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THE OFFICIAL STUDY GUIDE FOR:
“CHEMICAL KINETICS”
Multiple Choice Section : This study guide is a compilation of questions from provincial exams since April 1994. I urge you to become intimately familiar with question types. You will notice that questions from one year to another are very similar in their composition. Identification of question types will allow you to be more efficient in answering these questions on the provincial examination. My recommendations for using this study guide are as follows :
- DO ALL THE QUESTIONS in this booklet. These are actual Provincial Exam questions! Your own provincial exam and unit test will include questions similar to the ones in this booklet!
- RESIST THE URGE TO LOOK AT THE ANSWER KEY until you have given all the questions in the section your best effort. Don’t do one question, then look at the key, then do another and look at the key, and so on. Each time you look at one answer in the study guide, your eye will notice other answers around them, and this will reduce the effectiveness of those questions in helping you to learn.
- LEARN FROM YOUR MISTAKES! If you get a question wrong, figure out why! If you are having difficulty, talk to your study partner , or maybe phone someone in your Peer Tutoring group. Get together with group members or other students from class and work on these questions together. Explain how you got your answers to tough questions to others. In explaining yourself to someone else, you will learn the material better yourself (try it!) Ask your teacher to explain the questions to you during tutorial or after school. Your goal should be to get 100% on any Chemistry 12 multiple choice test - learning from your mistakes in this booklet will really help you in your efforts to meet this goal!
- This is REALLY CRUCIAL : DO NOT mark the answer anywhere on the questions themselves. For example, do not circle any of options A B C or D-instead use a different sheet of paper to place your answers on. By avoiding this urge, you can re-use this study guide effectively again, when preparing for your final exam. In the box to the left, put an asterisk or small note to yourself to indicate that you got the question wrong and need to come back to it. If you got the question correct initially, a check mark might be assurance that you understand this type of question and therefore can concentrate on other questions that present a challenge to you.
- Check Off the STATUS box on the PRESCRIBED LEARNING OUTCOMES sheet. I have tried to organize the questions in the identical sequence to which they appear on your Acid Base Prescribed Learning Outcome sheet. By doing this, you can be confident that you know everything you need to know for both the UNIT EXAM and PROVINCIAL EXAM!
TABLE OF CONTENTS:
INTRODUCTION TO REACTION KINETICS 1 COLLISION THEORY 6 REACTION MECHANISMS AND CATALYSTS 17 ANSWERS 21
INTRODUCTION
- A2 (^) The rate of a chemical reaction can be expressed in A. grams per mole. B. energy consumed per mole. C. volume of gas per unit time. D. moles formed per litre of solution.
- A2 (^) Consider the following reaction:
Under certain conditions, the rate of decomposition of NO 2 is 3.2 × 10 -3^ mol/s. The rate of formation of O 2 is: A. 1.6 × 10 -3^ mol/s B. 3. 2 × 10 -3^ mol/s C. 4.8 x10 -3^ mol/s D. 6. 4x10 -3^ mol/s
- A2 (^) Consider the following reaction:
At a certain temperature the rate of decomposition of N 2 O 5 is 2.5 × 10 -6^ mol/s. The rate of formation of NO 2 is: A. 1.0 × 10 -5^ mol/s B. 1.3 × 10 -6^ mol/s C. 2.5 × 10 -6^ mol/s D. 5.0 × 10 -6^ mol/s
- A2 (^) Consider the following reaction:
The rate of formation of NH 3 is 3.0 mL/min. The rate of consumption of H 2 is A. 1.5mL/min B. 2.0mL/min C. 4.5mL/min D. 9.0mL/min
- A2 (^) Which of the following units can be used to express the rate of a chemical reaction? A. mL/g B. mol/L C. g/mol D. mol/min
- A2 (^) Consider the following reaction:
The rate of this reaction can be expressed as...
- A2 (^) The rate of a chemical reaction is equal to the slope of a graph with the axes labeled:
- A
- A2 (^) Consider the following reaction:
Which graph shows the relationship between rate of consumption of H 2 O 2 and time?
- A3 (^) Consider the reaction:
A 0.040 mol piece of aluminum reacted completely in 20s. The rate of formation of hydrogen gas is
A. 0. 0013 mol/s B. 0. 0020 mol/s C. 0. 0030 mol/s D. 0. 0060 mol/s
- A3 (^) A 25.0 mL sample of hydrogen peroxide decomposes producing 50.0mL of oxygen gas in 137 s.
