Chemistry 12 Provincial Workbook Unit 02: Chemical Equilibrium. Multiple Choice Questions

Transcription

1 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / 63 Chemistry 1 Provincial Workbook Unit 0: Chemical Equilibrium 1. Consider the following... Multiple Choice Questions Which of the following lists these uilibria from the one that most favours products to the one that least favours products? A. I, II, III B. I, III, II C. II, III, I D. III, I, II. Consider the following uilibrium system... A. Increasing CO will increase Ni(s)+4CO(g) NiCO 4 (g), ΔH=- 603kJ Which of the following statements is correct? K. B. Increasing temperature will increase K. C. Increasing temperature will decrease K. D. Decreasing 4 Ni CO will decrease K.

2 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / Consider the uilibrium... N (g)+3h (g) NH 3(g), K =64 A 1.0L container is filled with 0.8 mol N, 0.16 mol H and 0.54 mol NH 3. In which direction will the reaction proceed and what will happen to the pressure of the system? 4. Consider the following uilibrium... A. H O = B. HO = H O = C. K H O = D. NH NO (s) N (g)+h O(g) 4 Which of the following correctly represents the HO at uilibrium? K N 1 K K N N N NH NO 4 NH NO 4 5. Consider the following uilibrium: 4NH 3(g) 5O (g) 4NO(g) 6HO(g) energy Which of the following will cause the uilibrium to shift to the left? A. adding H O(g) B. removing some NO(g) C. increasing the volume D. decreasing the temperature

3 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 3 / Consider the following uilibrium NO(g) O (g) NO (g) energy When the volume of the container is increased, the uilibrium shifts to the A. left and K decreases B. right and K increases C. left and K remains constant D. right and K remains constant 7. Consider the following uilibrium 4HCl(g) O (g) HO(g) Cl (g) energy The temperature of the uilibrium system is increased and a new uilibrium is established. The rates of the forward and reverse reactions for the new uilibrium compared to the original uilibrium have 8. The value of K changes when A. a catalyst is added B. the temperature changes C. the surface area changes D. the concentration of reactants changes

4 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 4 / Consider the following uilibrium PCl 5(g) PCl 3(g) Cl(g) A 1.00 L flask contains mol PCl 5, mol PCl 3 and mol Cl at uilibrium. The value of A B..50 C D K is 10. Consider the following uilibrium N (g) O (g) NO (g) Equal moles of N and O are added, under certain conditions, to a closed container. Which of the following describes the changes in the reverse reaction which occur as the system proceeds toward uilibrium? 11. A chemical uilibrium is described as dynamic because A. maximum randomness has been achieved B. the pressure and temperature do not change C. both reactants and products continue to form D. the concentrations of chemical species remain constant

5 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 5 / Which of the following reactions results in an entropy increase? A. C(s) O (g) CO(g) B. N (g) H (g) NH 4(l) C. SO (g) O (g) SO 3(g) D. Ag (aq) Cl (aq) AgCl(s) 13. Consider the following uilibrium: CH COOH(aq) H O(l) CH COO (aq) H O (aq) heat A stress was applied at time t 1 and the data was plotted on the following graph The stress that was imposed at time t 1 is the result of A. the addition of HCl B. decreasing the temperature C. the addition of NaCH 3COO D. increasing the volume of the container

6 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 6 / Consider the following potential energy diagram for an uilibrium system When the temperature of the system is increased, the uilibrium shifts to the A. left and the K increases B. left and the K decreases C. right and the K increases D. right and the K decreases 15. Consider the following uilibrium O 3(g) 3O (g), K 65 Initially, 0.10 mole of 3 O and 0.10 mole of O are placed in a 1.0 L container. Which of the following describes the changes in concentrations as the reaction proceeds toward uilibrium?

