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Clicker Questions

Chapter 19

Barbara Mowery

York College

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Which process is not spontaneous at 25 degrees Celsius?

a. the melting of an ice cube

b. the sublimation of dry ice

c. the boiling of liquid nitrogen

d. the freezing of ethyl alcohol

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Which process is not spontaneous at 25 degrees Celsius?

a. the melting of an ice cube

b. the sublimation of dry ice

c. the boiling of liquid nitrogen

d. the freezing of ethyl alcohol

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All spontaneous processes are

a. reversible.

b. isothermal.

c. irreversible.

d. exothermic.

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All spontaneous processes are

a. reversible.

b. isothermal.

c. irreversible.

d. exothermic.

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Entropy is a measurement of the _______ of a system.

a. randomness

b. internal energy

c. temperature

d. polarity

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Entropy is a measurement of the _______ of a system.

a. randomness

b. internal energy

c. temperature

d. polarity

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Entropy (S) is a state function, so the change in entropy is given by Sfinal _____ Sinitial.

a. +

b. −

c. ×

d. /

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Entropy (S) is a state function, so the change in entropy is given by Sfinal _____ Sinitial.

a. +

b. −

c. ×

d. /

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The entropy of a sample of CO2 increases upon heating because all three types of molecular motion increase.

a. True

b. False

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The entropy of a sample of CO2 increases upon heating because all three types of molecular motion increase.

a. True

b. False

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The entropy of a sample of Ne increases upon heating because all three types of molecular motion increase.

a. True

b. False

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The entropy of a sample of Ne increases upon heating because all three types of molecular motion increase.

a. True

b. False

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The Second Law of Thermodynamics says that the entropy of the universe _______ whenever a spontaneous process occurs.

a. increases b. decreasesc. remains unchangedd. reaches equilibrium

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The Second Law of Thermodynamics says that the entropy of the universe _______ whenever a spontaneous process occurs.

a. increases b. decreasesc. remains unchangedd. reaches equilibrium

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An automobile being driven from west to east is experiencing _______ motion.

a. kinetic

b. rotational

c. vibrational

d. translational

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An automobile being driven from west to east is experiencing _______ motion.

a. kinetic

b. rotational

c. vibrational

d. translational

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Changes in a molecule’s bond lengths or bond angles are examples of _______ motion.

a. kinetic

b. rotational

c. vibrational

d. translational

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Changes in a molecule’s bond lengths or bond angles are examples of _______ motion.

a. kinetic

b. rotational

c. vibrational

d. translational

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When a molecule spins like a top, it is undergoing _______ motion.

a. kinetic

b. vibrational

c. translational

d. rotational

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When a molecule spins like a top, it is undergoing _______ motion.

a. kinetic

b. vibrational

c. translational

d. rotational

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k = Boltzmann constant.W = the number of microstates. S = entropy.Which is true?

a. S = k × W

b. S = k / W

c. S = k ln W

d. S = kW

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k = Boltzmann constant.W = the number of microstates. S = entropy.Which is true?

a. S = k × W

b. S = k / W

c. S = k ln W

d. S = kW

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Entropy decreases when

a. a liquid becomes a gas.

b. a solid becomes a liquid.

c. a gas becomes a solid.

d. the number of moles of gas increases.

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Entropy decreases when

a. a liquid becomes a gas.

b. a solid becomes a liquid.

c. a gas becomes a solid.

d. the number of moles of gas increases.

