Deck 13: Chemical Kinetics: Reactions in the Atmosphere

Question 1

The order in which ozone, nitrogen monoxide, and nitrogen dioxide build up in the atmosphere over the course of the day is ________, then ________, then ________.

A)NO; NO₂; O₃
B)NO; O₃; NO₂
C)NO₂; NO; O₃
D)NO₂; O₃; NO
E)O₃; NO; NO₂

Answer 1

NO; NO₂; O₃

Question 2

Indicate which of the following compounds is not a component of photochemical smog.

A)O₃
B)H₂O
C)NO₂
D)NO
E)organic molecules

Answer 2

H₂O

Question 3

Indicate which of the following compounds is a component of photochemical smog.

A)H₂O
B)CO₂
C)N₂O
D)O₃
E)CO

Answer 3

O₃

Question 4

Which of the following is not important as a contributing factor to photochemical smog?

A)stagnant air
B)sunlight
C)lots of traffic
D)irrigation
E)cars without catalytic converters

Question 5

For the reaction 2A + 3B →4C +5D, the rate of the reaction in terms of $\Delta$ D would be written as ________

A)( )
B)( )
C)( )
D)( )
E)( )

Question 6

NO₂ contributes to the "brown haze" associated with photochemical smog events. At what time of day is NO₂ concentration highest?

A)in the morning before rush hour
B)in the morning just after rush hour
C)midmorning
D)noon
E)midafternoon

Question 7

For the reaction 2A 4B + 3D, the rate of the reaction in terms of $\Delta$ B would be written as ________

A)( )
B)( )
C)(- )
D)(+ )
E)( )

Question 8

One reaction that occurs in an automobile catalytic converter is the conversion of carbon monoxide to carbon dioxide. How is the rate of this reaction related to the rate at which the concentration of a reactant or product changes?
2CO(g) + O₂(g) →2CO₂(g)
I. Rate =
II. Rate =
III. Rate =
IV. Rate =

A)I only
B)II only
C)III only
D)II and III only
E)II, III, and IV only

Question 9

Large cities often issue ozone advisories. At what time of year would an advisory be likely to occur most often?

A)winter
B)spring
C)summer
D)fall
E)No season should have more advisories than another.

Question 10

NO₂ concentrations during photochemical smog events often have two peaks, one in the early morning (8 A.M.) and another, smaller peak around 7 P.M. The second peak is due to ________

A)NO₂ emissions produced during the evening rush hour.
B)the reaction of NO and O₃.
C)the photochemical formation of O₃.
D)automobile NO emissions reacting with oxygen.
E)all of the above.

Question 11

Octane can undergo combustion to produce carbon dioxide and water and release tremendous amounts of energy. The balanced chemical equation for this reaction is shown below. How could the rate of this reaction be expressed correctly in terms of the rate at which the concentration of a reactant or product changes?

A)Rate =
B)Rate =
C)Rate =
D)Rate =
E)Rate =

Question 12

The greatest NO concentration is observed ________

A)in the morning before rush hour.
B)in the morning just after rush hour.
C)in midmorning.
D)at noon.
E)in midafternoon.

Question 13

At what time of day are ozone concentrations highest during a photochemical smog event?

A)in the morning before rush hour
B)in the morning just after rush hour
C)midmorning
D)noon
E)midafternoon

Question 14

The difference between an average rate and an instantaneous rate is ________

A)the average rate is taken over a longer time period.
B)the instantaneous rate is taken from the slope of the curve at a specific time.
C)They are not different if the time interval chosen is small enough.
D)All of the above are correct.

Question 15

For the reaction 2A + 3B 4C + 5D, the rate of the reaction in terms of $\Delta$ A would be written as ________

A)( )
B)(- )
C)( )
D) ( )
E)( )

Question 16

Smog created by the interaction of sunlight with nitrogen oxides and volatile organic compounds is termed ________ smog.

