Question 1

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 2

Identify the process that is spontaneous

Accepted Answer

A)  rusting of iron 
B)  electrolysis 
C)  photosynthesis 
D)  water flowing uphill 
E)  burning gasoline 
A)  rusting of iron 
B)  electrolysis 
C)  photosynthesis 
D)  water flowing uphill 
E)  burning gasoline

Question 3

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 4

Calculate the ΔG°rxn using the following information. 2 H2S(g)+ 3 O2(g)→ 2 SO2(g)+ 2 H2O(g)ΔG°rxn = ?
ΔH°f (kJ/mol)-20.6 -296.8 -241.8
S°(J/mol∙K)205.8 205.2 248.2 188.8

Accepted Answer

A)  -990.3 kJ 
B)  +108.2 kJ 
C)  -466.1 kJ 
D)  +676.2 kJ 
E)  -147.1 kJ 
A)  -990.3 kJ 
B)  +108.2 kJ 
C)  -466.1 kJ 
D)  +676.2 kJ 
E)  -147.1 kJ

Question 5

Identify the compound with the lowest standard free energy of formation.

Accepted Answer

A)  NaCl(s) 
B)  O2(g) 
C)  NO(g) 
D)  O3(g) 
E)  It is hard to determine. 
A)  NaCl(s) 
B)  O2(g) 
C)  NO(g) 
D)  O3(g) 
E)  It is hard to determine.

Question 6

Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. 2 Hg(g)+ O2(g)→ 2 HgO(s)ΔG° = -180.8 kJ
P(Hg)= 0.025 atm,P(O2)= 0.037 atm

Accepted Answer

A)  +207 kJ 
B)  -154.4 kJ 
C)  -26.5 kJ 
D)  -164 kJ 
E)  +60.7 kJ 
A)  +207 kJ 
B)  -154.4 kJ 
C)  -26.5 kJ 
D)  -164 kJ 
E)  +60.7 kJ

Question 7

Place the following in order of increasing molar entropy at 298 K. NO CO SO

Accepted Answer

A)  NO < CO < SO 
B)  SO < CO < NO 
C)  SO < NO < CO 
D)  CO < SO < NO 
E)  CO < NO < SO 
A)  NO < CO < SO 
B)  SO < CO < NO 
C)  SO < NO < CO 
D)  CO < SO < NO 
E)  CO < NO < SO

Question 8

Above what temperature does the following reaction become nonspontaneous?
FeO(s)+ CO(g)→ CO2(g)+ Fe(s)ΔH = -11.0 kJ; ΔS = -17.4 J/K

Accepted Answer

A)  632 K 
B)  298 K 
C)  191 K 
D)  This reaction is nonspontaneous at all temperatures. 
E)  This reaction is spontaneous at all temperatures. 
A)  632 K 
B)  298 K 
C)  191 K 
D)  This reaction is nonspontaneous at all temperatures. 
E)  This reaction is spontaneous at all temperatures.

Question 9

The ________ Law of Thermodynamics states the energy is conserved in chemical processes.

Accepted Answer

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

Question 10

Given the following equation, C3H8(g)+ 5 O2(g)→ 3 CO2(g)+ 4 H2O(g)ΔG°rxn = -2074 kJ
Calculate ΔG°rxn for the following reaction.
3 C3H8(g)+ 15 O2(g)→ 9 CO2(g)+ 12 H2O(g)

Accepted Answer

A)  -2074 kJ 
B)  + 6222 kJ 
C)  - 6222 kJ 
D)  +2074 kJ 
E)  - 691 kJ 
A)  -2074 kJ 
B)  + 6222 kJ 
C)  - 6222 kJ 
D)  +2074 kJ 
E)  - 691 kJ

Question 11

Given the following equation, C3H8(g)+ 5 O2(g)→ 3 CO2(g)+ 4 H2O(g)ΔG°rxn = -2074 kJ
Calculate ΔG°rxn for the following reaction.
12 CO2(g)+ 16 H2O(g)→ 4 C3H8(g)+ 20 O2 g)

Accepted Answer

A)  -2074 kJ 
B)  + 8296 kJ 
C)  - 8296 kJ 
D)  +2074 kJ 
E)  - 518 kJ 
A)  -2074 kJ 
B)  + 8296 kJ 
C)  - 8296 kJ 
D)  +2074 kJ 
E)  - 518 kJ

Question 12

Match between columns Premises: Q = K Q < 1 Q < K Q > 1 Q > K Q = 1

Accepted Answer

The Answer of K = 0 and ΔG < ΔG° is...

