graphite) + 3H2(g) + O2(g) CH3CH2OH(l) (B) 4C(graphite) + 6H2(g) + O2(g) 2CH3CH2OH(l) (C) CH3CH2OH(l) 2C(graphite) + 3H2(g) + O(g) (D) 2C(graphite) + 3H2(g) + O(g) CH3CH2OH(l)