A)photolytic
B)photochemical
C)photophysical
D)acid
E)sulfurous

Question 17

The device in automobiles that has decreased NO and partially oxidized hydrocarbons from exhaust gases is termed a ________

A)catalytic intermediate.
B)photochemical inhibitor.
C)catalytic linker.
D)nitrogen monoxide reducer.
E)catalytic converter.

Question 18

One reaction that contributes to acid rain is the conversion of dinitrogen pentoxide to nitric acid upon reaction with water. How could the rate of this reaction be expressed correctly in terms of the rate at which the concentration of a reactant or product changes?
N₂O₅(g) + H₂O(g) 2HNO₃(g)

A)Rate =
B)Rate =
C)Rate =
D)Rate =
E)Rate=

Question 19

One reaction that occurs in an automobile catalytic converter is the conversion of nitrogen monoxide to nitrogen and oxygen. How could the rate of this reaction be expressed correctly in terms of the rate at which the concentration of a reactant or product changes?
2NO(g) N₂(g) + O₂(g)

A)Rate =
B)Rate =
C)Rate =
D)Rate =
E)Rate =

Question 20

One reaction that occurs in an automobile catalytic converter is the conversion of nitrogen monoxide to nitrogen and oxygen. How is the rate of this reaction related to the rate at which the concentration of a reactant or product changes?

2NO(g) →N₂(g) +O₂(g)
I. Rate =
II. Rate =
III. Rate =
IV. Rate =

A)I only
B)II only
C)III and IV only
D)I, III, and IV only
E)II, III, and IV only

Question 21

From the following concentration versus time plot for four different reactions, which has the greatest instantaneous rate of disappearance at the time indicated by the arrow?

A)I
B)II
C)III
D)IV
E)All have the same rate.

Question 22

In the combustion of methane, , which reactant has the greatest rate of disappearance?

A)CH₄
B)O₂
C)CO₂
D)H₂O
E)CH₄ and O₂ have the same rate of disappearance.

Question 23

Which of the following is a possible graph of concentration versus time for a reaction product?

A)
B)
C)
D)

Question 24

A scientist conducts an experiment to determine the rate of NO formation in the reaction: If the initial concentration of N₂ was 0.500 M and the concentration of N₂ was 0.450 M after 0.100 s, what is the average rate of NO formation?

A)0.500 M/s
B)1.00 M/s
C)5.00 M/s
D)10.0 M/s
E)0.250 M/s

Question 25

The following graph shows the kinetics curves for the reaction of oxygen with hydrogen to form water: . Which curve is hydrogen?

A)the dashed curve
B)the gray curve
C)the black curve
D)either the gray or the black curve
E)Any of these curves could be hydrogen.

Question 26

If the rate of appearance of O₂ in the reaction: is 0.250 M/s over the first 5.50 s, how much oxygen will form during this time?

A)1.38 M
B)4.13 M
C)0.69 M
D)0.25 M
E)0.46 M

Question 27

If the rate of the reaction: is 0.870 M/s over the first 12.25 s, how much hydrogen sulfide will be consumed during this time?

A)10.66 M
B)21.32 M
C)5.33 M
D)31.98 M
E)3.55 M

Question 28

Which of the following is not a possible graph of concentration versus time for a reactant?

A)
B)
C)
D)

Question 29

From the following concentration versus time plot for four different reactions, which has the greatest instantaneous rate of disappearance at the time indicated by the arrow?

A)I
B)II
C)III
D)IV
E)All have the same rate of change.

Question 30

HI dissociates to form I₂ and H₂: If the concentration of HI changes at a rate of -0.45 M/s, what is the rate of appearance of I₂(g)?

A)0.90 M/s
B)0.45 M/s
C)0.23 M/s
D)1.00 M/s
E)0.13 M/s

Question 31

The following graph shows the kinetics curves for the reaction of oxygen with hydrogen to form water: . Which curve is water?

A)the dashed curve
B)the gray curve
C)the black curve
D)either the gray or the black curve
E)Any of these curves could be water.

Question 32

A scientist conducts an experiment to determine the rate of the following reaction: If the initial concentration of H₂ was 0.150 M and the concentration of H₂ was 0.050 M after 2.10 s, what is the average rate of the reaction?