Question 13

Place the following in order of increasing standard molar entropy. H2O(l)H2O(g)H2O(s)

Accepted Answer

A)  H2O(g) 2O(l) 2O(s) 
B)  H2O(s) 2O(l) 2O(g) 
C)  H2O(g) 2O(s) 2O(l) 
D)  H2O(l) 2O(s) 2O(g) 
E)  H2O(s) 2O(g) 2O(l) 
A)  H2O(g) 2O(l) 2O(s) 
B)  H2O(s) 2O(l) 2O(g) 
C)  H2O(g) 2O(s) 2O(l) 
D)  H2O(l) 2O(s) 2O(g) 
E)  H2O(s) 2O(g) 2O(l)

Question 14

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

Accepted Answer

A)  27°C and 25 L 
B)  137°C and 25 L 
C)  27°C and 35 L 
D)  137°C and 35 L 
A)  27°C and 25 L 
B)  137°C and 25 L 
C)  27°C and 35 L 
D)  137°C and 35 L

Question 15

How is a nonspontaneous process made spontaneous?

Accepted Answer

The nonspontaneous p

Question 16

Determine the equilibrium constant for the following reaction at 298 K. N2(g)+ O2(g)→ 2 NO(g)ΔG° = 173.3 kJ

Accepted Answer

A)  5.31 × 10-15 
B)  4.19 × 10-31 
C)  6.03 × 10-6 
D)  1.32 × 10-22 
E)  2.42× 10-11 
A)  5.31 × 10-15 
B)  4.19 × 10-31 
C)  6.03 × 10-6 
D)  1.32 × 10-22 
E)  2.42× 10-11

Question 17

Above what temperature does the following reaction become nonspontaneous?
N2(s)+ 3 H2(g)→ 2 NH3(g)ΔH = -92.22 kJ; ΔS = -198.75 J/K

Accepted Answer

A)  186 K 
B)  326 K 
C)  464 K 
D)  This reaction is nonspontaneous at all temperatures. 
E)  This reaction is spontaneous at all temperatures. 
A)  186 K 
B)  326 K 
C)  464 K 
D)  This reaction is nonspontaneous at all temperatures. 
E)  This reaction is spontaneous at all temperatures.

Question 18

Which one of the following has the highest standard molar entropy,S°,at 25°C?

Accepted Answer

A)  I2(g) 
B)  F2(g) 
C)  Br2(l) 
D)  H2(g) 
E)  Cl2(g) 
A)  I2(g) 
B)  F2(g) 
C)  Br2(l) 
D)  H2(g) 
E)  Cl2(g)

Question 19

Estimate ΔG°rxn for the following reaction at 875 K. 2 Hg(g)+ O2(g)→ 2 HgO(s)ΔH°= -304.2 kJ; ΔS°= -414.2 J/K

Accepted Answer

A)  -2.63 kJ 
B)  - 58.0 kJ 
C)  + 58.0 kJ 
D)  + 666 kJ 
E)  - 666 kJ 
A)  -2.63 kJ 
B)  - 58.0 kJ 
C)  + 58.0 kJ 
D)  + 666 kJ 
E)  - 666 kJ

Question 20

Identify the change in state that does not have an increase in entropy.

Accepted Answer

A)  gasoline freezing 
B)  water boiling 
C)  ice melting 
D)  dry ice subliming 
E)  water evaporating 
A)  gasoline freezing 
B)  water boiling 
C)  ice melting 
D)  dry ice subliming 
E)  water evaporating

Exam 19: Free Energy and Thermodynamics

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

Identify the process that is spontaneous

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

Calculate the ΔG°rxn using the following information. 2 H2S(g)+ 3 O2(g)→ 2 SO2(g)+ 2 H2O(g)ΔG°rxn = ? ΔH°f (kJ/mol)-20.6 -296.8 -241.8 S°(J/mol∙K)205.8 205.2 248.2 188.8

Identify the compound with the lowest standard free energy of formation.

Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. 2 Hg(g)+ O2(g)→ 2 HgO(s)ΔG° = -180.8 kJ P(Hg)= 0.025 atm,P(O2)= 0.037 atm

Place the following in order of increasing molar entropy at 298 K. NO CO SO

Above what temperature does the following reaction become nonspontaneous? FeO(s)+ CO(g)→ CO2(g)+ Fe(s)ΔH = -11.0 kJ; ΔS = -17.4 J/K

The ________ Law of Thermodynamics states the energy is conserved in chemical processes.

Given the following equation, C3H8(g)+ 5 O2(g)→ 3 CO2(g)+ 4 H2O(g)ΔG°rxn = -2074 kJ Calculate ΔG°rxn for the following reaction. 3 C3H8(g)+ 15 O2(g)→ 9 CO2(g)+ 12 H2O(g)

Given the following equation, C3H8(g)+ 5 O2(g)→ 3 CO2(g)+ 4 H2O(g)ΔG°rxn = -2074 kJ Calculate ΔG°rxn for the following reaction. 12 CO2(g)+ 16 H2O(g)→ 4 C3H8(g)+ 20 O2 g)

Place the following in order of increasing standard molar entropy. H2O(l)H2O(g)H2O(s)

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

How is a nonspontaneous process made spontaneous?

Determine the equilibrium constant for the following reaction at 298 K. N2(g)+ O2(g)→ 2 NO(g)ΔG° = 173.3 kJ

Above what temperature does the following reaction become nonspontaneous? N2(s)+ 3 H2(g)→ 2 NH3(g)ΔH = -92.22 kJ; ΔS = -198.75 J/K

Which one of the following has the highest standard molar entropy,S°,at 25°C?

Estimate ΔG°rxn for the following reaction at 875 K. 2 Hg(g)+ O2(g)→ 2 HgO(s)ΔH°= -304.2 kJ; ΔS°= -414.2 J/K

Identify the change in state that does not have an increase in entropy.

Essentials: Units, Measurements, and Problem Solving

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The Quantum Mechanical Model of the Atom

Periodic Properties of the Elements

Molecules and Compounds

Chemical Bonding I

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Chemical Reactions and Chemical Quantities

Introduction to Solutions and Aqueous Reactions

Thermochemistry

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Liquids, Solids, and Intermolecular Forces

Crystalline Solids and Modern Materials

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Chemical Kinetics

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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

Calculate the ΔG°_rxn using the following information. 2 H₂S(g)+ 3 O₂(g)→ 2 SO₂(g)+ 2 H₂O(g)ΔG°_rxn= ? ΔH°_f (kJ/mol)-20.6 -296.8 -241.8 S°(J/mol^∙K)205.8 205.2 248.2 188.8

Calculate ΔG_rxn at 298 K under the conditions shown below for the following reaction. 2 Hg(g)+ O₂(g)→ 2 HgO(s)ΔG° = -180.8 kJ P(Hg)= 0.025 atm,P(O₂)= 0.037 atm

Above what temperature does the following reaction become nonspontaneous? FeO(s)+ CO(g)→ CO₂(g)+ Fe(s)ΔH = -11.0 kJ; ΔS = -17.4 J/K

Given the following equation, C₃H₈(g)+ 5 O₂(g)→ 3 CO₂(g)+ 4 H₂O(g)ΔG°_rxn = -2074 kJ Calculate ΔG°_rxn for the following reaction. 3 C₃H₈(g)+ 15 O₂(g)→ 9 CO₂(g)+ 12 H₂O(g)

Given the following equation, C₃H₈(g)+ 5 O₂(g)→ 3 CO₂(g)+ 4 H₂O(g)ΔG°_rxn = -2074 kJ Calculate ΔG°_rxn for the following reaction. 12 CO₂(g)+ 16 H₂O(g)→ 4 C₃H₈(g)+ 20 O₂ g)

Place the following in order of increasing standard molar entropy. H₂O(l)H₂O(g)H₂O(s)

Determine the equilibrium constant for the following reaction at 298 K. N₂(g)+ O₂(g)→ 2 NO(g)ΔG° = 173.3 kJ

Above what temperature does the following reaction become nonspontaneous? N₂(s)+ 3 H₂(g)→ 2 NH₃(g)ΔH = -92.22 kJ; ΔS = -198.75 J/K

Estimate ΔG°_rxn for the following reaction at 875 K. 2 Hg(g)+ O₂(g)→ 2 HgO(s)ΔH°= -304.2 kJ; ΔS°= -414.2 J/K