7 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 7 / Which of the following applies to a chemical uilibrium? A. I only B. I and II only C. II and III only D. I, II and III I. Forward and reverse reaction rates are ual II. Equilibrium can be achieved from either direction III. Macroscopic properties are constant 17. In which of the following will the driving forces of minimum enthalpy and maximum entropy oppose one another? A. C(s) O (g) CO(g), H 1kJ B. N (g) O (g) NO(g),ΔH 164kJ C. CO(g) O (g) CO (g),δh 566kJ D. 4CO (g) 6HO(g) CH 6(g) 7O (g), H 31kJ 18. Ammonia, NH 3, is produced by the following reaction N (g) 3H (g) NH 3(g) energy Which of the following would result in the highest concentration of ammonia at uilibrium? A. increasing the temperature and increasing the pressure B. decreasing the temperature and increasing the pressure C. increasing the temperature and decreasing the pressure D. decreasing the temperature and decreasing the pressure 19. Consider the following reaction C(s) H (g) CH 4(g), H 74.8kJ Which of the following will cause an increase in the value of A. increasing H B. decreasing the volume C. finely powdering the C(s) D. decreasing the temperature K?

8 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 8 / Consider the following uilibrium At uilibrium H of K is A. 3.10x10 4 B. 1.99x10 1 C. 5.03x10 3 D. 3.x mol/L H (g) I (g) HI(g), I 1. Consider the following uilibrium 0.000mol/L and HI mol/L. The value NOCl(g) NO(g) Cl (g) A flask of fixed volume is initially filled with NOCl(g), NO(g) and Cl (g). When uilibrium is reached, the pressure has increased. To reach uilibrium, the reaction proceeded to the A. left because Trial K was less than K B. right because Trial K was less than K C. left because Trial K was greater than K D. right because Trial K was greater than K. In which of the following do both minimum enthalpy and maximum entropy factors favour the reactants? A. Cl (g) Cl (aq), H 5kJ B. C(s) HO(l) CO(g) H (g), H 131kJ C. CO (g) 3HO(g) CH5OH(l) 3O (g), H 139kJ D. NaCO 3(s) HCl(aq) NaCl(aq) CO (g) HO(l), H 8kJ

9 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 9 / Consider the following uilibrium H (g) I (g) HI(g) Which graph represents what happens when some HI is removed and a new uilibrium is established? 4. Consider the following uilibrium A. adding a catalyst B. changing volume C. adding an inert gas D. changing temperature CO(g) HO(g) CO (g) H (g), H 41kJ What will cause a shift in the uilibrium?

10 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 10 / The uilibrium expression for a reaction is K H 3 3 Bi HS The reaction could be 6 A. B. C. D. 3 6H (aq) BiS(s) Bi (aq) 3HS(g) 6H (aq) Bi S (s) Bi (aq) 3H S(g) Bi (aq) 3HS(aq) BiS 3(s) 6H (aq) 3 Bi (aq) 3HS(aq) BiS 3(aq) 6H (aq) 6. Consider the following PCl 3(g) Cl (g) PCl 5(g), K 0.45 at 7 C Initially, a 1.00L flask is filled with mol PCl 3, mol Cl, and mol PCl 5 at 7 C. Use Cl as uilibrium is established. K to predict the change in trial

11 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 11 / Consider the following uilibrium reaction: ICI(g) I (g) Cl (g) Some ICI is added to an empty flask. How do the reaction rates change as the system approaches uilibrium? Forward rate Reverse rate A. increases increases B. increases decreases C. decreases increases D. decreases decreases 8. In an uilibrium system, continuing microscopic changes indicate that the uilibrium is A. dynamic B. complete C. exothermic D. spontaneous 9. Consider the following uilibrium A. adding CuO(s) B. removing O (g) C. adding a catalyst D. decreasing the temperature 4CuO(s) energy CuO(s) O (g) The uilibrium will shift to the right as a result of 30. Consider the following uilibrium N (g) 3H (g) NH 3(g) The volume of the system is decreased. The uilibrium shifts A. left since the reverse rate is greater than the forward rate B. left since the forward rate is greater than the reverse rate C. right since the reverse rate is greater than the forward rate D. right since the forward rate is greater than the reverse rate