The rate of formation of O 2 in mL/min is: A. 0.182 mL/min B. 0.365 mL/min C. 10.9 mL/min D. 21.9 mL/min
- A3 (^) At 30°C, a 25.0mL sample of bleach decomposes producing 50.0mL of oxygen gas in 80 seconds. The
rate of oxygen formation can be determined by the expression: A. 50.0 mL/80 s B. 50.0 mL/30° C C. 25.0 mL/80 s D. 25.0 mL/3 0 °C
- A3 (^) Consider the reaction:
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 B. 0.0833 mol/min C. 0.125 mol/min D. 5.00 mol/min
- A4 (^) Consider the following reaction:
The rate of this reaction could be determined by monitoring the change in concentration of: A. H +^ B. Cl –^ C. Na +^ D. H 2 O
- A4 (^) Consider the following reaction at constant temperature in an open system:
Which of the following properties could be used to determine reaction rate? A. mass of the system B. pressure of the gas C. concentration of H 2 O D. concentration of MgCO 3
- A4 (^) Magnesium metal reacts rapidly with hydrochloric acid in an open beaker to produce aqueous magnesium chloride and hydrogen gas. Which of the following could be used to measure the rate of this reaction? A. the volume of the solution B. the colour of gas produced C. the concentration of the chloride ion D. the mass of the beaker and its contents
- A4 (^) Which of the following properties could be used to measure the rate of the following reaction taking place in an open container?
A. mass of Zn B. solubility of HCl C. concentration of Cl−^ D. colour of the solution
24. A5 Consider the following reaction:
The rate of this reaction could be increased by
A. decreasing temperature. B. adding a catalyst.
C. increasing the concentration of S(s) D. increasing the concentration of S O3( g ).
- A5 (^) Which combination of factors will affect the rate of the following reaction?
A. temperature and surface area only B. temperature and concentration only C. concentration and surface area only D. temperature, concentration and surface area
- A5 (^) In general, reaction rates double when the temperature is increased by 1 0° C. The temperature
of a reaction is increased by 4 0° C. The rate of the reaction will increase by a factor of:
A. 2 B. 4 C. 8 D. 16
27. A5 Consider the following reaction:
The rate of decomposition of the oxalate ion is increased by
A. adding NaOH. B. removing CO 2 C. adding a catalyst D. decreasing the pressure
- A5 (^) Consider the following reaction:
To increase the rate of decomposition of CaCO 3 , one could A. add CO 2 B. remove CO 2 C. increase the temperature. D. decrease the temperature.
- A5 (^) Consider the following reaction:
The rate of reaction is increased by A. adding a catalyst. B. removing some O 2 C. decreasing the temperature. D. increasing the volume of the container.
- A6 (^) An untreated sugar cube does not burn when held over a lighted match. A sugar cube coated with cigarette ash readily ignites and burns. All of the cigarette ash remains after the reaction. The factor that caused this change in rate is the A. nature of reactants. B. presence of a catalyst.
C. increase in surface area. D. increase in concentration.
- A6 Consider the following factors: I. Concentration of reactants. II. Temperature of reactants. III. Surface area of reactants. The factors that affect the rate of a chemical reaction between two gases are A. I and II only. B. I and III only. C. II and III only. D. I, II and III.
- A6 (^) Which of the following are necessary for successful collisions to occur? I. Favourable collision geometry. II. Sufficient kinetic energy. III. Large ∆H. A. I only B. I and II only C. II and III only D. I, II and III
- A6 (^) Dust particles suspended in the air inside unheated grain elevators can sometimes react explosively because the dust particles have a A. high kinetic energy. B. high activation energy. C. catalytic effect on the reaction. D. large surface area for the reaction.
- A6 (^) Which of the following factors affects the rate of heterogeneous reactions only? A. nature of reactants B. temperature of system C. surface area of reactants D. concentration of reactants
- B1 (^) Consider the following collisions, each occurring at the same temperature: Which one of the following factors explains why collision one is successful while collision two is not successful?
A. Catalyst. B. Geometry. C. Concentration. D. Kinetic energy.
- B1 (^) Consider the following reaction:
As the temperature of the above system is increased, the number of collisions A. increases but fewer are effective. B. decreases and fewer are effective. C. increases and more are effective. D. decreases but more are effective.
- B1 (^) Consider the following factors: I. reactant particles collide II. sufficient kinetic energy is present III. a favourable geometry exists IV. catalysts are present
Which combination of the above factors is required for all successful collisions? A. I only B. II and III only C. I, II and III only D. I, II, III and IV
41. B1 Consider the following:
To increase the rate of a reaction there must be an increase in A. I only. B. I and III only. C. I, III and IV only. D. I, II, III and IV.
- B1 (^) Milk is refrigerated in order to slow the rate of decomposition by bacterial action. The decrease in reaction rate is due to A. a decrease in surface area. B. a decrease in ∆H for the reaction. C. a decrease in the fraction of particles possessing sufficient energy. D. the introduction of an alternate pathway with greater activation energy.