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Which process does not illustrate a decrease in entropy?

a. Na(s) + Br2(l) 2 NaBr(s)

b. CaCO3(s) CaO(s) + CO2(g)

c. NH3(aq) +H2S(g) (NH4)2S(aq)

d. AgNO3(aq) + KCl(aq)

AgCl(s) + KNO3(aq)

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Which process does not illustrate a decrease in entropy?

a. Na(s) + Br2(l) 2 NaBr(s)

b. CaCO3(s) CaO(s) + CO2(g)

c. NH3(aq) +H2S(g) (NH4)2S(aq)

d. AgNO3(aq) + KCl(aq)

AgCl(s) + KNO3(aq)

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The Third Law of Thermodynamics says that the entropy of a pure, perfect crystal is _______ at absolute zero (zero Kelvins).

a. increasing b. decreasing

c. infinite d. zero

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The Third Law of Thermodynamics says that the entropy of a pure, perfect crystal is _______ at absolute zero (zero Kelvins).

a. increasing b. decreasing

c. infinite d. zero

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The notation, pressure, temperature, and units for reporting Standard Molar Entropies are

a. Sstd; 1 atm; 0° C; kJ/mol-°C.

b. S°; 1 atm; 298 K; J/mol-K.

c. ΔS°; 0 atm; 298 K; J/mol-K.

d. ΔS°f; 1 atm; 0° C; kJ/°C.

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The notation, pressure, temperature, and units for reporting Standard Molar Entropies are

a. Sstd; 1 atm; 0° C; kJ/mol-°C.

b. S°; 1 atm; 298 K; J/mol-K.

c. ΔS°; 0 atm; 298 K; J/mol-K.

d. ΔS°f; 1 atm; 0° C; kJ/°C.

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Which is not a standard condition for reporting Standard Free Energy values?

a. is 0 for pure liquids and solids, regardless of their state.

b. is reported for solutions at 1 M.

c. is reported for gases at 1 atm.

d. is 0 for pure elements in their standard states.

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Which is not a standard condition for reporting Standard Free Energy values?

a. is 0 for pure liquids and solids, regardless of their state.

b. is reported for solutions at 1 M.

c. is reported for gases at 1 atm.

d. is 0 for pure elements in their standard states.

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G = the Gibbs free energy.H = enthalpy. S = entropy.T = the Kelvin temperature.Which is true?

a. G = H + TS

b. G = H − TS

c. G = H × TS

d. G = H / TS

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G = the Gibbs free energy.H = enthalpy. S = entropy.T = the Kelvin temperature.Which is true?

a. G = H + TS

b. G = H − TS

c. G = H × TS

d. G = H / TS

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If the enthalpy change is positive and the entropy change is negative, the reaction is

a. spontaneous at all temperatures.

b. non-spontaneous at all temperatures.

c. spontaneous at low temperatures.

d. spontaneous at high temperatures.

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If the enthalpy change is positive and the entropy change is negative, the reaction is

a. spontaneous at all temperatures.

b. non-spontaneous at all temperatures.

c. spontaneous at low temperatures.

d. spontaneous at high temperatures.

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If the enthalpy change is negative and the entropy change is positive, the reaction is

a. spontaneous at all temperatures.

b. non-spontaneous at all temperatures.

c. spontaneous at low temperatures.

d. spontaneous at high temperatures.

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If the enthalpy change is negative and the entropy change is positive, the reaction is

a. spontaneous at all temperatures.

b. non-spontaneous at all temperatures.

c. spontaneous at low temperatures.

d. spontaneous at high temperatures.

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At equilibrium, the value of the free energy change (“delta G”) is

a. positive.

b. negative.

c. fluctuating.

d. zero.

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At equilibrium, the value of the free energy change (“delta G”) is

a. positive.

b. negative.

c. fluctuating.

d. zero.

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The general equation used to calculate ΔGrxn from standard free energies of formation is ΔGrxn =

a. ΔHrxn − T ΔSrxn.

b. Σn(ΔGf)products −Σ n(ΔGf)reactants.

c. Σn(ΔGf)reactants −Σ n(ΔGf)products.

d. ΔGf − RT lnQ.

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The general equation used to calculate ΔGrxn from standard free energies of formation is ΔGrxn =

a. ΔHrxn − T ΔSrxn.

b. Σn(ΔGf)products −Σ n(ΔGf)reactants.

c. Σn(ΔGf)reactants −Σ n(ΔGf)products.

d. ΔGf − RT lnQ.