12 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / Consider the following uilibrium SO 3(g) SO (g) O (g), H 198kJ When the temperature is increased, the uilibrium will shift A. left with K becoming larger B. right with K becoming larger C. left with K becoming smaller D. right with K becoming smaller 3. Starting with ual concentrations of reactants, which of the following will be closest to completion at uilibrium? A. CO(g) Cl (g) COCl (g), K B. PCl (g) Cl (g) PCl (g), K.9x10 C. D. 3 5 CO(g) Cl (g) COCl (g), K 4.5x10 CH O (g) NO (g) CH O NO (g), K.1x Consider the following uilibrium 9 1 COF (g) CO (g) CF 4(g) At uilibrium, a 1.00L container contains x10 mol CF 4. What is the value of K? x10 mol COF, x10 mol CO, and A. 7.07x10 4 B. 1.41x10 3 C D..00

13 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 13 / Consider the following reaction ICI(g) I (g) Cl (g) A closed container is initially filled with ICI(g). What are the changes in the rate of the forward reaction and I, as the system approaches uilibrium? 35. The entropy of a system is a term used to describe A. randomness B. heat content C. average kinetic energy D. stored chemical energy 36. Consider the following uilibrium - Cu (aq) 4Br CuBr 4 (aq) (aq) energy blue colourless green Which of the following will cause this uilibrium to change from blue to green? A. adding NaBr(s) B. adding 3 NaNO (s) C. adding a catalyst D. decreasing the temperature

14 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 14 / Consider the following uilibrium: Ni(s) 4CO(g) Ni(CO) (l), H kJ Which of the following will cause this uilibrium to shift to the left? A. add some CO B. decrease the volume C. remove some Ni(CO) 4 D. increase the temperature 38. Consider the following uilibrium NO 4(g) energy NO (g) Which of the following shows the relationship between concentration and time as a result of adding a catalyst at time t 1?

15 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 15 / Consider the following uilibrium A. K B. K C. K D. K HI HS HS HI HI S S H S I H S I HI HS(g) I (s) HI(g) S(s) What is the uilibrium expression for this reaction? 40. Consider the following uilibrium At uilibrium, the CO uilibrium CO. A mol/L B mol/L C. 0.33mol/L D. 1.0mol/L CO(g) HO(g) CO (g) H (g), K mol/L, H O 0.30mol/L, and H 0.90mol/L. Calculate the

16 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 16 / Consider the following CO CO (g) CF 4(g) COF (g), K 0.50 In a reaction container the initial concentrations are A. left since Trial K < K B. left since Trial K > K C. right since Trial K < K D. right since Trial K > K 0.50mol/L, CF mol/L, COF 0.30mol/L To reach uilibrium, the reaction will proceed 4. All chemical uilibriums must have A. K 1 B. reactants products C. rate forward = rate reverse D. mass of reactants = mass of products 43. Consider the following uilibrium reaction 4HCl(g) O (g) HO(g) Cl (g) 111.4kJ For the forward reaction, how do enthalpy and entropy change? Enthalpy Entropy A. increases decreases B. decreases decreases C. increases increases D. decreases increases

17 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 17 / Consider the following uilibrium CH Cl(aq) OH (aq) CH OH(aq) Cl (aq) 3 3 A. HNO 3 B. KNO 3 C. NaOH D. CH3Cl The uilibrium will shift to the left as a result of the addition of 45. Consider the following uilibrium at 5 C A. 4 K B. K C. K D. K CO 1 CO Ni(CO) 4 CO NI Ni(CO) 4 CO Consider the following uilibrium At uilibrium, CO A mol/L B mol/L C mol/L D. 0.mol/L Ni(s) 4CO(g) Ni(CO) 4(l) For this reaction COF (g) CO (g) CF 4(g), K mol/L and CF mol/L. What is COF at uilibrium?

