Question 1

Match the following.
-Q = K

Accepted Answer

A) ΔG  0 
D) ΔG  ΔG° 
A) ΔG  0 
D) ΔG  ΔG°

Question 2

Which of the following statements is true?

Accepted Answer

A) Entropy is an extensive property. 
B) Entropy is not temperature dependent. 
C) Exothermic processes decrease the entropy of the surroundings. 
D) ΔSuniverse is always greater than zero for a nonspontaneous process. 
E) None of the above are true. 
A) Entropy is an extensive property. 
B) Entropy is not temperature dependent. 
C) Exothermic processes decrease the entropy of the surroundings. 
D) ΔSuniverse is always greater than zero for a nonspontaneous process. 
E) None of the above are true.

Question 3

Calculate ΔS°rxn for the following reaction.The S° for each species is shown below the reaction.
P4(g)+ 10 Cl2(g)→ 4 PCl5(g)
S°(J/mol∙K)280.0 223.1 364.6

Accepted Answer

A) -138.5 J/K 
B) -1052.6 J/K 
C) +171.3 J/K 
D) -583.6 J/K 
E) +2334.6 J/K 
A) -138.5 J/K 
B) -1052.6 J/K 
C) +171.3 J/K 
D) -583.6 J/K 
E) +2334.6 J/K

Question 4

Determine the equilibrium constant for the following reaction at 655 K.
HCN(g)+ 2 H2(g)→ CH3NH2(g)ΔH° = -158 kJ;ΔS°= -219.9 J/K

Accepted Answer

A) 3.99 × 1012 
B) 13.0 
C) 2.51 × 10-13 
D) 3.26 × 10-12 
E) 3.07 × 1011 
A) 3.99 × 1012 
B) 13.0 
C) 2.51 × 10-13 
D) 3.26 × 10-12 
E) 3.07 × 1011

Question 5

Determine the equilibrium constant for the following reaction at 549 K.
CH2O(g)+ 2 H2(g)→ CH4(g)+ H2O(g)
ΔH° = -94.9 kJ;ΔS° = -224.2 J/K

Accepted Answer

A) 481 
B) 1.07 × 109 
C) 2.08 × 10-3 
D) 9.35 × 10-10 
E) 1.94 × 10-12 
A) 481 
B) 1.07 × 109 
C) 2.08 × 10-3 
D) 9.35 × 10-10 
E) 1.94 × 10-12

Question 6

Which of the following processes has a ΔS < 0?

Accepted Answer

A) Water freezes. 
B) Isopropyl alcohol condenses. 
C) methanol (g,at 555 K)→ methanol (g,at 400 K) 
D) carbon dioxide(g)→ carbon dioxide(s) 
E) All of the above processes have a ΔS < 0. 
A) Water freezes. 
B) Isopropyl alcohol condenses. 
C) methanol (g,at 555 K)→ methanol (g,at 400 K) 
D) carbon dioxide(g)→ carbon dioxide(s) 
E) All of the above processes have a ΔS < 0.

Question 7

Identify the compound that is not an allotrope of carbon.

Accepted Answer

A) diamond 
B) dry ice 
C) graphite 
D) charcoal 
E) buckyball 
A) diamond 
B) dry ice 
C) graphite 
D) charcoal 
E) buckyball

Question 8

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) +523.0 kJ 
A) -60.0 kJ 
B) +651.6 kJ 
C) -265.8 kJ 
D) +137.2 kJ 
E) +523.0 kJ

Question 9

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

Accepted Answer

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

Question 10

The value of ΔG° at 100.0 °C for the formation of calcium chloride from its constituent elements:
Ca(s)+ Cl2(g)→ CaCl2(s)
Is ________ kJ/mol.At 25.0°C for this reaction,ΔH° is -795.8 kJ/mol,ΔG° is -748.1 kJ/mol,and ΔS° is
-159.8 J/K.

