1arcuricacid.weebly.com/uploads/2/3/1/0/23106948/ch12unit... · Web viewUnit 1 Provincial Practice Questions – Multiple Choice 1. As an activated complex changes into products,

Chemistry 12 Unit 1 Provincial Practice

Chemistry 12Unit 1 Provincial Practice Questions – Multiple Choice1. As an activated complex changes into products, what changes occur in the chemical

bonds of the activated complex and the PE of the system?

Bonds PEA. form increasesB. form decreasesC. break increasesD. break decreases

2. An activated complex can be described asA. a particle of maximum KE and minimum PE.B. a stable particle found in a reaction mechanism.C. an unstable particle that is neither reactant nor product.D. a particle which is first used then regenerated in a reaction mechanism.

3. When a catalyst is added to a reaction

I. the enthalpy change of reaction increasesII. a new mechanism is providedIII. the activation energies for forward and reverse reactions are decreasedA. II onlyB. I and II onlyC. II and III onlyD. I, II and III

4. A catalyst changes the rate of a reaction by ...A. changing H.B. increasing the temperature.C. decreasing the energy of the products.D. providing an alternate reaction mechanism.E. increasing the number of collisions.

5. Which of the following changes will increase the average kinetic energy of reactant molecules?A. adding a catalystB. increasing the temperatureC. increasing the surface areaD. increasing the concentration

6. Collision theory states that...A. all collisions lead to chemical reactions. B. most collisions lead to chemical

reactions.C. very few reactions involve particle

collisions.D. effective collisions lead to chemical

reactions.E. reactions do not require particles to

collide.

Unit 1 Provincial Practice 9/11/2023 Page 1


7. Which of the following are necessary for successful collisions to occur? I. Favourable collision geometry II. Sufficient kinetic energy III. Large H

A. I onlyB. I and II onlyC. II and III onlyD. I and III onlyE. I, II, and III

8. When a collision occurs between two reactant species which possess between them the

minimum kinetic energy, called activation energy, a product does not always form. This

may be a result of....A. low temperature. B. small surface area. C. low concentrations.D. unfavourable geometry. E. a lack of a catalyst. F.

9. Which of the following would result in a successful collision between reactant particles?

A. particles have sufficient KEB. particles convert all their PE into KEC. particles are in an excited state and are catalyzedD. particles have sufficient KE and proper molecular orientation

10. What happens to the activation energy as the temperature in a reacting system increases?

A. the activation energy increasesB. the activation energy decreasesC. the activation energy stays the sameD. the activation energy is converted to kinetic energy

11. Which of the following potential energy curves represents a catalyzed endothermic reaction in the forward direction?

A. IB. IIC. IIID. IVUnit 1 Provincial Practice 9/11/2023 Page 2


12. Activation energy is described asA. the energy of the activated complex.B. a point on the PE diagram where KE = PE.C. the unstable high PE structural arrangement of atoms.D. the minimum PE difference between the activated complex and the reactants.

13. Consider the following PE diagram:

What are the values of H and activation energy (Ea) for the forward reaction? H (kJ) Ea (kJ)

A. -50 100B. -50 200C. +50 100D. +50 200

14. Consider the following PE diagram for a catalyzed and uncatalyzed reaction:

Which of the following describes the reverse reaction? Reaction Activation Energy (kJ) H(kJ)A. Catalyzed 300 -100B. Uncatalyzed 300 -100C. Catalyzed 400 +100D. Uncatalyzed 400 +100


Chemistry 12 Unit 1 Provincial Practice15. When a match is touched to the wick of a candle, the candle begins to burn.

When the match is removed, the candle continues to burn. In this reaction, the match.....A. behaves as a catalystB. supplies the activation energy.C. is part of the rate determining step.D. lowers the activation energy barrier.E. lowers the H of the reaction.