- B1 (^) 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.
- B1 (^) For collisions to be successful, reactants must have A. favourable geometry only. B. sufficient heat of reaction only. C. sufficient potential energy only. D. sufficient kinetic energy and favourable geometry.
- B1 (^) To increase the rate of a reaction, there must be A. a decrease in the frequency of collisions. B. an increase in the frequency of collisions. C. a decrease in the frequency of successful collisions. D. an increase in the frequency of successful collisions.
- B1 (^) An increase in temperature increases the rate of a chemical reaction because A. the activation energy is lower. B. exothermic reactions are always favoured. C. a greater fraction of particles have sufficient kinetic energy. D. the particles are more likely to have favourable collision geometry.
- B1 (^) Which of the following will decrease the number of effective collisions during a chemical reaction? A. Adding a catalyst. B. Increasing the surface area. C. Decreasing the temperature. D. Increasing reactant concentrations.
- B1 (^) 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.
- B1 (^) The average kinetic energy of colliding particles can be increased by A. adding a catalyst. B. increasing pressure.
C. increasing temperature. D. increasing reactant concentration.
- B2 (^) An activated complex has A. low potential energy and is stable. B. high potential energy and is stable.
C. low potential energy and is unstable. D. high potential energy and is unstable.
- B2 (^) An activated complex is a chemical species that is A. stable and has low PE. B. stable and has high PE. C. unstable and has low PE. D. unstable and has high PE.
- B3 Activation energy can be described as the A. energy of motion. B. energy of the activated complex. C. energy difference between the reactants and the products. D. energy difference between the reactants and the activated complex.
- B3 (^) The minimum amount of energy needed to start a reaction is called the A. activation energy B. energy of reaction C. entropy of reaction D. reaction mechanism energy
- B3 (^) The activation energy of a reaction in solution A. increases with the addition of a catalyst. B. decreases with a decrease in temperature. C. increases if the solution is stirred vigorously. D. does not change with an increase in temperature.
- B3 (^) The minimum amount of energy required to overcome the energy barrier in a chemical reaction is the
A. heat of reaction. B. activation energy. C. KE of the reactants. D. enthalpy of the products.
- B4 (^) A certain reaction is able to proceed by various mechanisms. Each mechanism has a different E a and results in a different overall rate. Which of the following best describes the relationship between the E a values and the rates?
- B5 Which of the following changes will increase the average kinetic energy of reactant molecules? A. adding a catalyst B. increasing the temperature C. increasing the surface area D. increasing the concentration
- B5 (^) As reactant molecules approach each other A. heat is released. B. a reaction intermediate forms. C. kinetic energy changes to potential energy. D. potential energy changes to kinetic energy.
- B5 (^) As reactant particles approach one another, their A. kinetic energy increases and their potential energy increases. B. kinetic energy increases and their potential energy decreases. C. kinetic energy decreases and their potential energy increases. D. kinetic energy decreases and their potential energy decreases.
- B5 (^) Which of the following describes the energy of colliding particles as reacting molecules approach each other?
- B5 (^) The changes in PE and KE, as reactant molecules approach each other, can be represented by:
66. B6 Consider the following potential energy diagram that represents two different reactions.
Which of the following statements is correct? A. Reactions A and B are both exothermic. B. Reactions A and B are both endothermic. C. Reaction A is exothermic and reaction B is endothermic. D. Reaction A is endothermic and reaction B is exothermic.
- B6 Consider the following potential energy diagram for a reversible reaction:
Which of the following describes the system above?
- B6 Consider the following potential energy diagram:
Which of the following represents the heat of reaction, ∆H, for the forward reaction?
A. I B. II C. III D. IV
69. B6 Consider the following potential energy diagram:
The energy interval that represents the
activation energy for the reverse reaction is:
A. I B. II C. III D. IV
- B6 (^) 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.
- B6 (^) Consider the following reaction:
The activation energy for the formation of HI is 167 kJ. The activation energy for the decomposition of HI is A. 28 kJ B. 139 kJ C. 167 kJ D. 195 kJ
- B6 (^) Consider the following reaction:
The activation energy for the formation of HI is 167 kJ and for the decomposition of HI is 139 kJ. The reaction for the formation of HI is: A. exothermic and the ∆H = -28 kJ B. exothermic and the ∆H = +28 kJ C. endothermic and the ∆H = -28 kJ D. endothermic and the ∆H = +28 kJ
- B6 (^) Consider the following potential energy diagram:
The activation energy for the reverse reaction is A. 30 kJ B. 140 kJ C. 170 kJ D. 200 kJ
78. B6 Consider the following potential energy diagram:
The forward reaction is
A. exothermic and the ∆H = -50 kJ
B. endothermic and the ∆H = +50 kJ
C. exothermic and the ∆H = -225 kJ
D. endothermic and the ∆H = +225 kJ
- B6 (^) Consider the following reaction:
CO + NO 2 → CO 2 + NO ∆H = -234 kJ
The activation energy of the forward reaction is 134 kJ. What is the activation energy for the reverse reaction? A. -134 kJ B. -100 kJ C. 234 kJ D. 368 kJ
- B6 (^) Consider the following PE diagram:
- B6 (^) Consider the following PE diagram for a reversible reaction:
Which of the following describes this reaction?
