CHEMISTRY 204 Spring 2006HOUR EXAM II page 1Consider a sample containing 1.00 mol of an ideal gas that is taken from state Ato state C by the following two step pathway: step 1 step 2PA = 2.00 atm → PB = 4.00 atm → PC = 4.00 atmVA = 10.0 L VB = 5.00 L VC = 20.0 LCalculate the following:1. (2) w1a) 0 b) 1.01 kJ c) -2.03 kJ d) -5.76 kJ e) none of these2. (2) q2a) 0 b) -6.08 kJ c) 9.12 kJ d) 15.2 kJ e) none of these3. (2) ∆HA→Ca) 0 b) -7.09 kJ c) 15.2 kJ d) 20.7 kJ e) none of these4. (2) ∆EA→Ca) 0 b) 7.09 kJ c) 9.12 kJ d) -10.17 kJ e) none of these5. (2) Separate samples of equal volumes of Ar (g), CO2 (g) and O2 (g) are at the sameinitial temperature (Ti) and pressure. The samples then absorb the same amount of heat (q). Predict the relative final temperatures (Tf) of the three samples. Lowest Tf Highest Tfa) Ar < CO2 < O2b) O2 < Ar < CO2c) CO2 < Ar < O2d) CO2 < O2 < Are) all of the Tf will be the same6. (2) The molar heat capacity at 25oC should be close to 25 J/mol K for all of the following elements excepta) Pt b) Kr c) W d) K e) NiCHEMISTRY 204 Spring 2006HOUR EXAM II page 27. (2) Predict the signs of the changes in free energy, enthalpy, entropy and the sign of work for the following process carried out at 50 K. The boiling point of N2 is 77K.N2 (g)  N2 (l)ΔGoΔHoΔSowa) + - - +b) + + + +c) + + - -d) - - + +e) - - - +8. (2) For which of the following reactions is ΔH >ΔE, when carried out in an open container and at a constant temperature?a) Zn (s) + Cu2+ (aq) → Zn2+ (aq) + Cu (s)b) C (s) + CO2 (g) → 2 CO (g)c) 2 CO (g) + O2 (g) → 2 CO2 (g)d) NO (s) → NO (l)e) 2 NO2 (g) → N2O4 (g)9. (3) Hydrogen cyanide is produced in the following reaction:2 NH3 (g) + 3 O2 (g) + 2 CH4 (g) → 2 HCN (g) + 6 H2 O (g)Given the following standard heats of formation: ΔHfo (kJ/mol)NH3 (g) -46CH4 (g) -75HCN (g) 135H2O (g) -242calculate the approximate ΔH of this reaction.a) 500 kJ b) - 500 kJ c) -1000 kJ d) -1500 kJe) not enough information is given to make the calculationCHEMISTRY 204 Spring 2006HOUR EXAM II page 310. (3) Hydrogen cyanide can also be formed in the following reaction for which H = 158 kJ:CHHHNHHCH N+2H HGiven the following bond energies, calculate the bond energy of the H-H bond.bond energy (kJ/mol)H-C 413H-N 391C-N 305CN 89111. (3) Given:Cu2O (s) + ½ O2 (g) → 2 CuO (s) ΔHo = -144 kJ2 Cu2O (s) → 2 Cu (s) + 2 CuO(s) ΔHo = 22 kJCalculate the standard enthalpy of formation of CuO (s).a) -166 kJ/mol b) 166 kJ/mol c) 299 kJ/mol d) 155 kJ/mole) -155 kJ/mol12. (3) A blacksmith throws an iron horse shoe weighing 560 g and at a temperature of 1100oC into a bucket containing 1.0 L of 25oC water. Given that the specific heat capacity of iron is 0.44 J/goC, what is the final state of the water?(Cwater = 4.184 J/goC, Csteam = 1.996 J/goC, ΔHvap water = 40.7 kJ/mol).a) water at 79oC b) water at 85oC c) water at 98oCd) a mixture of water and steam at 100oC e) steam at 102oC13. (2) Which of the following statements is true if the reaction quotient is equal to 1?a) ΔG = 0 b) ΔGo = 0 c) ΔSo = 0 d) ΔG = ΔGoe) ΔHo = TΔSoa) 316 kJb) 207 kJc) 432 kJd) 158 kJe) 864 kJCHEMISTRY 204 Spring 2006HOUR EXAM II page 414. (2) The figure, below, shows one of several possible configurations for a set of twoidentical molecules that can occupy any of the three energy levels. What is the most probable total energy of this system? (Hint: draw all of the microstates.) E = 2E = 1E = 015. (2) What is the entropy of this system? (kB = Boltzmann constant)a) 0.69kBb) 1.10kBc) 1.39kBd) 1.61kBe) 1.79 kB16. (2) Phosphorous, P, can exist in two different forms, Pred and Pwhite, which are stable at different temperatures. The heat of formation of Pred is -18.4 kJ/mol. Which form of phosphorous has the more ordered crystal structure?a) Predb) Pwhitec) more information is needed to decide17. (3) Calculate the standard enthalpy of formation of Br2 (g) from the following data for the vaporization reaction which occurs at 332.5 K.Br2 (l) → Br2 (g) So (J/mol K)Br2 (l) 152Br2 (g) 245a) 30.92 kJ/mol b) 3092 .2 kJ/mol c) 279.6 kJ/mold) 0.279 kJ/mol e) 35.19 kJ/mol18. (2) Consider the formation of hydrogen free radicals:H2 (g)  2 H. (g)Predict the proper signs of ∆Go, ∆Ho and ∆So for this process.∆Ho∆So ∆Go high T low Ta) 0b) 1c) 2d) 3e) 4CHEMISTRY 204 Spring 2006HOUR EXAM II page 5a) - - - +b) - - + -c) - + + -d) + + + -e) + + - +One mole of an ideal gas, with an initial volume of 1.500 L and an initial pressure of 30.00 atm is contained in a vessel with a movable piston. The external pressure is decreased to 15.00 atm and the gas is allowed to expand isothermally, in a 1 step process. Calculate:19. (2) wa) 0 b) -2.28 kJ c) -4.56 kJ d) -22.5 kJ e) none of these20. (2) qa) 0 b) 2.28 kJ c) 4.56 kJ d) 22.5 kJ e) none of these21. (2) Sa) 0 b) 4.16 J/K c) 5.76 J/K d) 16.9 J/K e) none of these22. (2) Ssurra) 0 b) -3.23 J/K c) -4.16 J/K d) -5.76 J/K e) none of these23. (2) Suniv a) 0 b) 0.93 J/K c) 2.53 J/K d) 1.60 J/K e) none of these24. (2) Ea) 0 b) -2.28 kJ c) -4.56 kJ d) -22.5 kJ e) none of these25. (2) Ha) 0 b) 2.28 kJ c) 4.56 kJ d) 22.5 kJ e) none of these26. (2) G a) 0 b) -3.16 kJ c) -2.28 kJ d) -9.27 kJ e) none of theseCHEMISTRY 204