A)0.048 M/s
B)0.016 M/s
C)0.144 M/s
D)0.072 M/s
E)0.032 M/s

Question 33

If the rate of formation of dinitrogen is 0.540 M/s, what is the rate of formation of water?

A)0.540 M/s
B)0.180 M/s
C)0.270 M/s
D)1.62 M/s
E)3.24 M/s

Question 34

Assuming that each of the following graphs has the same concentration and time axes, which has the greatest initial rate of disappearance of reactant?

A)
B)
C)
D)

Question 35

A scientist conducts an experiment to determine the rate of the following reaction: If the initial concentration of NO was 0.00 M and the concentration of NO was 0.050 M after 0.100 s, what is the average rate of the reaction?

A)0.500 M/s
B)1.00 M/s
C)5.00 M/s
D)10.0 M/s
E)0.250 M/s

Question 36

If the rate of formation of dinitrogen is 0.540 M/s, what is the rate of disappearance of oxygen?

A)0.810 M/s
B)1.08 M/s
C)1.62 M/s
D)0.360 M/s
E)0.540 M/s

Question 37

If the rate of formation of nitrogen monoxide is 0.413 M/s, what is the rate of disappearance of SO₂?

A)0.207 M/s
B)0.280 M/s
C)0.413 M/s
D)0.620 M/s
E)1.24 M/s

Question 38

If the rate of formation of ammonia is 0.345 M/s, what is the rate of disappearance of H₂?

A)0.345 M/s
B)0.230 M/s
C)1.04 M/s
D)0.690 M/s
E)0.518 M/s

Question 39

Using the reaction shown below, which statement is correct?

A)The concentration of all compounds are changing by the same amount at all times.
B)The HCl concentration increases at the same rate as the concentration of iodine.
C)The concentration of hydrogen decreases at the same rate as the concentration of ICl.
D)The concentration of HCl increases twice as fast as the concentration of iodine.
E)None of these statements is correct.

Question 40

If the rate of formation of ammonia is 0.345 M/s, what is the rate of disappearance of N₂?

A)0.173 M/s
B)0.345 M/s
C)0.690 M/s
D)245 M/s
E)0.518 M/s

Question 41

The rate law of a particular reaction was determined to be Rate = k. What is the unit of the rate constant for the reaction?

A)M/s
B)1/(Ms)
C)1/(Ms²)
D)1/s
E)Ms

Question 42

For the rate law Rate = k[A][B]^1/2, the partial order with respect to A is ________, the partial order with respect to B is ________, and the total order is ________.

A)
B)
C)
D)
E)The orders cannot be determined without a chemical reaction.

Question 43

The half-life (t_1/2) of a first-order reaction is 0.100 s. What is the rate constant?

A)6.93 s^-1
B)0.693 s^-1
C)0.0693 s^-1
D)0.144 s^-1
E)3.01 s^-1

Question 44

In a rate law, the partial orders are determined by ________

A)the reactant concentrations.
B)the stoichiometric coefficients.
C)the product concentrations.
D)experiment.
E)the difference between the forward and reverse rates.

Question 45

If the reaction 3A + B + C 2D + E is first order overall, which of these could be the units of its rate constant, k?

A)1/s
B)M/s
C)1/Ms
D)1/Ms²
E)Ms

Question 46

In a first order reaction, the initial concentration of A is 0.40 M. What is the concentration of A after 15 seconds if the half-life of the reaction is 3 seconds?

A)8.0 $\times$ 10^-2 M
B)2.0 M
C)5.0 $\times$ 10^-2 M
D)2.5 $\times$ 10^-2 M
E)1.3 $\times$ 10^-2 M

Question 47

A second-order reaction (2A B) with a rate constant of 0.350 M ^-1s ^-1 is found to have a half-life of 3.45 s. What was the initial concentration of the reactant, [A]₀?