- B6 (^) Consider the following PE diagram:
Which of the following describes the forward reaction?
- B
- B
91. B9 Consider the following reactions:
Increasing the surface area will increase the reaction rate in
A. II only B. I and III only C. II and III only D. I, II and III
- B9 (^) Which of the following reactions occurs most rapidly at room temperature?
- B9 (^) Which of the following would react most rapidly?
A. Powdered Zn in 1.0 M HCl at 25° C B. Powdered Zn in 2.0 M HCl at 40° C C. A lump of Zn in 2.0 M HCl at 25° C D. A lump of Zn in 1.0 M HCl at 40° C
- B
- B9 (^) Consider the following reaction:
The rate of this reaction increases when more magnesium is added. This change is caused by the A. addition of a catalyst. B. increase in surface area. C. change in nature of the reactants. D. increase in concentration of reactants.
- B9 (^) At room temperature, which of the following reactions is fastest?
REACTION MECHANISMS AND CATALYSTS
- C2 (^) Consider the following two-step reaction mechanism:
Which one of the following changes would result in the greatest increase in reaction rate? A. increase [CO] B. decrease [NO] C. increase [NO 2 ] D. decrease [NO 3 ]
- C
- C2 (^) In a reaction mechanism, the rate determining step is the A. fastest and has the lowest activation energy. B. fastest and has the highest activation energy. C. slowest and has the lowest activation energy. D. slowest and has the highest activation energy.
- C3 What effect does a catalyst have on a reaction? A. It changes the ∆H of a reaction. B. It increases the kinetic energy of the reactants. C. It decreases the potential energy of the products.
D. It provides a reaction mechanism with a lower activation energy.
- C3 (^) When a catalyst is added to a reaction: I. the heat of reaction increases II. a new mechanism is provided III. the equilibrium constant increases
A. II only B. I and II only C. II and III only D. I, II and III
- C4 (^) Consider the following PE diagram:
Which of the following describes this reaction?
- C5 Consider the following mechanism for a reaction:
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.
113. C5 Consider the following reaction mechanism:
Step 1: M + X → MX Step 2: MX + A → D + X
The chemical species MX is a(n)
A. catalyst. B. inhibitor. C. final product. D. reaction intermediate.
- C5 (^) Consider the following reaction mechanism:
Step 1: ICl + H 2 → HI + HCl (slow) Step 2: ICl + HI → HCl + I 2 (fast)
The species HCl is a
A. product. B. catalyst. C. reactant. D. reaction intermediate.
- C5 (^) Consider the following reaction mechanism: Step 1: H 2 O 2 + I −^ → H 2 O + IO− Step 2: H 2 O 2 + IO−^ → H 2 O + O 2 + I − The reaction intermediate is A. I − B. IO −^ C. H 2 O D. H 2 O 2
116. C5 Consider the following reaction mechanism:
The reaction intermediate is
A. Cu+^ B. Cu2+^ C. V3+^ D. Fe3+
- C5 (^) Consider the following reaction mechanism:
The catalyst is: A. O 2 B. O 3 C. NO D. NO 2
118. C5 Consider the following reaction mechanism:
A reactant in the overall reaction is:
A. O B. O 2 C. N 2 D. N 2 O
119. C5 Consider the following reaction mechanism:
The reaction intermediate is
A. Cl B. O 2 C. O 3 D. ClO
120. C5 Consider the following reaction mechanism:
The product in the overall reaction is
A. O 2 B. O 3 C. NO D. NO 2
121. C5 Consider the following reaction mechanism:
In the overall reaction, N 2 O 4 is a
A. product. B. catalyst. C. reactant. D. reaction intermediate.
- C5 (^) Consider the following reaction mechanism:
In this reaction, H 2 is a
A. product. B. catalyst. C. reactant. D. reaction intermediate.
- C5 (^) A substance that increases the rate of a chemical reaction and may be recovered unchanged at the end of the reaction is a(n) A. product. B. catalyst. C. activated complex. D. reaction intermediate.
ANSWER KEY:
Introduction:
