Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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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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2.
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How is a Celsius temperature reading converted to a Kelvin temperature
reading?
a. | by adding 273.15 | c. | by dividing by 273.15 | b. | by subtracting
273.15 | d. | by multiplying by
273.15 |
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3.
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Energy absorbed or released as heat in a chemical or physical change is measured
by a(n)
a. | thermometer. | c. | incubator. | b. | scale. | d. | calorimeter. |
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4.
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If a piece of aluminum is heated from 30.0  C to 50.0  C, what is the value of  ? a. | 0.0K | b. | 20.0K | c. | 293.0K | d. | Cannot be determined from the information
given |
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5.
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A 4.0 g sample of iron was heated from 0°C to 20.°C. It absorbed 35.2
J of energy as heat. What is the specific heat of this piece of iron?
a. | 2816 J/(g·°C) | c. | 2.27 J/g | b. | 2.27
J/(g·°C) | d. | 0.44
J/(g·°C) |
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6.
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How much energy does a copper sample absorb as energy in the form of heat if its
specific heat is 0.384 J/(g·°C), its mass is 8.00 g, and it is heated from 10.0°C to
40.0°C?
a. | 0.0016 J/(g·°C) | c. | 92.2 J | b. | 0.0016
J | d. | 92.2
J/(g·°C) |
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7.
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What is the difference between the enthalpies of the products and the
reactants?
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8.
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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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9.
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For an exothermic reaction,  is always a. | positive. | c. | zero. | b. | negative. | d. | small. |
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10.
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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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11.
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DH =
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12.
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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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13.
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The enthalpy of a reaction for a chemical change can be determined by
a. | multiplying the total enthalpies of the products and reactants. | b. | subtracting the
total enthalpies of the reactants from that of the products. | c. | subtracting the
total enthalpy of the products from that of the reactants. | d. | adding the total
enthalpies of the products and reactants. |
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Use the tables below to answer the following questions.
Enthalpies of Formation (kJ/mol) | | Enthalpies of Combustion (kJ/mol) | | Substance | Formula | DH0f | | Substance | Formula | DH0c | | ammonia(s) | NH3 | –45.9 | | hydrogen(g) | H2 | –285.8 | | barium
nitrate(s) | Ba(NO3)2 | –992.1 | | carbon (graphite)(s) | C | –393.5 | | benzene(l) | C6H6 | +49.1 | | carbon monoxide (g) | CO | –283.0 | | calcium chloride(s) | CaCl2 | –795.4 | | methane (g) | CH4 | –890.8 | | carbon (diamond)
(s) | C | +1.9 | | ethane(g) | C2H6 | –1560.7 | | carbon (graphite)(s) | C | 0.0 | | propane(g) | C3H8 | –2219.2 | | carbon dioxide(g) | CO2 | –393.5 | | butane(g) | C4H10 | –2877.6 | | copper(II) sulfate(s) | CuSO4 | –771.4 | | pentane(g) | C5H12 | –3535.6 | | ethyne (acetylene)(g) | C2H2 | +228.2 | | hexane(l) | C6H14 | –4163.2 | | hydrogen chloride(g) | HCl | –92.3 | | heptane(l) | C7H16 | –4817.0 | | water(l) | H2O | –285.8 | | octane(l) | C8H18 | –5470.5 | | nitrogen dioxide(g) | NO2 | +33.2 | | ethene
(ethylene)(g) | C2H4 | –1411.2 | | ozone(g) | O3 | +142.7 | | propene
(propylene)(g) | C3H6 | –2058.0 | | sodium chloride(s) | NaCl | –385.9 | | ethyne
(acetylene)(g) | C2H2 | –1301.1 | | sulfur dioxide(g) | SO2 | –296.8 | | benzene(l) | C6H6 | –3267.6 | | zinc sulfate(s) | ZnSO4 | –980.1 | | toluene(l) | C7H8 | –3910.3 | | | | | | | |
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14.
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What is the enthalpy of combustion of 1 mol of sulfur to form
SO2?
a. | –593.6 kJ/mol | c. | 0 kJ/mol | b. | –296.8 kJ/mol | d. | +296.8 kJ/mol |
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15.
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Ice melting is an example of a(n)
a. | exothermic reaction. | c. | endothermic reaction. | b. | negative entropic
reactions. | d. | catalysed
reaction. |
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16.
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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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17.
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The entropy of a system is reported in units of
a. | kJ. | c. | kJ/mol. | b. | kJ/(g·K). | d. | kJ/(mol·K). |
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18.
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Entropy in a system increases when
a. | gases are diluted. | b. | ions disperse in a
solution. | c. | the total moles of gaseous product exceed the total moles of gaseous
reactant. | d. | All of the above |
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19.
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Entropy decreases when
a. | pressure decreases. | c. | the system is agitated. | b. | temperature
decreases. | d. | temperature
increases. |
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20.
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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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21.
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The driving force of a reaction is the change in
a. | free energy. | c. | enthalpy. | b. | entropy. | d. | temperature. |
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22.
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What is the symbol for free-energy change?
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23.
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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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24.
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The units for  are a. | J/(mol·K). | c. | J/(mol·C). | b. | joules. | d. | J/mol. |
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25.
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What quantity predicts whether a reaction is spontaneous?
a. | enthalpy | c. | temperature | b. | free energy | d. | entropy |
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