6- For a certain reaction, = 45 kJ and = 125 J/K. Assume that do not vary H S Hand S with temperature. At what temperature is the reaction at equilibrium? a. b. 360 K c. d. 0.36 K 7- A reaction is spontaneous at temperatures if high a. and are both positive. b. and are both negative. ΔH ΔS ΔH ΔS c. is positive and is negative. d. is negative and is positive. ΔH ΔS ΔH ΔS 8- The equilibrium constant at 427oC for the reaction N2(g) + 3H2(g) 2NH3(g) is Kp = 9.4 10 5.  ─ Calculate the value of for the reaction at 427oC. ΔGo a. kJ b. 54 kJ c. 33 kJ d. 33 kJ ─54 ─ 9- Which of the following statements about is ΔG° FALSE? spontaneous reactions always have negative values a. ΔG° is at standard conditions (1 atm, ) b. ΔG° = c. ΔG° ΔH° spontaneous reactions are always exothermic d. 10- Consider the following reaction: 2NO(g) + N2(g) 2N2O(g) = kJ/mol ΔHo −16 Given: Sº(NO) = 210 J/molK, Sº(N2) = 190 J/molK, Sº(N2O) = 220 J/molK. At what temperature will = 0 and below which the reaction will be spontaneous? ΔGº a. 3.9 K c. 321 K d. 94 K d. 367K
6- For a certain reaction, H = 45 kJ and S = 125 J/K. Assume that Hand S do not vary with temperature. At what temperature is the reaction at equilibrium? a. b. 360 K c. d. 0.36 K 7- A reaction is spontaneous at high temperatures if a. ΔH and ΔS are both positive. b. ΔH and ΔS are both negative. c. ΔH is positive and ΔS is negative. d. ΔH is negative and ΔS is positive. 8- The equilibrium constant at 427oC for the reaction N2(g) + 3H2(g)  2NH3(g) is Kp = 9.4 10 ─ 5. Calculate the value of ΔGo for the reaction at 427oC. a. ─54 kJ b. 54 kJ c. 33 kJ d. ─ 33 kJ 9- Which of the following statements about ΔG° is FALSE? a. spontaneous reactions always have negative ΔG° values b. ΔG° is at standard conditions (1 atm, ) c. ΔG° = ΔH° d. spontaneous reactions are always exothermic 10- Consider the following reaction: 2NO(g) + N2(g) 2N2O(g) ΔHo = −16 kJ/mol Given: Sº(NO) = 210 J/molK, Sº(N2) = 190 J/molK, Sº(N2O) = 220 J/molK. At what temperature will ΔGº = 0 and below which the reaction will be spontaneous? a. 3.9 K c. 321 K d. 94 K d. 367K
homework1-8-eng.chem-soln.docx