18 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 18 / Consider the following uilibrium H O(g) Cl O(g) HOCl(g), K Initially, a 1.00L flask is filled with mol of HO, mol of ClO and mol of HOCl. As uilibrium is established, the reaction proceeds to the A. left because Trial K > K B. left because Trial K < K C. right because Trial K > K D. right because Trial K < K 48. What will cause the value of K for an endothermic reaction to increase? A. increasing [products] B. decreasing [products] C. increasing the temperature D. decreasing the temperature 49. Consider the following uilibrium N O (g) NO (g) 4 An uilibrium mixture contains 4.0x10 mol NO4 What is the value of and K? 1.5x10 mol NO in a 1.0 L flask. A. B. C. D. 5.6x x x x Which of the factors below is not a condition necessary for uilibrium? A. a closed system B. a constant temperature C. ual forward and reverse reaction rates D. ual concentrations of reactants and products

19 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 19 / In order for a chemical reaction to go to completion, how must the entropy and enthalpy change? 5. Consider the following uilibrium system SO (g) O (g) SO (g),k 1.x If additional SO is added to the system, what happens to the uilibrium and the value of K? 53. Consider the following uilibrium system N (g) 3H (g) NH 3(g) Determine the changes in reaction rates as a catalyst is added.

20 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 0 / Consider the following uilibrium system A. 3 K B. K C. K D. K O 1 O KClO3 KCl O KCl O KClO 3 3 KClO 3(s) KCl(s) 3O (g) Which of the following is the uilibrium constant expression? Consider the following uilibrium CO (g) HO(g) CH 4(g) O (g) Which of the options below indicates that the reactants are favoured? A. K is zero B. K is very large C. K is slightly less than 1 D. K is slightly greater than Consider the following uilibrium NO 4(g) energy NO (g) How are K and NO affected by the addition of neon (an inert gas) into the container at 4 constant volume.

21 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 1 / Consider the following uilibrium At uilibrium, Cl 1.0M Cl (g) NO(g) NOCl(g), K 5.0 and NO.0M. What is the NOCl at uilibrium? A M B M C. 4.5 M D. 10 M 58. For the uilibrium system below Cu(s) Ag (aq) Ag(s) Cu (aq) We would know the system is at uilibrium because A. Cu Ag B. Cu Ag C. the mass of Cu(s) remains constant D. the mass of the entire system remains constant 59. For the reacting system Li(s) H O(l) LiOH(aq) H (g), H 433kJ? What will entropy and enthalpy factors favour?

22 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. / Consider the following uilibrium N (g) 3H (g) NH 3(g) If some Ne gas is added at a constant volume then how will N, H, and K be affected? 61. What is the effect of adding a catalyst to an uilibrium system? A. The value of E a increases B. The value of K increases C. Forward and reverse rates increase D. The concentration of products increases 6. Consider the following uilibrium CrO (aq) H (aq) Cr O H O(l) 4 7 What is the K expression? A. B. C. D. CrO 4 H CrO 7 CrO 7 CrO 4 H CrO 7 CrO 4 H CrO 7 HO CrO 4 H

23 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 3 / A container is initially filled with pure SO 3. After a period of time, the following uilibrium is established SO (g) O (g) SO (g), K 7.0x A. mostly products B. mostly reactants C. 3 5 reactants and 5 products D. ual amounts of reactants and products 64. Consider the following uilibrium What does this uilibrium mixture contain? CO(g) O (g) CO (g), K 4.0x10 10 What is the value of K for CO (g) CO(g) O (g)? A. B. C. D. 4.0x x x x Consider the following uilibrium A. add H B. add HBr C. increase the pressure D. reduce the temperature H (g) Br (g) HBr(g), H 36kJ How could the value of K be increased?

24 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 4 / A student places some HI (g) into a closed reaction container and the following uilibrium is established... HI(g) I (g)+h (g) Which of the following describes the forward and reverse reaction rates? 67. Consider the uilibrium... H (g)+feo(s) H O(g)+Fe(s) The following chemicals are placed in separate 1.0 L containers. A. Container III only B. Container IV only C. Containers I and II only D. Containers III and IV only In which container(s) will the uilibrium be established?

25 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 5 / Consider the following energy+6co (g)+6h O(l) C H O (s)+6o g Which of the following describes how enthalpy and entropy change in the forward direction? 69. Consider the following system at uilibrium... energy+n H CO (s) NH (g)+co (g) 6 3 Which of the following is correct when the volume of the system is increased? 70. Consider the following system at uilibrium... NO(g)+O (g) NO (g) Some O is added to the uilibrium. Which of the following describes how the forward and reverse reaction rates change as a new uilibrium is being established?