16. Consider the following reaction: 1/2 H2(g) + 1/2 I2(g) --> HI(g) H = +28 kJ

The activation energy for the formation of HI is 167 kJ. The activation energy for thedecomposition of HI is .....A. 28 kJ B. 139 kJ C. 153 kJ D. 167 kJ E. 195 kJ


Which of the following describes this reaction? H ACTIVATION (kJ ) ENERGY (kJ) REACTIONA. -20 40 catalyzedB. -20 60 catalyzedC. -20 60 uncatalyzedD. +20 40 uncatalyzed E. +20 60 uncatalyzed

18. In general, a chemical reaction requiring a large activation energy will proceed ...A. at a fast rate.B. at a slow rate.C. only at low temperatures.D. only at low concentrations.Unit 1 Provincial Practice 9/11/2023 Page 4

Chemistry 12 Unit 1 Provincial PracticeE. only in the presence of a catalyst.


Identify the activation energy for the forward uncatalysed reaction.A. 1 B. 2 C. 3 D. 4 E. 5


Identify the activation energy for the forward catalysed reaction.A. 1 B. 2 C. 3 D. 4 E. 5


Identify the activation energy for the reverse uncatalysed reaction.A. 1 B. 2 C. 3 D. 4 E. 5



5

5

5

5


Identify the activation energy for the reverse catalysed reaction.A. 1 B. 2 C. 3 D. 4 E. 5


Identify the H for the forward uncatalysed reaction.A. 1 B. 2 C. 3 D. 4 E. 5


Identify the H for the forward catalysed reaction.

A. 1 B. 2 C. 3 D. 4 E. 5


Identify the H for the reverse catalysed reaction.


5

5

5

Chemistry 12 Unit 1 Provincial PracticeA. 1 B. 2 C. 3 D. 4 E. 5


Identify the H for the reverse uncatalysed reaction.

A. 1 B. 2 C. 3 D. 4 E. 5

28. Which of the following reactions is endothermic?A. CH4(g) + 2O2(g) CO2(g) + 2H2O(l) + 890.3 kJB. 2N2O2(s) + 2H2O(l) -287.0 kJ 4NaOH(aq) + O2(g)C. CaO(s) + H2O(l) Ca(OH)2(aq) H = -65.2 kJD. CaO(s) + 3C(s) CaC2(s) + CO(g) H = +464.8 kJ

29. Consider the following: 1/2 N2(g) + 1/2 O2(g) NO(g) H = +90 kJ/mol NO

The correct equation including the heat term isA. N2(g) + O2(g) + 90kJ --> 2NO(g) B. N2(g) + O2(g) + 180kJ --> 2NO(g)C. N2(g) + O2(g) --> 2NO(g) + 90kJ D. N2(g) + O2(g) --> 2NO(g) + 180kJ

30. The following diagram shows reactant molecules approaching one another:

What is happening to the kinetic energy and the potential energy? Kinetic Energy Potential Energy

A. Decreasing Decreasing


27. Consider the following information for a reversible chemical reaction:

Which of the following describes the reaction type and enthalpy change for the forward reaction?

Reaction Type Enthalpy Change A. Exothermic -10 kJB. Exothermic +10 kJC. Endothermic -10 kJD. Endothermic +10 kJ

5

1 Forward activation energy = 20 kJ2 Reverse activation energy = 30 kJ

Chemistry 12 Unit 1 Provincial PracticeB. Decreasing IncreasingC. Increasing IncreasingD. Increasing Decreasing

31. What happens to the PE and KE of the reactant particles as the activated complex is

formed?Kinetic Energy Potential Energy

A. Increases DecreasesB. Increases IncreasesC. Decreases DecreasesD. Decreases Increases

32. Which of the following will decrease the fraction of effective collisions during a chemical reaction?

A. Adding a catalyst.B. Increasing the surface area.C. Decreasing the temperature.D. Decreasing reactant concentrations.E. Decreasing surface area.

33. How do KE and PE change as reactant particles collide with each other? KE PE

A. increases; increasesB. increases; decreasesC. decreases; increasesD. decreases; decreases

34. Consider the following mechanism for a reaction:Step 1 HBr + O2 --> HOOBrStep 2 HBr + HOOBr --> 2HOBrStep 3 2HBr + 2HOBr --> 2H2O + 2Br2

Which of the following statements is correct?A. Br 2 is a reactant.B. HBr is a product.C. HOBr is a catalyst.D. HOOBr is a reaction intermediate.