Accepted Answer

A) -855.4 
B) -736.1 
C) 5.88 × 104 
D) -779.8 
E) 1.52 × 104 
A) -855.4 
B) -736.1 
C) 5.88 × 104 
D) -779.8 
E) 1.52 × 104

Question 11

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

Accepted Answer

A) 17°C and 15 L 
B) 127°C and 15 L 
C) 17°C and 25 L 
D) 127°C and 25 L 
A) 17°C and 15 L 
B) 127°C and 15 L 
C) 17°C and 25 L 
D) 127°C and 25 L

Question 12

Estimate ΔG°rxn for the following reaction at 775 K.
2 Hg(g)+ O2(g)→ 2 HgO(s)ΔH° = -304.2 kJ;ΔS° = -414.2 J/K

Accepted Answer

A) -625 kJ 
B) -181 kJ 
C) +17 kJ 
D) +321 kJ 
E) -110 kJ 
A) -625 kJ 
B) -181 kJ 
C) +17 kJ 
D) +321 kJ 
E) -110 kJ

Question 13

Phosphorous and chlorine gases combine to produce phosphorous trichloride:
P2(g)+ 3Cl2(g)→ 2PCl3(g)
ΔG° at 298 K for this reaction is -642.9 kJ/mol.The value of ΔG at 298 K for a reaction mixture that consists of 1.5 atm P2,1.6 atm Cl2,and 0.65 atm PCl3 is ________.

Accepted Answer

A) -44.2 
B) -3.88 × 103 
C) -7.28 × 103  
D) -708.4 
E) -649.5 
A) -44.2 
B) -3.88 × 103 
C) -7.28 × 103  
D) -708.4 
E) -649.5

Question 14

Define allotrope.

Accepted Answer

An allotrope is an e

Question 15

What is "free" energy? Give a fictitious example.

Accepted Answer

Consider a reaction that is exothermic (

Question 16

Calculate the ΔG°rxn using the following information.
2 HNO3(aq)+ NO(g)→ 3 NO2(g)+ H2O(l)ΔG°rxn = ?
ΔH°f (kJ/mol)-207.0 91.3 33.2 -285.8
S°(J/mol∙K)46.0 210.8 240.1 70.0

Accepted Answer

A) -151 kJ 
B) -85.5 kJ 
C) +50.8 kJ 
D) +222 kJ 
E) -186 kJ 
A) -151 kJ 
B) -85.5 kJ 
C) +50.8 kJ 
D) +222 kJ 
E) -186 kJ

Question 17

Use Hess's law to calculate ΔG°rxn using the following information.
NO(g)+ O(g)→ NO2(g)ΔG°rxn = ?
2 O3(g)→ 3 O2(g)ΔG°rxn = +489.6 kJ
O2(g)→ 2 O(g)ΔG°rxn = +463.4 kJ
NO(g)+ O3(g)→ NO2(g)+ O2(g)ΔG°rxn = -199.5 kJ

Accepted Answer

A) +753.5 kJ 
B) +277.0 kJ 
C) -676.0 kJ 
D) -1152.5 kJ 
E) -225.7 kJ 
A) +753.5 kJ 
B) +277.0 kJ 
C) -676.0 kJ 
D) -1152.5 kJ 
E) -225.7 kJ

Question 18

Which of the following relationships is correct at constant T and P?

Accepted Answer

A) ΔG is proportional to -ΔSuniv. B) ΔG > 0 represents a spontaneous process. C) ΔG > 0 represents an increase in kinetic energy. D) ΔG < 0 represents a nonspontaneous process. E) All of the above are correct. A) ΔG is proportional to -ΔSuniv. B) ΔG > 0 represents a spontaneous process. C) ΔG > 0 represents an increase in kinetic energy. D) ΔG < 0 represents a nonspontaneous process. E) All of the above are correct.

Question 19

Determine ΔG°rxn using the following information.
CaCO3(s)→ CaO(s)+ CO2(g)ΔH° = +179.2 kJ;ΔS° = +160.2 J/K

Accepted Answer

A) -607.0 kJ 
B) +112 .0 kJ 
C) -89.3 kJ 
D) +131.4 kJ 
E) +228.1 kJ 
A) -607.0 kJ 
B) +112 .0 kJ 
C) -89.3 kJ 
D) +131.4 kJ 
E) +228.1 kJ

Question 20

Why can't we say that a spontaneous reaction is a fast reaction?

Accepted Answer

Spontaneity is a thermodynamic

Match the following. -Q = K

Which of the following statements is true?