26 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 6 / Consider the following PE diagram A. 1 B. C. 3 D. 4 Identify the activation energy for the forward uncatalyzed reaction. 7. In which of the following will entropy and enthalpy factors favour the establishment of an uilibrium? A. CaCO (s) 178kJ CaO(s) CO (g)? 3? B. Mg(s) HCl(aq) MgCl (aq) H (g) 45kJ C. D.? 4 C(s) H (g) C H (g), H 5.3kJ C H (g) 7O (g) 4CO (g) 6H O(g), H 1560kJ? (A ) Consider the following uilibrium CO(g) H (g) CH3OH(g), H 91kJ Which of the factors below would increase the concentration of CH3OH at uilibrium? A. an addition of CO B. an increase in the volume C. a decrease in the pressure D. an increase in the temperature

27 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 7 / Consider the following uilibrium PCl 3(g) Cl (g) PCl 5(g) If the volume of the system is decreased, how will the reaction rates in the new uilibrium compare with the rates in the original uilibrium? 75. Consider the following uilibrium H (g) I (g) HI(g), H 71.9kJ colourless purple colourless Which of the following would allow you to conclude that the system has reached uilibrium? A. The pressure remains constant. B. The reaction rates become zero. C. The colour intensity remains constant. D. The system shifts completely to the right. 76. Consider the following uilibrium A. K B. K C. K D. K 3 CO CO CO CO 3 CO Fe CO FeO3 3 FeO3CO CO Fe FeO 3(s) 3CO(g) Fe(s) 3CO (g) Identify the uilibrium constant expression.

28 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 8 / Consider the following uilibrium system NO(g) Cl (g) NOCl(g), H 77kJ In which direction will the uilibrium shift and what happens to the value of temperature of the system is increased? K when the 78. Consider the following uilibrium At uilibrium it was found that CO CH OH 3 A. 9.94x10 B C..51 D CO(g) H (g) CH3OH(g) mol/l, H 0.50 mol/l and mol/l. Which of the following is the uilibrium constant value? 79. In a certain reaction H 136kJ and Ea reverse reaction? A. The reverse reaction is exothermic and Ea B. The reverse reaction is exothermic and Ea C. The reverse reaction is endothermic and Ea D. The reverse reaction is endothermic and Ea 40J 40kJ 96kJ. Which of the following is true of its 96kJ 3kJ

29 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 9 / Two experiments were performed involving the following uilibrium. The temperature was the same in both experiments. H (g) I (g) HI(g) In experiment A, 1.0 M H and 1.0 M I were initially added to a flask and uilibrium was established. In experiment B,.0 M HI was initially added to a second flask and uilibrium was established. Which of the following statements is always true about the uilibrium concentrations? A. B. C. HI in experiment A HI uals H in experiment A HI in experiment A uals HI in experiment B H uals D. HI in experiment A uals 1 I in experiment B 81. Which of the following reactions is accompanied by an increase in enthalpy? A. NO(g) O (g) NO (g) 113kJ B. H (g) O (g) 484kJ HO(g) C. SO3 SO (g) O (g), H 197kJ D. 4HCl(g) O (g) HO(g) Cl(g), H 111.4kJ 8. Two substances are mixed and no reaction occurs. With respect to enthalpy and entropy, which of the following could explain why no reaction occurs?

30 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 30 / Consider the following reaction N (g) 3H (g) NH 3(g) Which of the following diagrams represents what happens to the forward and reverse reaction rates when the catalyst Fe3O 4 is added? 84. Temperature is gradually decreased then held constant in an exothermic uilibrium. Which of the following represents the change in the reverse reaction rate?

31 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 31 / If NO 4is placed in a flask at a constant temperature, which of the following is true as the system approaches uilibrium? A. The colour gets darker as NO increases B. The colour gets lighter as NO decreases NO 4(g) NO (g) colourless brown C. The colour gets darker as NO 4 increases D. The colour gets lighter as NO 4 decreases 86. The system above reaches uilibrium. Considering enthalpy and entropy factors, which of the following is true with respect to the forward reaction? NO 4(g) NO (g) colourless brown A. The entropy is increasing and the reaction is exothermic B. The entropy is decreasing and the reaction is exothermic C. The entropy is increasing and the reaction is endothermic D. The entropy is decreasing and the reaction is endothermic 87. In which of the following reactions do the tendencies for minimum enthalpy and maximum entropy both favour reactants? A. 3O (g) O (g), H 85kJ? 3? B. N (g) 3H (g) NH (g), H 9kJ C. D. 3? BrCl(g) Br (g) Cl (g), H 9.3kJ CaCO (s) CaO(s) CO (g), H 175kJ? 3

32 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 3 / Consider the following uilibrium CaCO 3(s) CaO(s) CO (g), H 175kJ Which of the following diagrams best represents the change in the concentration of CO as temperature is decreased at time t 1? 89. The Haber Process is used to produce ammonia commercially according to the following uilibrium N (g) 3H (g) NH 3(g) energy Which of the following conditions will produce the highest yield of ammonia? A. increase temperature and increase pressure B. increase temperature and decrease pressure C. decrease temperature and increase pressure D. decrease temperature and decrease pressure

33 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 33 / Consider the following uilibrium Cr O (aq) OH (aq) CrO (aq) H O(l), K The concentration of ions at uilibrium was measured at a specific temperature and found to be CrO M and OH 0.00M. What is the uilibrium CrO 4 4 A. 1.7x10 M 3 B. 3.1x10 M C. 1.3x10 M 1 D..0x10 M 91. In which of the following uilibria does the concentration of reactants ual the concentration of products? A. NO 4(g) NO (g), K 0.71 B. H (aq) OH (aq) H O(l), K 1.0x10 C. CO (g) H (g) CO(g) H O(g), K 0.79 D. SnO (s) H (g) Sn(s) HO(g),K Consider the following uilibrium 14 C(s) HO(g) CO(g) H (g) At uilibrium 4.0x10 mol CO, 1.0x10 mol H O,and 1.0x10 mol C 1.0 L container. What is the value of K? were present in a A B C. 6.3 D. 16

34 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 34 / Consider the following uilibrium COF (g) CO (g) CF 4(g) Initially, 0.1 M CO and 0.0 M CF 4 are placed in a container. At uilibrium, it is found that the COF is M. What is the value of K? A B C. 8 0 D Which of the following represents the value for the activation energy of the forward reaction in an uilibrium system? A. Ea(forward) Ea(reverse) H B. Ea(forward) Ea(reverse) H C. Ea(forward) ΔH Ea(reverse) D. E ΔH E a(forward) a(reverse) 95. Consider the following uilibrium CaCO 3(s) CaO(s) CO (g) In which of the flasks will this uilibrium be established? A. 1,, 3 only B. 1,, 4 only C. 1, 3, 4 only D. 3, 4 only

35 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 35 / Which of the following forward reactions demonstrates decreasing enthalpy and increasing entropy? 1? A. Hg(l) O (g) HgO(s), H 91kJ? B. HCl(g) H (g) Cl (g), H 185kJ C. D.? HgO(s) Hg(l) O (g), H 18kJ SO (g) SO (g) O (g), H 00kJ? Which of the following would cause the amount of NH 3 at uilibrium to increase? A. an increase in O B. a decrease in volume C. a decrease in temperature D. an increase in temperature 4NH 3(g) 3O (g) N (g) 6HO(l), H 1530kJ 98. What happens when O is added to the above system? 4NH 3(g) 3O (g) N (g) 6HO(l), H 1530kJ

36 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 36 / If some O is injected into the system, what happens to the forward and reverse reaction rates during the shift to re-establish uilibrium? 4NH 3(g) 3O (g) N (g) 6HO(l), H 1530kJ 100. Consider the uilibrium expression K (01) for reaction 01 SO (g) 1 O (g) SO 3(g) and the uilibrium expression SO 3(g) O (g) SO (g) How is K (0) for reaction 0 K (01) related to K (0)? K K A. (01) (0) B. K K (0) C. (0) D. K (0) K K K (01) 1 (01) 1 (01)