A)0.828 M
B)0.201 M
C)1.00 M
D)1.21 M
E)0.350 M

Question 48

The reaction A(g) + B(g) C(g) has the following rate law: Rate = k[A]²[B]. If the concentration of A is tripled while the concentration of B is doubled, the rate will increase by a factor of ________.

A)9
B)18
C)12
D)6
E)24

Question 49

If the rate of formation of ammonia is 0.345 M/s, what is the rate of disappearance of N₂?

A)0.173 M/s
B)0.345 M/s
C)0.690 M/s
D)245 M/s
E)0.518 M/s

Question 50

The reaction is first order in B and A. The overall order of the reaction is ________

A)first.
B)second.
C)third.
D)zero.
E)fourth.

Question 51

Ammonia gas (NH₃) is produced from hydrogen and nitrogen gas according to the following reaction: If the rate of production of ammonia is R(NH₃), what is the rate of loss of hydrogen and nitrogen gas, respectively?

A)(-R(H₂) = 2/3 R(NH₃); -R(N₂) = 1/2 R(NH₃))
B)(-R(H₂) = 3/2 R(NH₃); -R(N₂) = 2 R(NH₃))
C)(-R(H₂) = 3/2 R(NH₃); -R(N₂) = 1/2 R(NH₃))
D)(-R(H₂) = 2/3 R(NH₃); -R(N₂) = 2 R(NH₃))
E)(-R(H₂) = R(NH₃); -R(N₂) = R(NH₃))

Question 52

The reaction A(g) + B(g) C(g) has the following rate law: Rate = k[A]^1/2[B]². If the concentration of A is quadrupled while the concentration of B is halved, the rate will change by a factor of ________.

A)0.25
B)0.50
C)2
D)4
E)16

Question 53

A reaction is first order in A. If the rate constant of the reaction is 3.45 $\times$ 10^-3 s^-1, what is the half-life (t_1/2) of the reaction?

A)4.98 $\times$ 10^-3 s
B)200 s
C)3.45 $\times$ 10^-3 s
D)100 s
E)1.73 $\times$ 10^-3 s

Question 54

For the rate law Rate = k[A]^1/2[B], the partial order with respect to A is ________, the partial order with respect to B is ________, and the total order is ________.

A)
B)
C)
D)
E)The orders cannot be determined without a chemical reaction.

Question 55

For the rate law Rate = k[A]^5/2[B], the partial order with respect to A is ________, the partial order with respect to B is ________, and the total order is ________.

A)
B)
C)
D)
E)The orders cannot be determined without a chemical reaction.

Question 56

The second-order reaction A B is found to have a rate constant of 0.978 M ^-1s ^-1. What is the half-life of this reaction when [A]₀ = 0.0300 M ?

A)0.0293 s
B)0.710 s
C)34.1 s
D)60.1 s
E)24.3 s

Question 57

The rate law of a particular reaction was determined to be Rate = k[A][B]. What is the unit of the rate constant for the reaction?

A)M/s
B)1/(Ms)
C)1/(Ms²)
D)1/s
E)Ms

Question 58

The reaction CHCl₃(g) + Cl₂(g) CCl₄(g) + HCl(g) has the following rate law: Rate = k[CHCl₃][Cl₂]. If the concentration of CHCl₃ is increased by a factor of five while the concentration of Cl₂ is kept the same, the rate will ________

A)double.
B)triple.
C)stay the same.
D)increase by a factor of five.
E)decrease by a factor of one-fifth.

Question 59

The disappearance of HI in the reaction is shown in the following figure. What is the instantaneous rate of this reaction at t = 5 s if the instantaneous rate of change of [HI] is 0.02 M/s?

A)0.2 M/s
B)0.01 M/s
C)0.02 M/s
D)0.100 M/s
E)0.04 M/s

Question 60

Which of these could be the units of the rate constant for a first-order reaction?

A)M/s
B)1/Ms
C)1/Ms²
D)1/s
E)Ms

Question 61

Which of the following plots indicates that the reaction is second order?

A)
B)
C)
D)

Question 62

Which of the following plots would indicate that a reaction was first order?