Calculate ΔS°_rxn for the following reaction.The S° for each species is shown below the reaction. P₄(g)+ 10 Cl₂(g)→ 4 PCl₅(g) S°(J/mol^∙K)280.0 223.1 364.6

Determine the equilibrium constant for the following reaction at 655 K. HCN(g)+ 2 H₂(g)→ CH₃NH₂(g)ΔH° = -158 kJ;ΔS°= -219.9 J/K

Determine the equilibrium constant for the following reaction at 549 K. CH₂O(g)+ 2 H₂(g)→ CH₄(g)+ H₂O(g) ΔH° = -94.9 kJ;ΔS° = -224.2 J/K

Which of the following processes has a ΔS < 0?

Identify the compound that is not an allotrope of carbon.

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

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

The value of ΔG° at 100.0 °C for the formation of calcium chloride from its constituent elements: Ca(s)+ Cl₂(g)→ CaCl₂(s) Is ________ kJ/mol.At 25.0°C for this reaction,ΔH° is -795.8 kJ/mol,ΔG° is -748.1 kJ/mol,and ΔS° is -159.8 J/K.

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

Estimate ΔG°_rxn for the following reaction at 775 K. 2 Hg(g)+ O₂(g)→ 2 HgO(s)ΔH° = -304.2 kJ;ΔS° = -414.2 J/K

Phosphorous and chlorine gases combine to produce phosphorous trichloride: P₂(g)+ 3Cl₂(g)→ 2PCl₃(g) ΔG° at 298 K for this reaction is -642.9 kJ/mol.The value of ΔG at 298 K for a reaction mixture that consists of 1.5 atm P₂,1.6 atm Cl₂,and 0.65 atm PCl₃ is ________.

Define allotrope.

What is "free" energy? Give a fictitious example.

Calculate the ΔG°_rxn using the following information. 2 HNO₃(aq)+ NO(g)→ 3 NO₂(g)+ H₂O(l)ΔG°_rxn= ? ΔH°_f (kJ/mol)-207.0 91.3 33.2 -285.8 S°(J/mol^∙K)46.0 210.8 240.1 70.0

Use Hess's law to calculate ΔG°_rxn using the following information. NO(g)+ O(g)→ NO₂(g)ΔG°_rxn= ? 2 O₃(g)→ 3 O₂(g)ΔG°_rxn= +489.6 kJ O₂(g)→ 2 O(g)ΔG°_rxn= +463.4 kJ NO(g)+ O₃(g)→ NO₂(g)+ O₂(g)ΔG°_rxn= -199.5 kJ

Which of the following relationships is correct at constant T and P?

Determine ΔG°_rxn using the following information. CaCO₃(s)→ CaO(s)+ CO₂(g)ΔH° = +179.2 kJ;ΔS° = +160.2 J/K

Why can't we say that a spontaneous reaction is a fast reaction?

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Exam 17: Free Energy and Thermodynamics

Match the following. -Q = K

Which of the following statements is true?

Calculate ΔS°rxn for the following reaction.The S° for each species is shown below the reaction. P4(g)+ 10 Cl2(g)→ 4 PCl5(g) S°(J/mol∙K)280.0 223.1 364.6

Determine the equilibrium constant for the following reaction at 655 K. HCN(g)+ 2 H2(g)→ CH3NH2(g)ΔH° = -158 kJ;ΔS°= -219.9 J/K

Determine the equilibrium constant for the following reaction at 549 K. CH2O(g)+ 2 H2(g)→ CH4(g)+ H2O(g) ΔH° = -94.9 kJ;ΔS° = -224.2 J/K

Which of the following processes has a ΔS < 0?

Identify the compound that is not an allotrope of carbon.

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

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

The value of ΔG° at 100.0 °C for the formation of calcium chloride from its constituent elements: Ca(s)+ Cl2(g)→ CaCl2(s) Is ________ kJ/mol.At 25.0°C for this reaction,ΔH° is -795.8 kJ/mol,ΔG° is -748.1 kJ/mol,and ΔS° is -159.8 J/K.

