Test bank chapter (14)

Transcription

1 Test bank hater (14) Choose the most orret answer 1. Whih is the orret equilibrium onstant exression for the following reation? Fe 2 O 3 (s) + 3H 2 (g) 2Fe(s) + 3H 2 O(g) a) K = [Fe 2 O 3 ] [H 2 ] 3 /[Fe] 2 [H 2 O] 3 b) K = [H 2 ]/[H 2 O] ) K = [H 2 O] 3 /[H 2 ] 3 d) K = [Fe] 2 [H 2 O] 3 /[Fe 2 O 3 ] [H 2 ] 3 2. The following reations our at 500 K. Arrange them in order of inreasing tendeny to roeed to omletion (least greatest tendeny). a) 2 < 1 < 3 b) 1 < 2 < 3 ) 2 < 3 < 1 d) 3 < 2 < 1 3.Calulate K for the reation 2NOCl(g) 2NO(g) + Cl 2 (g) at 400 C if K at 400 C for this reation is a) b) ) 0.70 d) For the reation H 2 (g) + I 2 (g) 2HI(g), K = 50.2 at 445ºC. If [H 2 ] = [I 2 ] = [HI] = M at 445ºC, whih one of these statements is true? a) The system is at equilibrium, thus no onentration hanges will our. b) The onentrations of HI and I 2 will inrease as the system aroahes equilibrium. ) The onentration of HI will inrease as the system aroahes equilibrium. d) The onentrations of H 2 and HI will fall as the system moves toward equilibrium. 5.For the following reation at equilibrium, whih hoie gives a hange that will shift the osition of equilibrium to favor formation of more roduts? 2NOBr(g) 2NO(g) + Br 2 (g), Hº rxn = 30 kj/mol a) Inrease the total ressure by dereasing the volume. b) Add more NO. ) Remove Br 2. d) Lower the temerature. 1

2 6 - For the following reation at equilibrium in a reation vessel, whih one of these hanges would ause the Br 2 onentration to derease? 2NOBr(g) 2NO(g) + Br 2 (g), Hº rxn = 30 kj/mol a) Inrease the temerature. b) Remove some NO. ) Add more NOBr. d) Comress the gas mixture into a smaller volume. 7. For the reation at equilibrium 2SO 3 2SO 2 + O 2 ( Hº rxn = 198 kj/mol), if we inrease the reation temerature, the equilibrium will a) shift to the right. b) shift to the left. ) not shift. d) The question annot be answered beause the equilibrium onstant is not given. 8. For the equilibrium reation 2SO 2 (g) + O 2 (g) 2SO 3 (g), Hº rxn = -198 kj/mol. Whih one of these fators would ause the equilibrium onstant to inrease? a) Derease the temerature. b) Add SO 2 gas. ) Remove O 2 gas. d) Add a atalyst. 9. The reation 2SO 3 (g) 2SO 2 (g) + O 2 (g) is endothermi. If the temerature is inreased a) more SO 3 will be rodued. b) K will derease. ) no hange will our in K. d) K will inrease. 10.If a atalyst is added to a hemial reation, the equilibrium yield of a rodut will be, and the time taken to ome to equilibrium will be than before. a) higher; less b) lower; the same ) higher; the same d) the same; less 11- For the reation, N 2 (g) + 3 H 2 (g) 2 NH 3 (g) K = at a ertain temerature. In an equilibrium mixture of the three gases, [NH 3 ] = M and [ H 2 ] = 1.03 M. What is the onentration of N2 in this system? a) 3.9 M b) 3.2 x 10-3 M ) 0.89 M d) 1.4 x 10-2 M 2

3 11. Consider the reation,nh 4 Cl(s) NH 3 (g) + HCl(g). If an equilibrium mixture of these three substanes is omressed, equilibrium will, beause. a) shift to the right; higher ressure favors fewer moles of gas b) shift to the right; higher ressure favors more moles of gas ) shift to the left; higher ressure favors fewer moles of gas d) shift to the left; higher ressure favors more moles of gas 12- Consider the equilibrium system; C(s) + CO2(g) 2CO(g). If more C(s) is added, the equilibrium will ; if CO is removed the equilibrium will. a) shift to the left; shift to the left b) shift to the right; shift to the right ) shift to the right; shift to the left d) be unhanged; shift to the left 8. Consider the exothermi reation at equilibrium: 2 SO 2 (g) + O 2 (g) 2 SO 3 (g), If the system is ooled, the equilibrium will, beause. a) shift to the left; dereased temerature favors an exothermi reation b) shift to the right; dereased temerature favors an exothermi reation ) shift to the right; dereased temerature favors an endothermi reation d) shift to the left; dereased temerature favors an endothermi reation 9. A large value of the equilibrium onstant indiates that when the reation reahes equilibrium, mostly will be resent. a) reatants b) roduts ) atalysts d) shranel 10. When equilibrium is ahieved a) Q > K b) Q < K ) Q = K d) Q2 = K 3

4 11. CO 2 + H 2 CO + H 2 O If all seies are gases and H 2 is added, the amount of CO resent at equilibrium will: 12. CO 2 + H 2 CO + H 2 O If all seies are gases and H 2 O is added, the amount of CO resent at equilibrium will: 13.CO 2 + H 2 CO + H 2 O If the reation is endothermi and the temerature is raised, the amount of CO resent will: 14. CO 2 + H 2 CO + H 2 O If all seies are gases and the ontainer is omressed, the amount of CO resent will: 15. CO 2 + H 2 CO + H 2 O If all seies are gases and the ontainer is omressed, the amount of CO resent will: 16. What is K P in terms of K for the following reation?2 NO(g) + O 2 (g) 2 NO 2 (g) a) K = KRT b) K = K/RT ) K = KR/T d) K = K/(RT) 2 4

5 17. What is the orret equilibrium onstant exression for the reation:ans The equation relating K and K is a) K = b) K = ) K = d) K = K K n (RT) n RT K RT n K (RT) n 19. K will be equal to K if a) n = 1 b) n = 0 ) RT = 0 d) n = -1-3 a) 7.94 x 10 b) ) d) 54.5 o 20. Consider the reversible reation at equilibrium at 392 C: 2A(g) + B(g) C(g) The artial ressures are found to be: A: 6.70 atm, B: 10.1 atm, C: 3.60 atm. Evaluate K for this reation. 5

6 20. Whih of the following will result in an equilibrium shift to the right? PCl (g) + Cl (g) 3 2 PCl (g) DH = 87.9 kj/mol 5 a) Inrease temerature/inrease volume b) Inrease temerature/derease volume ) Derease temerature/inrease volume d) Derease temerature/derease volume 21.Whih aurately reflets the hanges in onentration that will our if O is added to disturb the 2 equilibrium? 2 NO(g) + O (g) 2 NO (g) 2 2 6