35. A proposed mechanism for a reaction is:Step 1 H3O+ + I- --> HI + H2OStep 2 H2O2 + HI --> H2O + HOIStep 3 HOI + H3O+ --> I- + 2H2O + I2Unit 1 Provincial Practice 9/11/2023 Page 8

Chemistry 12 Unit 1 Provincial PracticeStep 4 I2 + I- --> I3

-

In the above mechanism, which of the following is true for the overall reaction?A. HI is a catalystB. H3O+ is a productC. H2O2 is a reactantD. H2O is an intermediate

36. A substance that is produced in one step in a reaction mechanism and consumed in a

subsequent step, without appearing in the overall reaction, is a(n)A. catalyst.B. product.C. reactant.D. intermediate.

37. Consider the following reaction mechanism: Step1 2NO2 --> NO3 + NOStep 2 NO3 + CO --> NO2 + CO2 Identify a product in the overall reaction.A. COB. CO2C. NO2D. NO3

38. Consider the following reaction mechanism: Step1 2NO2 --> NO3 + NOStep 2 NO3 + CO --> NO2 + CO2 Identify a reactant in the overall reaction.A. COB. CO2C. NOD. NO3

39. Consider the following reaction mechanism: Step 1 NO(g) + O3(g) --> NO2(g) + O2(g)Step 2 O(g) + NO2(g) --> NO(g) + O2(g)

The catalyst is ....A. O B. O2 C. O3 D. NO2 E. NO

40. Consider the following reaction mechanism: Step 1 NO(g) + O3(g) --> NO2(g) + O2(g)Step 2 O(g) + NO2(g) --> NO(g) + O2(g)

A reaction intermediate is:A. O B. O2 C. O3 D. NO2 E. NO Unit 1 Provincial Practice 9/11/2023 Page 9


41. Consider the following reaction mechanism: Step 1: M + X --> MXStep 2: MX + A --> D + X

The chemical species MX is a(n)A. catalystB. inhibitorC. final productD. reaction intermediateE. reactant

42. Consider the following reaction mechanism: Step 1: ICl + H --> HI + HCl (slow)Step 2: ICl + HI --> HCl + I2 (fast)

The species HCl is a.....A. product B. catalyst C. reactantD. reaction intermediate E. activated complex.

43. Consider the following reaction mechanism:Step 1: NO2 + NO2 --> NO + NO3Step 2: NO3 + CO --> NO2 + CO2

The overall reaction is....A. 2NO2--> NO3 + NOB. NO2 + CO --> NO + CO2C. NO3 + CO --> NO2 + CO2D. NO2 + NO3 + CO --> NO3 + NO2 + NO + CO2

44. Consider the following potential energy diagram:

The above potential energy diagram represents an....A. exothermic reaction involving one step.B. exothermic reaction involving two steps.C. endothermic reaction involving one step.D. endothermic reaction involving two steps.E. endothermic and exothermic reaction involving two steps.

45. Consider the following two-step reaction mechanism:


Chemistry 12 Unit 1 Provincial PracticeStep 1: NO2(g) + NO2(g) --> NO(g) + NO3(g) slowStep 2: NO3(g) + CO(g) --> CO2(g) + NO2(g) fast

Which of the following changes would result in the greatest increase in reaction rate?A. increase [CO]B. decrease [NO2]C. decrease [NO3]D. increase [NO3]E. increase [NO2]

46. A certain reaction is able to proceed by various mechanisms. Each mechanism has a different Ea and results in a different overall rate. Which of the following best describes the relationship between the Ea values and the rates?

