Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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Which of the following is a measure of the average kinetic energy of the
particles in a sample of matter?
a. | chemical kinetics | c. | reaction rate | b. | thermochemistry | d. | temperature |
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2.
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In what units is temperature measured?
a. | degrees Celsius | c. | Both (a) and (b) | b. | kelvins | d. | None of the
above |
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3.
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What units are used to measure energy as heat?
a. | joules/mole or kilojoules/mole | c. | joules or
kilojoules | b. | kelvins or degrees Celsius | d. | None of the above |
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4.
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What units are used to measure specific heat?
a. | J/(g·°C) | c. | cal/(g·°C) | b. | J/(g·K) | d. | All of the
above |
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5.
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Find the specific heat of a material if a 6.0 g sample absorbs 50. J when it is
heated from 30°C to 50°C.
a. | 0.60 J | c. | 0.42 J | b. | 0.60 J/(g·°C) | d. | 0.42
J/(g·°C) |
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6.
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How much energy is absorbed as heat by 20. g of gold when it is heated from
25°C to 35°C? The specific heat of gold is 0.13 J/g·°C.
a. | 26 J | c. | 0.0006 J | b. | 26 J/(g·°C) | d. | 0.0006
J/(g·°C) |
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7.
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An equation that includes the quantity of energy released or absorbed as energy
in the form of heat during the reaction is a(n)
a. | kinetic equation. | c. | thermochemical equation. | b. | energetic
equation. | d. | temperature
equation. |
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8.
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For an exothermic reaction,  is always a. | positive. | c. | zero. | b. | negative. | d. | small. |
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9.
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For an exothermic reaction, the products
a. | are at the same energy level as the reactants. | b. | have no
energy. | c. | are at a lower energy level than the reactants. | d. | are at a higher
energy level than the reactants. |
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10.
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A compound that is very unstable and likely to decompose violently would have
a
a. | small negative enthalpy of formation. | b. | small positive enthalpy of
formation. | c. | large negative enthalpy of formation. | d. | large positive enthalpy of
formation. |
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11.
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The enthalpy of formation of compound X is –612 kJ/mol, and the sole
product of its combustion has a enthalpy of formation of –671 kJ/mol. What is the enthalpy of
combustion of compound X?
a. | –59 kJ/mol | c. | +40 kJ/mol | b. | –40 kJ/mol | d. | +59 kJ/mol |
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12.
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Two factors that determine whether a reaction will occur spontaneously are the
change in energy of a reaction system and
a. | the pressure in the system. | b. | the concentration of the reactants in the
system. | c. | the randomness of the particles in the system. | d. | the quickness of the
reaction. |
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13.
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Spontaneous reactions are driven by
a. | decreasing enthalpy and decreasing entropy. | b. | decreasing enthalpy
and increasing entropy. | c. | increasing enthalpy and decreasing
entropy. | d. | increasing enthalpy and increasing entropy. |
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14.
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As ice melts, the water molecules
a. | go from a well-ordered phase to a less-ordered phase. | b. | go from a
less-ordered phase to a more-ordered phase. | c. | stay ordered the same as in
ice. | d. | None of the above |
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15.
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Compared with a single gas, a mixture of gases is
a. | more random. | c. | equally random. | b. | less random. | d. | less favorable. |
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16.
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Which of the following is a measure of the randomness in a system?
a. | entropy | c. | free energy | b. | enthalpy | d. | temperature |
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17.
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If a process increases entropy, the process
a. | is always spontaneous. | c. | is likely to be spontaneous. | b. | is never
spontaneous. | d. | is not likely
to be spontaneous. |
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18.
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What is the symbol for entropy?
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19.
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What hinders nonspontaneous reactions?
a. | decreasing enthalpy and decreasing entropy | b. | decreasing enthalpy
and increasing entropy | c. | increasing enthalpy and decreasing
entropy | d. | increasing enthalpy and increasing entropy |
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20.
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What does DS stand for?
a. | enthalpy change | c. | entropy change | b. | free-energy change | d. | temperature
change |
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21.
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Which of the following substances has the highest entropy?
a. | steam | c. | liquid water | b. | ice water | d. | crushed ice |
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22.
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Which of the following systems has the lowest entropy?
a. | salt dissolved in a container of water | c. | oil floating in a container of
water | b. | sand mixed in a container of water | d. | a container of frozen
water |
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23.
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Which of the following has the highest entropy when produced in a
reaction?
a. | a solid | c. | a gas | b. | a liquid | d. | an aqueous
solution |
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24.
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Free-energy change depends on
a. | change of entropy only. | b. | temperature only. | c. | change of enthalpy
only. | d. | temperature and changes of entropy and enthalpy. |
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25.
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Which expression defines the change in free energy?
a. | DH + TDG | c. | DH – TDS | b. | DH +
TDS | d. | DS –
TDH |
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