Question 1

Identify the compound with the standard free energy of formation equal to zero.

Accepted Answer

A)  NaI(s) 
B)  H2(g) 
C)  NO(g) 
D)  O3(g) 
E)  It is hard to determine. 
A)  NaI(s) 
B)  H2(g) 
C)  NO(g) 
D)  O3(g) 
E)  It is hard to determine.

Question 2

For the following example,identify the following. I2(l)→ I2(g)

Accepted Answer

A)  a negative ΔH and a negative ΔS 
B)  a positive ΔH and a negative ΔS 
C)  a negative ΔH and a positive ΔS 
D)  a positive ΔH and a positive ΔS 
E)  It is not possible to determine without more information. 
A)  a negative ΔH and a negative ΔS 
B)  a positive ΔH and a negative ΔS 
C)  a negative ΔH and a positive ΔS 
D)  a positive ΔH and a positive ΔS 
E)  It is not possible to determine without more information.

Question 3

Given the following equation, H2O(g)+ CO(g)→ H2(g)+ CO2(g)ΔG°rxn = -28.6 kJ
Calculate ΔG°rxn for the following reaction.
8 H2O(g)+ 8 CO(g)→ 8 H2(g)+ 8 CO2(g)

Accepted Answer

A)  -228.8 kJ 
B)  +228.8 kJ 
C)  -3.57 kJ 
D)  +3.57 kJ 
E)  -28.6 kJ 
A)  -228.8 kJ 
B)  +228.8 kJ 
C)  -3.57 kJ 
D)  +3.57 kJ 
E)  -28.6 kJ

Question 4

Why can endothermic reactions be spontaneous?

Accepted Answer

Even though an endothermic process requi

Question 5

Identify the element with the highest standard free energy of formation.

Accepted Answer

A)  Ba(s) 
B)  Ca(s) 
C)  Li(s) 
D)  K(s) 
E)  All elements have a value of zero. 
A)  Ba(s) 
B)  Ca(s) 
C)  Li(s) 
D)  K(s) 
E)  All elements have a value of zero.

Question 6

Under which of the following conditions would one mole of Ar have the highest entropy,S?

Accepted Answer

A)  57°C and 55 L 
B)  90°C and 15 L 
C)  17°C and 30 L 
D)  167°C and 101 L 
A)  57°C and 55 L 
B)  90°C and 15 L 
C)  17°C and 30 L 
D)  167°C and 101 L

Question 7

The value of ΔG° at 141.0°C for the formation of phosphorous trichloride from its constituent elements, P2(g)+ 3 Cl2(g)→ 2 PCl3(g)
Is ________ kJ/mol.At 25.0°C for this reaction,ΔH° is -720.5 kJ/mol,ΔG° is -642.9 kJ/mol,and ΔS° is -263.7 J/K.

Accepted Answer

A)  -612.3 
B)  3.65 × 104 
C)  1.08 × 105 
D)  -683.3 
E)  -829.7 
A)  -612.3 
B)  3.65 × 104 
C)  1.08 × 105 
D)  -683.3 
E)  -829.7

Question 8

In which of the following processes do the molecules become more orderly?

Accepted Answer

A)  water freezing 
B)  ice melting 
C)  ethanol evaporating 
D)  salt dissolving in water 
E)  dry ice subliming 
A)  water freezing 
B)  ice melting 
C)  ethanol evaporating 
D)  salt dissolving in water 
E)  dry ice subliming

Question 9

Identify the process in which the entropy increases.

Accepted Answer

A)  a decrease in the number of moles of a gas during a chemical reaction 
B)  the phase transition from a gas to a liquid 
C)  the phase transition from a solid to a gas 
D)  the phase transition from a gas to a solid 
E)  the phase transition from a liquid to a solid 
A)  a decrease in the number of moles of a gas during a chemical reaction 
B)  the phase transition from a gas to a liquid 
C)  the phase transition from a solid to a gas 
D)  the phase transition from a gas to a solid 
E)  the phase transition from a liquid to a solid

Question 10

Identify a process that is NOT reversible.

Accepted Answer

A)  melting of steel 
B)  freezing water 
C)  melting of ice 
D)  frying an egg 
E)  deposition of carbon dioxide 
A)  melting of steel 
B)  freezing water 
C)  melting of ice 
D)  frying an egg 
E)  deposition of carbon dioxide

Question 11

Use Hess's law to calculate ΔG°rxn using the following information. CO(g)→ C(s)+ 1/2 O2(g)ΔG°rxn = ?
CO2(g)→ C(s)+ O2(g)ΔG°rxn = +394.4 kJ
CO(g)+ 1/2 O2(g)→ CO2(g)ΔG°rxn = -257.2 kJ

Accepted Answer

A)  -60.0 kJ 
B)  +651.6 kJ 
C)  +265.8 kJ 
D)  +137.2 kJ 
E)  -137.2 kJ 
A)  -60.0 kJ 
B)  +651.6 kJ 
C)  +265.8 kJ 
D)  +137.2 kJ 
E)  -137.2 kJ

Question 12

Determine ΔG°rxn for the following reaction at 358 K. CaCO3(s)→ CaO(s)+ CO2(g)ΔH°= +179.2 kJ; DS°= +160.2 J/K

Accepted Answer

A)  +179.2 kJ 
B)  +236.6 kJ 
C)  -236.6 kJ 
D)  +121.8 kJ 
E)  -121.8 kJ 
A)  +179.2 kJ 
B)  +236.6 kJ 
C)  -236.6 kJ 
D)  +121.8 kJ 
E)  -121.8 kJ

Question 13

Why is heating your home with gas more efficient than heating it with electricity?

Accepted Answer

Heating with gas only requires a one-ste

Question 14

Consider the following reaction at constant P.Use the information here to determine the value of ΔSsurr at 398 K.Predict whether or not this reaction will be spontaneous at this temperature. 4 NH3(g)+ 3 O2(g)→ 2 N2(g)+ 6 H2O(g)ΔH = -1267 kJ

Accepted Answer

A)  ΔSsurr = +12.67 kJ/K, reaction is not spontaneous 
B)  ΔSsurr = -12.67 kJ/K, reaction is spontaneous 
C)  ΔSsurr = +50.4 kJ/K, reaction is not spontaneous 
D)  ΔSsurr = +3.18 kJ/K, reaction is spontaneous 
E)  ΔSsurr = -50.4 kJ/K, it is not possible to predict the spontaneity of this reaction without more information. 
A)  ΔSsurr = +12.67 kJ/K, reaction is not spontaneous 
B)  ΔSsurr = -12.67 kJ/K, reaction is spontaneous 
C)  ΔSsurr = +50.4 kJ/K, reaction is not spontaneous 
D)  ΔSsurr = +3.18 kJ/K, reaction is spontaneous 
E)  ΔSsurr = -50.4 kJ/K, it is not possible to predict the spontaneity of this reaction without more information.

Question 15

Place the following in order of decreasing standard molar entropy. N2O4(g)NO(g)NO2(g)

Accepted Answer

A)  N2O4  > NO2  > NO 
B)  NO > NO2 > N2O4 
C)  N2O4  > NO > NO2 
D)  NO > N2O4  > NO2 
E)  NO2 > NO > N2O4 
A)  N2O4  > NO2  > NO 
B)  NO > NO2 > N2O4 
C)  N2O4  > NO > NO2 
D)  NO > N2O4  > NO2 
E)  NO2 > NO > N2O4

Question 16

The ________ Law of Thermodynamics states that for any spontaneous reaction,the entropy of the universe increases.

Accepted Answer

A)  Zero 
B)  First 
C)  Second 
D)  Third 
E)  Fourth 
A)  Zero 
B)  First 
C)  Second 
D)  Third 
E)  Fourth

Question 17

Give the standard states for a gas,liquid,solid,and solution.

Accepted Answer

For a gas - 1 atm; for a liqui

Question 18

Which of the following statements is TRUE?

Accepted Answer

A)  Entropy is not a state function. 
B)  Endothermic processes decrease the entropy of the surroundings, at constant T and P. 
C)  Endothermic processes are never spontaneous. 
D)  Exothermic processes are always spontaneous. 
E)  None of the above is true. 
A)  Entropy is not a state function. 
B)  Endothermic processes decrease the entropy of the surroundings, at constant T and P. 
C)  Endothermic processes are never spontaneous. 
D)  Exothermic processes are always spontaneous. 
E)  None of the above is true.

Question 19

Use the free energies of formation given below to calculate the equilibrium constant (K)for the following reaction at 298 K. 2 HNO3(aq)+ NO(g)→ 3 NO2(g)+ H2O(l)K = ?
ΔG°f (kJ/mol)-110.9 87.6 51.3 -237.1

Accepted Answer

A)  8.71 × 108 
B)  0.980 
C)  1.15 × 10-9 
D)  1.02 
E)  5.11 × 10-4 
A)  8.71 × 108 
B)  0.980 
C)  1.15 × 10-9 
D)  1.02 
E)  5.11 × 10-4

Question 20

For the following example,identify the following. 2 F2(g)+ O2(g)→ 2 F2O(g)

Accepted Answer

A)  at low temperature, the reaction is spontaneous and ΔG  0 and at high temperature, the reaction is spontaneous and ΔG  0 
D)  at low temperature, the reaction is nonspontaneous and ΔG > 0 and at high temperature, the reaction is nonspontaneous and ΔG > 0 
E)  It is not possible to determine without more information. 
A)  at low temperature, the reaction is spontaneous and ΔG  0 and at high temperature, the reaction is spontaneous and ΔG  0 
D)  at low temperature, the reaction is nonspontaneous and ΔG > 0 and at high temperature, the reaction is nonspontaneous and ΔG > 0 
E)  It is not possible to determine without more information.

Exam 18: Free Energy and Thermodynamics

Identify the compound with the standard free energy of formation equal to zero.

For the following example,identify the following. I2(l)→ I2(g)

Given the following equation, H2O(g)+ CO(g)→ H2(g)+ CO2(g)ΔG°rxn = -28.6 kJ Calculate ΔG°rxn for the following reaction. 8 H2O(g)+ 8 CO(g)→ 8 H2(g)+ 8 CO2(g)

Why can endothermic reactions be spontaneous?

Identify the element with the highest standard free energy of formation.

Under which of the following conditions would one mole of Ar have the highest entropy,S?

The value of ΔG° at 141.0°C for the formation of phosphorous trichloride from its constituent elements, P2(g)+ 3 Cl2(g)→ 2 PCl3(g) Is ________ kJ/mol.At 25.0°C for this reaction,ΔH° is -720.5 kJ/mol,ΔG° is -642.9 kJ/mol,and ΔS° is -263.7 J/K.

In which of the following processes do the molecules become more orderly?

Identify the process in which the entropy increases.

Identify a process that is NOT reversible.

Use Hess's law to calculate ΔG°rxn using the following information. CO(g)→ C(s)+ 1/2 O2(g)ΔG°rxn = ? CO2(g)→ C(s)+ O2(g)ΔG°rxn = +394.4 kJ CO(g)+ 1/2 O2(g)→ CO2(g)ΔG°rxn = -257.2 kJ

Determine ΔG°rxn for the following reaction at 358 K. CaCO3(s)→ CaO(s)+ CO2(g)ΔH°= +179.2 kJ; DS°= +160.2 J/K

Why is heating your home with gas more efficient than heating it with electricity?

Consider the following reaction at constant P.Use the information here to determine the value of ΔSsurr at 398 K.Predict whether or not this reaction will be spontaneous at this temperature. 4 NH3(g)+ 3 O2(g)→ 2 N2(g)+ 6 H2O(g)ΔH = -1267 kJ

Place the following in order of decreasing standard molar entropy. N2O4(g)NO(g)NO2(g)

The ________ Law of Thermodynamics states that for any spontaneous reaction,the entropy of the universe increases.

Give the standard states for a gas,liquid,solid,and solution.

Which of the following statements is TRUE?

Use the free energies of formation given below to calculate the equilibrium constant (K)for the following reaction at 298 K. 2 HNO3(aq)+ NO(g)→ 3 NO2(g)+ H2O(l)K = ? ΔG°f (kJ/mol)-110.9 87.6 51.3 -237.1

For the following example,identify the following. 2 F2(g)+ O2(g)→ 2 F2O(g)

Matter, measurement, and Problem Solving

Atoms and Elements

Molecules,compounds,and Chemical Equations

Chemical Quantities and Aqueous Reactions

Gases

Thermochemistry

The Quantum-Mechanical Model of the Atom

Periodic Properties of the Elements

Chemical Bonding I: Lewis Theory

Chemical Bonding Ii: Molecular Shapes,valence Bond Theory,

Liquids,solids,and Intermolecular Forces

Solids and Modern Materials

Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Aqueous Ionic Equilibrium

Electrochemistry

Radioactivity and Nuclear Chemistry

Organic Chemistry

Biochemistry

Chemistry of the Nonmetals

Metals and Metallurgy

Transition Metals and Coordination Compounds

Filters

For the following example,identify the following. I₂(l)→ I₂(g)

Given the following equation, H₂O(g)+ CO(g)→ H₂(g)+ CO₂(g)ΔG°_rxn = -28.6 kJ Calculate ΔG°_rxn for the following reaction. 8 H₂O(g)+ 8 CO(g)→ 8 H₂(g)+ 8 CO₂(g)

The value of ΔG° at 141.0°C for the formation of phosphorous trichloride from its constituent elements, P₂(g)+ 3 Cl₂(g)→ 2 PCl₃(g) Is ________ kJ/mol.At 25.0°C for this reaction,ΔH° is -720.5 kJ/mol,ΔG° is -642.9 kJ/mol,and ΔS° is -263.7 J/K.

Use Hess's law to calculate ΔG°_rxn using the following information. CO(g)→ C(s)+ 1/2 O₂(g)ΔG°_rxn= ? CO₂(g)→ C(s)+ O₂(g)ΔG°_rxn= +394.4 kJ CO(g)+ 1/2 O₂(g)→ CO₂(g)ΔG°_rxn= -257.2 kJ

Determine ΔG°_rxn for the following reaction at 358 K. CaCO₃(s)→ CaO(s)+ CO₂(g)ΔH°= +179.2 kJ; DS°= +160.2 J/K

Consider the following reaction at constant P.Use the information here to determine the value of ΔS_surr at 398 K.Predict whether or not this reaction will be spontaneous at this temperature. 4 NH₃(g)+ 3 O₂(g)→ 2 N₂(g)+ 6 H₂O(g)ΔH = -1267 kJ

Place the following in order of decreasing standard molar entropy. N₂O₄(g)NO(g)NO₂(g)

Use the free energies of formation given below to calculate the equilibrium constant (K)for the following reaction at 298 K. 2 HNO₃(aq)+ NO(g)→ 3 NO₂(g)+ H₂O(l)K= ? ΔG°_f (kJ/mol)-110.9 87.6 51.3 -237.1

For the following example,identify the following. 2 F₂(g)+ O₂(g)→ 2 F₂O(g)