Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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In the reaction represented by the following equation, a possible intermediate
is H 2( g) + I 2( g)  2HI( g)
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2.
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How many steps are in the pathway when hydrogen iodide forms from its
elements?
a. | one | c. | four or five | b. | two or three | d. | five or six |
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3.
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Which attempts to explain chemical reactions and physical interactions of
molecules?
a. | chemical kinetics | c. | thermodynamics | b. | collision theory | d. | thermochemistry |
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4.
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Activation energy is
a. | the energy required to form the activated complex. | b. | the net energy
required to turn reactants into products. | c. | the enthalpy of reaction. | d. | free
energy. |
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5.
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The bonding of the activated complex is characteristic of
a. | reactants only. | c. | both reactants and products. | b. | products
only. | d. | solids
only. |
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6.
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An activated complex
a. | always separates into the products. | b. | always re-forms the
reactants. | c. | may either separate into the products or re-form the reactants. | d. | always
evaporates. |
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7.
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What takes place in an activated complex?
a. | Bonds form. | b. | Bonds break. | c. | Some bonds form and
other bonds break. | d. | A catalyst is
produced. |
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8.
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Which statement correctly describes the energy changes that occur when bonds
form and when bonds break?
a. | Breaking bonds is endothermic, and forming bonds is exothermic. | b. | Breaking bonds is
exothermic, and forming bonds is endothermic. | c. | Both are exothermic. | d. | Both are
endothermic. |
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9.
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 is positive for a. | an endothermic reaction. | c. | an inhibited
reaction. | b. | an exothermic reaction. | d. | a stable reaction. |
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10.
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Which term has the same numerical value for the forward reaction as it has for
the reverse reaction but with opposite sign?
a. | DE | c. | Ea´ | b. |  | d. | Ea |
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11.
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The usual condition for reaction, a favorable orientation, is not necessary
for
a. | synthesis reactions. | c. | single-displacement reactions. | b. | decomposition
reactions. | d. | double-displacement reactions. |
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12.
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Chemical kinetics studies
a. | the factors that affect the rate of reaction. | b. | the mathematical
expressions for the rate of reaction. | c. | the factors that affect the rate of reaction
and the mathematical expressions for the rate of reaction. | d. | the effect of
quantum kinetics on chemical reactions. |
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13.
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The study of chemical kinetics requires concentrations that are measured
a. | once. | c. | using a scale. | b. | in meters/second. | d. | frequently. |
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14.
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How fast something changes with time is a(n)
a. | area. | c. | order. | b. | rate. | d. | collision. |
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15.
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Reaction rate depends upon
a. | both collision frequency and efficiency. | b. | average kinetic
energy. | c. | collision efficiency. | d. | average potential
energy. |
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16.
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Which of the following affects reaction rate?
a. | the nature of reactants | c. | temperature | b. | surface area of
reactants | d. | All of the
above |
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17.
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Which of the following burns most slowly?
a. | a large lump of coal | c. | powdered coal | b. | small pieces of coal | d. | All of these burn at the same
rate. |
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18.
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If the surface area of reactants is larger,
a. | the reaction rate is generally higher. | c. | the reaction rate is not
affected. | b. | the reaction rate is generally lower. | d. | the rate-determining step is
eliminated. |
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19.
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Doubling the pressure of a gas
a. | increases the concentration by a factor of two. | b. | reduces the
concentration by a factor of two. | c. | doesn't affect the
concentration. | d. | reduces the concentration by a factor of four. |
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20.
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Which term describes a catalyst in the same phase as the reactants and
products?
a. | homogenous | c. | activated | b. | heterogeneous | d. | inhibited |
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21.
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According to the rate law, the rate of a reaction and the concentration of
reactants are always
a. | equal. | c. | negative. | b. | proportional. | d. | unable to be
determined. |
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22.
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Rate laws are determined by
a. | studying reaction mechanisms. | b. | calculating kinetic energy, frequency of
collision, and temperature for a reaction. | c. | applying collision theory to a
reaction. | d. | experiment. |
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23.
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If doubling the concentration of a reactant doubles the rate of the reaction,
the concentration of the reactant appears in the rate law with a(n)
a. | exponent of 1. | c. | exponent of 4. | b. | exponent of 2. | d. | coefficient of
2. |
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24.
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If doubling the concentration of a reactant quadruples the rate of the reaction,
the concentration of the reactant appears in the rate law with a(n)
a. | exponent of 1. | c. | exponent of 4. | b. | exponent of 2. | d. | coefficient of
2. |
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25.
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If a chemical reaction proceeds in a sequence of steps, the slowest step is
called
a. | the kinetic step. | c. | the problem step. | b. | the constant step. | d. | the rate-determining
step. |
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