A)
B)
C)
D)

Question 63

The linear form of the Arrhenius equation is very useful, as it allows us to calculate the ________ from the slope and the ________ from the intercept.

A)frequency factor; activation energy
B)initial concentration; activation energy
C)activation energy; frequency factor
D)activation energy; Boltzmann constant
E)transition state; steric factor

Question 64

Which of the following plots indicates that the reaction is zero order?

A)
B)
C)
D)

Question 65

Chlorine dioxide (ClO₂) is used as a disinfectant in municipal water-treatment plants. It decomposes in a first-order reaction with a rate constant of 0.0714 s^-1. If the initial concentration were 0.12 M, what would the concentration be after 14.0 s has elapsed?

A)0.033 M
B)0.12 M
C)0.060 M
D)0.012 M
E)0.044 M

Question 66

Which plot would provide the activation energy for a reaction?

A)
B)
C)
D)

Question 67

N₂O₅ is used as a source of NO₂ in chemical reactions. The compound decomposes in a first order reaction. If the initial concentration of N₂O₅ = 0.400 M, and the concentration is 0.025 M after 120 seconds, what is the rate constant k of the reaction?

A)7.50 s^-1
B)333 s^-1
C)2.77 s^-1
D)2.31 $\times$ 10^-2 s^-1
E)5.21 $\times$ 10^-4 s^-1

Question 68

Which point in the reaction profile below represents a transition state?

A)II and IV
B)II only
C)III
D)IV only
E)V

Question 69

How many steps are involved in the following reaction?

A)None
B)One
C)Two
D)three
E)cannot be determined

Question 70

Which point as labeled by an asterisk (*) on the following energy profile is the transition state?

A)
B)
C)
D)

Question 71

The energy profiles for four different reactions are shown below. The scales are the same for each. Which reaction requires the most energetic collisions to reach the transition state?

A)a
B)b
C)c
D)d

Question 72

The energy profiles for four different reactions are shown below. The scales are the same for each. Which reaction requires the least energetic collisions to reach the transition state?

A)a
B)b
C)c
D)d

Question 73

Collision theory assumes that the rate of a reaction depends on ________

A)the energy of collisions.
B)the orientation of colliding molecules.
C)the energy of collisions and the orientation of colliding molecules.
D)the change in energy between the products and the reactants.
E)the change in free energy between the reactants and products.

Question 74

Which point in the reaction profile below represents an intermediate?

A)II and IV
B)II only
C)III
D)IV only
E)V

Question 75

The energy needed to form an activated complex is called ________

A)collision energy.
B)kinetic energy.
C)activation energy.
D)potential energy.
E)thermodynamic energy.

Question 76

Sodium hypochlorite (NaClO) is used as a common disinfectant. It decomposes in a first-order process with a rate constant of 0.10 s^-1. How long would it take for an initial concentration of 0.20 M to decrease to 0.07 M ?

A)0.50 s
B)5.43 s
C)10.5 s
D)35.7 s
E)92.9 s

Question 77

Consider the rate law expression Rate = k[A][B]². Which of the following is not true about the reaction?

A)The reaction is second order in B.
B)The reaction is first order in A.
C)The reaction is overall third order.
D)Doubling the concentration of B will double the rate.
E)All statements (A-D) are true.

Question 78

The first-order reaction A B, has k = 5.67 s^-1. If [A]₀ = 0.500 M, how long will it take to reach [A] = 0.124 M ?

A)0.122 s
B)0.100 s
C)8.18 s
D)0.246 s
E)0.488 s

Question 79

The linear form of ________ is very useful, as it allows us to calculate the activation energy and the frequency factor.

A)the Boltzmann equation
B)the Arrhenius equation
C)Planck's equation
D)the rate law
E)the integrated rate law

Question 80

The reaction 2NO(g) + O₂(g) 2NO₂(g) has the following rate law: Rate = k[O₂][NO]². If the concentration of NO is reduced by a factor of two, the rate will ________

A)double.
B)quadruple.
C)be reduced by one-quarter.
D)be reduced by one-half.
E)remain the same.