37 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 37 / Consider the following uilibrium: Written Questions H (g) I (g) HI(g), K 49 A 1.00 L container is initially filled with moles of HI. Calculate the concentration of HI at uilibrium. ( marks). Consider the following diagram for a chemical system containing three substances represented by A, B and C: A. What feature of the graph indicates that the system reaches uilibrium? (1 mark) B. Write a balanced uation for the uilibrium reaction. ( marks) C. Calculate K at uilibrium. ( marks)

38 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 38 / Describe how enthalpy and entropy change, in the forward direction, as an exothermic reaction reaches uilibrium. Explain your reasoning. ( marks) 4. Consider the graph below representing the following uilibrium... CH CH CH CH (g) CH CH(CH ) (g) n butane isobutane Data for the graph was obtained from various uilibrium mixtures. Calculate the value of K for the uilibrium. ( marks)

39 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 39 / Consider the following uilibrium system... N (g) 3H (g) NH 3(g) energy A 1.00 L container is filled with 5.0 mol NH 3 and the system proceeds to uilibrium as indicated by the graph. A. Draw and label the graph for N and H. ( marks) B. Calculate the K for N (g) 3H (g) NH 3(g) energy ( marks) 6. State Le Chatelier s Principle. ( marks) 7. Consider the following uilibrium... 4HCl(g) O (g) HO(g) Cl (g) energy A. How does the entropy change in the forward direction? Explain your reasoning. (1 mark)

40 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 40 / 63 B. How does the enthalpy change in the forward direction? Explain your reasoning. (1 mark) 8. Consider the following uilibrium... H (g) I (g) HI(g), K 1.x10 A.0 L flask is filled with 0.10 mol HI. Calculate the concentration of H at uilibrium. (3 marks) 9. Consider the following uilibrium... 3 Fe (aq) SCN (aq) FeSCN (aq) 3 Initially, 50.0mL of 0.10M Fe SCN. At uilibrium, the concentration of FeSCN is found to be 0.050M. Calculate the K for the reaction. (4 marks) 10. Methanol, CH3OH, is produced industrially by the following reaction... CO(g) H (g) CH3OH(g) heat A. State two different methods of shifting the uilibrium to the right. (1 mark) B. In terms of rates, explain why these methods cause the uilibrium to shift to the right. (1 mark)

41 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 41 / Consider the following uilibrium... H (g) I (g) HI(g) A.0L container is filled with mol of H and mol of I. Equilibrium is reached after 15.0 minutes at which time there is mol of HI present. Sketch and label the graphs for the changes in concentrations of H, I and HI for the time period of 0 to 30.0 minutes. (3 marks)

42 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 4 / Consider the observations for the following uilibrium... N O (g) NO (g) 4 colourless brown A. Sketch the potential energy curve on the graph below for this uilibrium. (1 mark) B. Explain the colour change using Le Chatelier s Principle. (1 mark) C. Other than changing temperature, what could be done to cause a shift to the left? (1 mark)

43 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 43 / Consider the data obtained for the following uilibrium... 3 Fe (aq) SCN (aq) FeSCN (aq) A. Calculate the FeSCN in experiment #. (3 marks) 14. Consider the following reaction 3 Fe (aq) SCN (aq) FeSCN (aq) yellow colourless red When a few drops of 6.0 M NaOH is added to 5.0 ml of the above system, a precipitate of FeOH 3 forms and the solution turns pale yellow. A. Explain this colour change in terms of Le Chatelier s Principle. ( marks) B. Describe the effect on the rate of the reverse reaction as the color change occurs. (1 mark) 15. Consider the following uilibrium: Initially, 1.00x10 mol of I and uilibrium, IF is 3I (g) 3F (g) IF (g) I4F (g) x10 mol 3.00x10 M of F and put into a 10.00L flask. At. Calculate the K. (4 marks)