A. B.

C. D.

47. Consider the following reaction mechanism: Step 1 O3 --> O2 + O Step 2 O3 + O --> 2O2

Which of the following could represent the activated complex for Step 2?A. OB. O2C. O3D. O4

48. A reaction has the following mechanism: Step 1 2NO --> N2O2Step 2 N2O2 + H2 --> N2O + H2O Step 3 N2O + H2 --> N2 + H2O

Which of the following substances is a reactant?A. N2O2B. NOC. H2O


Chemistry 12 Unit 1 Provincial PracticeD. N2O

49. Consider the reaction:C5H12(g) + 8O2(g) --> 5CO2(g) + 6H2O(g)

Which of the following explains, in terms of collision theory, why this reaction occurs in more

than one step?A. a low C5H5(g) concentrationB. low temperature of reactant mixtureC. low probability of a multi-particle collisionD. particles collide with insufficient kinetic energy 50. Consider the following potential energy diagram for a reversible reaction:

Which of the following descriptions is correct?Reaction Activation Energy(kJ) H(kJ)

A. Reverse 10 -20B. Reverse 10 -30C. Forward 30 +10D. Forward 20 +30


What is the minimum potential energy required to change reactants to the activated complex?A. 200 kJB. 300 kJC. 400 kJD. 500 kJ



52.

Select the true statement concerning the above potential energy diagram.A. The catalyzed reaction has a larger H.B. The uncatalyzed reaction has a larger H.C. The catalyzed reaction has a greater rate of reaction.D. The uncatalyzed reaction has a greater rate of reaction.E. The catalyzed reaction has a higher reaction time.

53. As reactant molecules approach each otherA. heat is released.B. a reaction intermediate forms.C. kinetic energy changes to potential energy.D. potential energy changes to kinetic energy.

54. The changes in PE and KE, as reactant molecules approach each other, can be represented by

A. B.

C. D.



55. Which of the following best describes activation energy?A. PE of activated complexB. (PE of products ) - (PE of reactants)C. (PE of reactants) - (PE of activated complex )D. (PE of activated complex ) - (PE of reactants)

56. Consider the following reaction: O(g)+ O3(g) --> 2O2(g) Which of the following describes how the reaction's catalyzed PE diagram compares to

the reaction's uncatalyzed PE diagram?

Ea HA. Ea(catalyzed) < Ea unchangedB. Ea(catalyzed) > Ea unchangedC. Ea(catalyzed) < Ea H(catalyzed) <

D. Unchanged H(catalyzed) < H

57. Which of the following is most likely to have the greatest reaction rate at room temperature?A. 2H2(g) + O2(g) 2H2O(l)B. 2Ag+

(aq) + CrO42-

(aq) Ag2CrO4(s)C. Pb(s) + 2HCl(aq) PbCl2 + H2D. CH4(g) + 2O2(g) CO2(g) + 2H2O(g)

58. Consider the following reaction involving 1.0 g of powdered zinc: Zn(s) + 2HCl(aq) --> H2(g) + ZnCl2(a

Trial Temperature (

oC)

Concentration of HCl

1 60 6.02 30 6.03 30 3.0

The rates, in order of fastest to slowest, areA. 1, 2, 3B. 2, 1, 3C. 3, 1, 2D. 3, 2, 1

59. Increasing the temperature of a reaction increases the reaction rate by I. increasing frequency of collisions Unit 1 Provincial Practice 9/11/2023 Page 14

Chemistry 12 Unit 1 Provincial Practice II. increasing the kinetic energy of collision III. decreasing the potential energy of collisionA. I only.B. I and II only.C. II and III only.D. I, II and III.

60. Consider the graph for the following reaction: The average rate of reaction is slowest in the time interval

A. 0 - 1 minute.B. 0 - 2 minutes.C. 0 - 3 minutes.D. 0 - 4 minutes.

61. Consider the following reaction: N2(g) + 3H2(g) --> 2NH3(g)

If the rate of formation of NH3 is 4.0 x 10-4 mol/s, then the rate of consumption of H2 isA. 2.0 x 10-4 mol/sB. 2.0 x 10-4 mol/sC. 6.0 x 10-4 mol/sD. 1.2 x 10-3 mol/s

62. Which of the following units could be used to express reaction rate?A. mL / sB. mL / gC. g / mLD. mL / mol

63. Which of the following reactions occurs most rapidly at standard conditions?A. 2Sn(s) + O2(g) 2SnO(s)B. CaO(s) + 3C(s) CaC2(s) + CO(g)C. SnO2(s) + 2CO(g) Sn(s) + 2CO2(g)