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

Estimate ΔG°rxn for the following reaction at 775 K. 2 Hg(g)+ O2(g)→ 2 HgO(s)ΔH° = -304.2 kJ;ΔS° = -414.2 J/K

Phosphorous and chlorine gases combine to produce phosphorous trichloride: P2(g)+ 3Cl2(g)→ 2PCl3(g) ΔG° at 298 K for this reaction is -642.9 kJ/mol.The value of ΔG at 298 K for a reaction mixture that consists of 1.5 atm P2,1.6 atm Cl2,and 0.65 atm PCl3 is ________.

Define allotrope.

What is "free" energy? Give a fictitious example.

Calculate the ΔG°rxn using the following information. 2 HNO3(aq)+ NO(g)→ 3 NO2(g)+ H2O(l)ΔG°rxn = ? ΔH°f (kJ/mol)-207.0 91.3 33.2 -285.8 S°(J/mol∙K)46.0 210.8 240.1 70.0

Use Hess's law to calculate ΔG°rxn using the following information. NO(g)+ O(g)→ NO2(g)ΔG°rxn = ? 2 O3(g)→ 3 O2(g)ΔG°rxn = +489.6 kJ O2(g)→ 2 O(g)ΔG°rxn = +463.4 kJ NO(g)+ O3(g)→ NO2(g)+ O2(g)ΔG°rxn = -199.5 kJ

Which of the following relationships is correct at constant T and P?

Determine ΔG°rxn using the following information. CaCO3(s)→ CaO(s)+ CO2(g)ΔH° = +179.2 kJ;ΔS° = +160.2 J/K

Why can't we say that a spontaneous reaction is a fast reaction?

Matter, Measurement, and Problem Solving

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Gases

Thermochemistry

The Quantum-Mechanical Model of the Atom

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Chemical Bonding I: Lewis Theory

Chemical Bonding II: Molecular Shapes, Valence Bond Theory, and

Liquids, Solids, and Intermolecular Forces

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Calculate ΔS°_rxn for the following reaction.The S° for each species is shown below the reaction. P₄(g)+ 10 Cl₂(g)→ 4 PCl₅(g) S°(J/mol^∙K)280.0 223.1 364.6

Determine the equilibrium constant for the following reaction at 655 K. HCN(g)+ 2 H₂(g)→ CH₃NH₂(g)ΔH° = -158 kJ;ΔS°= -219.9 J/K

Determine the equilibrium constant for the following reaction at 549 K. CH₂O(g)+ 2 H₂(g)→ CH₄(g)+ H₂O(g) ΔH° = -94.9 kJ;ΔS° = -224.2 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

The value of ΔG° at 100.0 °C for the formation of calcium chloride from its constituent elements: Ca(s)+ Cl₂(g)→ CaCl₂(s) Is ________ kJ/mol.At 25.0°C for this reaction,ΔH° is -795.8 kJ/mol,ΔG° is -748.1 kJ/mol,and ΔS° is -159.8 J/K.

Estimate ΔG°_rxn for the following reaction at 775 K. 2 Hg(g)+ O₂(g)→ 2 HgO(s)ΔH° = -304.2 kJ;ΔS° = -414.2 J/K

Phosphorous and chlorine gases combine to produce phosphorous trichloride: P₂(g)+ 3Cl₂(g)→ 2PCl₃(g) ΔG° at 298 K for this reaction is -642.9 kJ/mol.The value of ΔG at 298 K for a reaction mixture that consists of 1.5 atm P₂,1.6 atm Cl₂,and 0.65 atm PCl₃ is ________.

Calculate the ΔG°_rxn using the following information. 2 HNO₃(aq)+ NO(g)→ 3 NO₂(g)+ H₂O(l)ΔG°_rxn= ? ΔH°_f (kJ/mol)-207.0 91.3 33.2 -285.8 S°(J/mol^∙K)46.0 210.8 240.1 70.0

Use Hess's law to calculate ΔG°_rxn using the following information. NO(g)+ O(g)→ NO₂(g)ΔG°_rxn= ? 2 O₃(g)→ 3 O₂(g)ΔG°_rxn= +489.6 kJ O₂(g)→ 2 O(g)ΔG°_rxn= +463.4 kJ NO(g)+ O₃(g)→ NO₂(g)+ O₂(g)ΔG°_rxn= -199.5 kJ

Determine ΔG°_rxn using the following information. CaCO₃(s)→ CaO(s)+ CO₂(g)ΔH° = +179.2 kJ;ΔS° = +160.2 J/K