SLIDE 1 1 A burning splint will burn more vigorously in pure
- xygen than in air because
A
- xygen is a reactant in combustion and
concentration of oxygen is higher in pure
B
- xygen is a catalyst for combustion.
C
- xygen is a product of combustion.
D nitrogen is a product of combustion and the system reaches equilibrium at a lower temperature. E nitrogen is a reactant in combustion and its low concentration in pure oxygen catalyzes the combustion.
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2 As the temperature of a reaction is increased, the rate of the reaction increases because the __________. A reactant molecules collide less frequently B reactant molecules collide more frequently and with greater energy per collision C activation energy is lowered D reactant molecules collide less frequently and with greater energy per collision E reactant molecules collide more frequently with less energy per collision
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3 Which of the following will not affect the rate of a chemical reaction? A increasing the concentration of a reactant B decreasing the concentration of a reactant C increasing the temperature at which the reaction is carried out D performing the reaction in the presence of a catalyst E All of the above will affect the rate of a chemical reaction.
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SLIDE 2
4 A reaction was found to be first order in carbon monoxide concentration. The rate of the reaction __________ if the [CO] is doubled, with everything else kept the same. A doubles B remains unchanged C triples D increases by a factor of 4 E is reduced by a factor of 2
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5 A reaction was found to be second order in carbon monoxide concentration. The rate of the reaction __________ if the [CO] is doubled, with everything else kept the same. A doubles B remains unchanged C triples D increases by a factor of 4 E is reduced by a factor of 2
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6 If the rate law for a reaction is first order in A and second order in B, then the rate law is A k [A][B] B k[A]2[B]3 C k[A][B]2 D k[A]2[B] E k[A]2[B]2
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SLIDE 3 7 A reaction was found to be third order in A. Increasing the concentration of A by a factor of 3 will cause the reaction rate to __________. A remain constant B increase by a factor of 27 C increase by a factor of 9 D triple E decrease by a factor of the cube root of 3
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8 It was experimentally determined that the rate for the reaction (A + B ↔ P) increased by a factor of 9 when the concentration of B was tripled. The reaction is _____order in B. A zero B first C second D third E
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9 The rate law for a reaction is rate = k[A][B]2 Which
- ne of the these statements is false?
A The reaction is first order in A. B The reaction is second order in B. C The reaction is second order overall. D k is the reaction rate constant E If [B] is doubled, the reaction rate will increase by a factor of 4.
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SLIDE 4
10 The rate law of the overall reaction A+B ↔ C Is rate=k[A]2 Which of the following will not increase the rate of the reaction? A increasing the concentration of reactant A B increasing the concentration of reactant B C increasing the temperature of the reaction D adding a catalyst for the reaction E All of these will increase the rate.
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11 Which energy difference in this energy profile corresponds to the activation energy for the forward reaction? A x B y C x+y D x-y E y-x
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12 In the above drawing, what quantity is represented by the sum of x + y? A heat of reaction, DH B activation energy of the forward reaction C activation energy of the reverse reaction D potential energy of the reactants E potential energy of the products
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SLIDE 5
13 In the above drawing, what quantity is represented by “ y” ? A heat of reaction, ΔH B activation energy of the forward reaction C activation energy of the reverse reaction D potential energy of the reactants E potential energy of the products
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14 In the above drawing, what quantity is not affected by the presence of a catalyst ? A x B y C Neither x nor y D Both x and y are affected by the presence of a catalyst.
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15 In the energy profile of a reaction, the species that exists at the maximum on the curve is called the __________. A product B activated complex C activation energy D enthalpy of reaction E atomic state
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SLIDE 6 16 A catalyst can increase the rate of a reaction __________. A by lowering the activation energy of the reverse reaction B by increasing the overall activation energy (Ea )
C by providing an alternative pathway with a lower activation energy D All of these are ways that a catalyst might act to increase the rate of reaction.
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17 At equilibrium, __________. A all chemical reactions have ceased B the rates of the forward and reverse reactions are equal C the rate constants of the forward and reverse reactions are equal D the value of the equilibrium constant is 1 E the limiting reagent has been consumed
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18 Which of the following expressions is the correct equilibrium-constant expression for the reaction below? (NH4)2Se (s) ↔ 2NH3 (g) + H2Se(g) A [ NH3 ] [H2Se] / [NH4)2Se ] B [NH4)2Se ] / [ NH3 ]2 [H2Se] C 1/ [NH4)2Se ] D [ NH3 ]2 [H2Se] E [ NH3 ]2 [H2Se] / [NH4)2Se ]
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SLIDE 7 19 Which of the following expressions is the correct equilibrium-constant expression for the reaction below? HF (aq) H2O(l) ↔ H3O+ (aq) + F- (aq) A [HF][ H2O]/ [H3O+][F-] B 1/HF C [H3O+][F-] / [HF][ H2O] D [H3O+][F-] / [HF] E [F-]/[HF]
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20 The equilibrium constant for the gas phase reaction N2 (g) +3H2 (g) ↔ ( 2NH3(g) is Keq = 4.34x10-3 at
- 3000C. At equilibrium_______.