Chemistry 12 Unit 1 Provincial PracticeD. 2AgNO3(aq) + K2CrO4(aq) Ag2CrO4(s) + 2KNO3(aq)

64. Consider the following reaction: CaO(s) + 2HCl(aq) --> CaCl2(aq) + H2O(l)

Which of the following could be used to measure the rate of this reaction? I. change in pH

II. change in volumeIII. change in pressureIV. change in total mass

A. I onlyB. I and II onlyC. I, III and IV onlyD. II, III and IV only

65. Consider the following reaction: COCl2(g) --> CO(g) + Cl2(g)

Which of the following could be used to determine reaction rate in a closed system?A. a decrease in gas pressureB. an increase in gas pressureC. a decrease in the mass of the systemD. an increase in the mass of the system

66. Which factor explains why potassium generally reacts faster than sodium?A. surface areaB. temperatureC. concentrationD. nature of reactants 67. Which of the following has the lowest rate of reaction?A. Pb(s) + CuCl(aq) Cu(s) + PbCl2(aq)B. HCl(aq) + NaOH(aq) H2O(l) + NaCl(aq)C. H2SO4(aq) + BaSO4(aq) 2H2O(l) + BaSO4(s)D. Pb(NO3)2(aq) + 2NaI(aq) PbI2(s) + 2NaNO3(aq)

68. Consider the following reaction: Zn(s) + 2HC1(aq) --> ZnC12(aq) + H2(g)

Solid zinc was added to 1.0 M HC1. In 20.0 s, the temperature of the container increased

by 0.5°C and 25.00 mL of H2 was produced. The rate of this reaction wasA. 0.5°C/s B. 1. 0 M HC1/s C. 1. 25 mL H2/s D. 0. 050 mol HC1/s

69. Consider the reaction: Ca(s) + 2H2O(l) --> Ca(OH)2(aq ) + H2(g)

At a certain temperature, 2.50 g Ca reacts completely in 30.0 seconds. The rate of consumption of Ca is ....A. 0.00208 mol/min


Chemistry 12 Unit 1 Provincial PracticeB. 0.0833 mol/minC. 0.125 mol/minD. 0.0417 mol/minE. 5.00 mol/min

70. Consider the following reaction: 2 NO2(g) --> 2 NO(g) + O2(g)

Under certain conditions, the rate of decomposition of NO2 is 3.2 x 10–3 mol/s. The rate of

formation of O2 is ..... A. 1.6 x 10–3 mol/sB. 3.2 x 10–3 mol/sC. 4.8 x 10–3 mol/sD. 6.4 x 10–3 mol/sE. 9.6 x 10–3 mol/s

71. Consider the following reaction: CH4(g) + 2O2(g) --> CO2(g) + 2H2O(g)

At a certain temperature, 1.0 mol CH4 is consumed in 4.0 minutes. The rate of production of H2O is ...A. 0.25 mol/minB. 0.50 mol/minC. 2.0 mol/minD. 4.0 mol/min

72. The rate of a chemical reaction is equal to the slope of a graph with the axes labelled

x-axis y-axisA. time rateB. mass timeC. volume of gas timeD. time concentrationE. rate time

73. The addition of a catalyst to a reaction provides an alternate mechanism with....A. higher activation energy and lower reaction rate.B. higher activation energy and higher reaction rate.C. lower activation energy and lower reaction rate.D. lower activation energy and higher reaction time.E. lower activation energy and higher reaction rate.

74. When a catalyst is added to a reaction, H will...A. increase slowly B. remain constantC. decrease slowly D. increase rapidly due to the alternate Unit 1 Provincial Practice 9/11/2023 Page 17

Chemistry 12 Unit 1 Provincial Practicepathway,

E. decrease rapidly due to the alternate pathway.

75. Milk is refrigerated in order to slow the rate of decomposition by bacterial action.The decrease in reaction rate is due toA. a decrease in surface area.B. a decrease in H for the reaction.C. a decrease in the number of molecules present in the container.D. the introduction of an alternate pathway with greater activation energy.E. a decrease in the fraction of particles possessing sufficient energy.