44 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 44 / Consider the following uilibrium system: COF (g) CO (g) CF 4(g), K.00 A.00 L container is filled with mol of COF. Calculate the COF at uilibrium. (5 marks) 17. Consider the following uilibrium system: - Cu (aq) 4Br (aq) CuBr 4 (aq) blue colourless green Cooling the uilibrium changes the colour from green to blue. What effect will the decrease in temperature have on K? Explain, using Le Chatelier s Principle. ( marks) 18. A flask is initially filled with some HI. At uilibrium, the HI H at uilibrium? (3 marks) HI(g) H (g) I (g), K mol/L. What is the 19. Consider the following uilibrium system: NOCl(g) NO(g) Cl (g),k 1.6x10 5 A 1.00 L flask is filled with 0.0 mol NOCl, 0.10 mol NO and 0.10 mol Cl. State and show by calculation the direction in which the reaction proceeds to reach uilibrium. (4 marks)

45 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 45 / Write four statements that apply to all chemical uilibrium systems. ( marks) 1. Consider the following uilibrium system H (g) Br (g) HBr(g), K 14.8 A closed container was initially filled with ual moles of H and Br. When uilibrium is reached, the HBr is 0.39 mol/l. What was the initial H? (4 marks). Consider the following graph for the reaction H (g) I (g) HI(g) A. The temperature is increased at t 1 and uilibrium is re-established at t. On the above graph, sketch the line representing the HI between time t 1 and t 3. (1 mark) b. Calculate the value of K after t. ( marks)

46 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 46 / Consider the following uilibrium system SO (g) O (g) SO 3(g) A 1.00 L container is initially filled with mol SO, mol O. At uilibrium the O concentration is mol/l. Calculate the value of K. (4 marks) 4. Consider the following uilibrium... NF (g) N F (g) Equilibrium shifts to the right when the volume is decreased. Describe the changes in reaction rates that cause this shift to the right. ( marks) 5. Consider the following... Initially, 0.00 mol of H and o.00 mol of I are added to an empty.00 L container. At uilibrium, the I is 0.00 mol/l. What is the value of K? (4 marks) 6. State Le Chatelier s Principle. ( marks) 7. Consider the following... CH (g)+h O(g) CO(g)+3H (g) 4 Initially, mol HO, 0.80 mol CO and mol H are placed into a 4.00 L container. At uilibrium, the H is 0.00 mol/l. What is the value of K? (4 marks)

47 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 47 / Given the reacting system... H (g)+i (g) HI(g), K =64 Equal moles of H, I and HI are placed in a 1.0 L container. Use calculations to determine the direction the reaction will proceed in order to reach uilibrium. (3 marks) 9. Consider the following uilibrium system... H (g)+i (g) HI(g) The system is said to shift right as a result of the addition of extra H (g). Describe the suence of changes in both forward and reverse reaction rates as the system goes from the original uilibrium to the new uilibrium. (3 marks) 30. Consider the following uilibrium system... NO(g)+Cl (g) NOCl(g), K =8.5 A closed flask is found to contain 0.40 M NO(g), 0.3 M Cl (g) and 5.6 M NOCl(g). Use appropriate calculations to determine the direction the reaction proceeds to reach uilibrium. (3 marks)

48 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 48 / 63 Multiple Choice Questions Answer Key 1 D 1 B 41 C 61 C 81 C C C 4 C 6 B 8 B 3 B 3 B 43 B 63 A 83 A 4 A 4 D 44 A 64 D 84 B 5 A 5 C 45 B 65 D 85 A 6 C 6 A 46 B 66 A 86 C 7 A 7 C 47 A 67 D 87 A 8 B 8 A 48 C 68 A 88 A 9 A 9 B 49 A 69 C 89 C 10 A 30 D 50 D 70 C 90 C 11 C 31 B 51 B 71 B 91 D 1 A 3 A 5 C 7 A 9 B 13 C 33 D 53 A 73 A 93 D 14 B 34 A 54 A 74 A 94 A 15 B 35 A 55 C 75 C 95 C 16 D 36 A 56 A 76 A 96 D 17 C 37 D 57 C 77 D 97 D 18 B 38 C 58 C 78 B 98 C 19 D 39 A 59 B 79 D 99 D 0 C 40 C 60 D 80 C 100 D

49 R. Janssen, MSEC Chemistry 1 Provincial Workbook (Unit 0), P. 49 / 63 Written Questions Answer Key 1..

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