A products predominate B reactants predominate C roughly equal amounts of products and reactants are present D
E
- nly reactants are present
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21 The equilibrium constant for the gas phase reaction 2NH3(g) ↔ N2 (g) +3H2 (g) is Keq =230 at 3000C. At equilibrium, _____________ A products predominate B reactants predominate C roughly equal amounts of products and reactants are present D
E
- nly reactants are present
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SLIDE 8
22 Which of the following expressions is the correct equilibrium-constant expression for the equilibrium between dinitrogen tetroxide and nitrogen dioxide? N2O4(g)↔ 2NO2(g) A [ NO2 ] /[ N2O4 ] B [ NO2 ]2/ [ N2O4 ] C [ NO2 ]/ [ N2O4 ]2
D
[NO2][N2O4]
E [NO2]2 [N2O4]
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23 The equilibrium-constant expression for the reaction Ti(s) + 2Cl2 (g)↔TiCl4 (l) is given by A TiCl4 (l)/ [Ti(s)] + [Cl2 (g)] B [Ti(s)] [Cl2 (g)]2 / [ TiCl4 (l)] C [ TiCl4 (l)] / [Cl2 (g)]2 D [Cl2 (g)]-2 E [ TiCl4 (l)] / [Ti(s)] [Cl2 (g)]2
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24 Consider the following equilibrium. 2SO2 (g) + O2 (g)↔ 2SO3(g) The equilibrium cannot be established when __________ is/are placed in a 1.0-L container. A 0.25 mol SO2 and 0.25 mol O2 B 0.75 mol SO2 C 0.25 mol SO2 and 0.25 mol SO3 D 0.50 mol O2 and 0.50 mol SO3 E 1.0 mol SO3
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SLIDE 9
25 If the value for the equilibrium constant is much greater than 1, then the equilibrium mixture contains mostly __________. A reactants B products
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26 Pure __________ and pure __________ are excluded from equilibrium-constant expressions. A gases and compounds B solids and liquids C liquids and elements D ions and molecular compounds E Acids and bases
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27 Pure _____ and pure _____ are excluded from equilibrium-constant expressions. A gases and compounds B gases and liquids C liquids and elements D ions and molecular compounds E Acids and bases
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SLIDE 10
28 Of the following equilibria, only __________ will shift to the left in response to a decrease in volume. A H2 (g) + Cl2(g) ↔ 2HCl (g) B 2SO3(g)↔ 2SO2 (g) + O2 (g) C N2(g) + 3H2(g)↔ 2NH3(g) D 4Fe(s) + 3O2(g)↔ 2Fe2O3(s) E 2HI (g)↔ H2(g) + I2(g)
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29 The reaction below is exothermic: 2SO2 (g) + O2 (g)↔ 2SO3 (g) Le Chatelier's Principle predicts that __________ will result in an increase in the number of moles of SO3 (g) in the reaction container. A increasing the pressure B decreasing the pressure C increasing the temperature D removing some oxygen E increasing the volume of the container
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30 For the endothermic reaction CaCO3 ↔ CaO (s) + CO2 (g) Chatelier's principle predicts that __________ will result in an increase in the number of moles of CO2. A increasing the temperature B decreasing the temperature C increasing the pressure D removing some of the CaCO3 E none of the above
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SLIDE 11
31 In which of the following reactions would increasing pressure at constant temperature not change the concentrations of reactants and products, based on Le Chatelier's principle? A N2 (g) + 3H2 (g) ↔ 2NH3 (g) B N2O4 (g) ↔ 2NO2 (g) C N2(g) + 2O2 (g) ↔ 2NO2 (g) D 2N2(g) +O2 ↔ 2N2O (g) E N2 (g) +O2(g) ↔ 2NO(g)
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32 Consider the following reaction at equilibrium: 2NH3(g)↔N2(g) + 3H2(g) ΔH° = +92.4 kJ Le Chatelier's principle predicts that adding N2(g) to the system at equilibrium will result in __________. A a decrease in the concentration of NH3 B a decrease in the concentration of H2(g) C an increase in the value of the equilibrium constant D a lower partial pressure of N2 E removal of all of the H2 (g)
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33 Consider the following reaction at equilibrium: 2CO2 (g)↔ 2CO(g) + O2 (g) ΔH° = -514 kJ Le Chaelier's principle predicts that adding O2 (g) to the reaction container will __________. A increase the partial pressure of CO (g) at equilibrium B decrease the partial pressure of CO2 (g) at equilibrium C increase the value of the equilibrium constant D increase the partial pressure of CO2 (g) at equilibrium E decrease the value of the equilibrium constant
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SLIDE 12
34 Consider the following reaction at equilibrium: 2CO2 (g)↔ 2CO(g) + O2 (g) ”H° = -514 kJ Le Chatelier's principle predicts that an increase in temperature will __________. A increase the partial pressure of O2 (g) B decrease the partial pressure of CO2 (g) C decrease the value of the equilibrium constant D increase the value of the equilibrium constant E increase the partial pressure of CO
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35 Consider the following reaction at equilibrium. 2CO2 (g) ↔ 2CO(g) + O2 (g) ΔH° = -514 kJ Le Chatelier's principle predicts that the equilibrium partial pressure of CO (g) can be maximized by carrying out the reaction __________. A at high temperature and high pressure B at high temperature and low pressure C at low temperature and low pressure D at low temperature and high pressure E in the presence of solid carbon
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36 Consider the following reaction at equilibrium: 2SO2 (g) + O2(g) ↔ 2SO3 (g) ΔH° = -99 kJ Le Chatelier's principle predicts that an increase in temperature will result in __________. A a decrease in the partial pressure of SO3 B a decrease in the partial pressure of SO2 C an increase in Keq D no changes in equilibrium partial pressures E the partial pressure of O2 will decrease
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SLIDE 13
37 The effect of a catalyst on an equilibrium is to ______ A increase the rate of the forward reaction only B increase the equilibrium constant so that products are favored C slow the reverse reaction only D increase the rate at which achieved without change E shift the equilibrium to the right
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