76. The slowest of the following reactions is ....A. Ag+

(aq) + Cl–(aq) AgCl(s)

B. H3O+(aq) + OH–

(aq) 2H2O(l)

C. 3Ba2+(aq)

+ 2PO43–

(aq) Ba3(PO4)2(s)

D. Cu(s) + 2Ag+(aq) Cu2+

(aq) + 2Ag(s)

E. Pb2+(aq) + 2Cl–(aq) PbCl2(s)

77. Which combination of factors will affect the rate of the following reaction? Zn(s) + 2 HCl(aq) --> ZnCl2(aq) + H2(g)

A. temperature and surface area onlyB. temperature and concentration onlyC. concentration and surface area onlyD. temperature, concentration and surface areaE. concentration only

78. In general, reaction rates double when the temperature is increased by 10°C. The temperature of a reaction is increased by 30°C. The rate of the reaction will

increase by a factor of...A. 2B. 4C. 6D. 8E. 16

79. Consider the following reaction at constant temperature in an open system:MgCO3(s) + 2 HCl(aq) --> CO2(g) + H2O(l) + MgCl2(aq)

Which of the following properties could be used to determine the reaction rate?A. mass of the systemB. pressure of the gasC. concentration of H2OD. concentration of MgCO3

80. Consider the following reaction: NaOH(aq) + HCl(aq) --> H2O(l) + NaCl(aq)

The rate of this reaction could be determined by monitoring the change in concentration of

A. H+


Chemistry 12 Unit 1 Provincial PracticeB. Cl–C. Na+D. H2O

81. Consider the following reaction: Zn(s) + 2 HCl(aq) --> H2(g) + ZnCl2(aq)

Data collected for the above reaction are summarized in the table below:

The rate of this reaction can be measured in units of......A. g/min B. g/mL C. min/mL D. g/ml°C E. º C/g

82. Consider the reaction:

2C20H42(s) + 61O2(g) 40CO2(g) + 42H2O(g)

If the rate of production of H2O is 0.98 g/min, what is the rate of oxygen consumption? A. 1.42 g/minB. 2.5 g/sC. 0.079 g/minD. 150 g/sE. 0.042 g/s

83. Which of the following reactions is most likely to proceed at the greatest rate under

standard conditions?A. Zn(s) + S(s) ZnS(s)B. H2(g) + I2(g) 2HI(g)C. Cu(s) + Cl2(g) CuCl2(s)D. 2KOH(aq) + H2SO4(aq) 2H2O(l) + K2SO4(aq)

84. Given the following graph:


Curve 1

Curve 2


Which one of the following statements are true?A. Curve 1 is at a higher temperature than curve 2 and a lower fraction of the colliding particles possess sufficient kinetic energy for a successful collision.B. Curve 2 is at a higher temperature than curve 1 and a lower fraction of the colliding particles possess sufficient kinetic energy for a successful collision.C. Curve 1 is at a higher temperature than curve 2 and a higher fraction of the colliding particles possess sufficient kinetic energy for a successful collision.D. Curve 2 is at a higher temperature than curve 1 and a higher fraction of the colliding particles possess sufficient kinetic energy for a successful collision.

Answers to Multiple Choice

1D 13A 25E 37B 49C 61C 73E2C 14D 26E 38A 50A 62A 74B3C 15B 27A 39E 51B 63D 75E4D 16B 28D 40D 52C 64A 76D5B 17E 29B 41D 53C 65B 77D6D 18B 30B 42A 54A 66D 78D7B 19B 31D 43B 55D 67A 79A8D 20A 32C 44B 56A 68C 80A9D 21C 33C 45E 57B 69C 81A

10C 22D 34D 46C 58A 70A 82E11D 23E 35C 47D 59B 71B 83D12D 24E 36D 48B 60D 72D 84D


Documents

1arcuricacid.weebly.com/uploads/2/3/1/0/23106948/ch12unit... · Web viewUnit 1 Provincial Practice Questions – Multiple Choice 1. As an activated complex changes into products,