Question 1

Is the following process spontaneous?

Accepted Answer

A) Yes, because ΔH > 0. B) No, because ΔH 0. D) No, because ΔS < 0. E) It's impossible to tell without knowing the temperature of the system. A) Yes, because ΔH > 0. B) No, because ΔH 0. D) No, because ΔS < 0. E) It's impossible to tell without knowing the temperature of the system. E

Question 2

The temperature at which the following process reaches equilibrium at 1.0 atm is the normal melting point for phosphoric acid. H3PO4(s)   H3PO4(l)
Use the following thermodynamic data at 298 K to estimate this temperature.

Accepted Answer

A)  286 K 
B)  305 K 
C)  315 K 
D)  347 K 
E)  3170 K 
A)  286 K 
B)  305 K 
C)  315 K 
D)  347 K 
E)  3170 K C

Question 3

What is defined as a process that may occur under a specific set of conditions?

Accepted Answer

A)  Conditional process 
B)  Nonspontaneous process 
C)  Specified process 
D)  Spontaneous process 
E)  Conditionality law 
A)  Conditional process 
B)  Nonspontaneous process 
C)  Specified process 
D)  Spontaneous process 
E)  Conditionality law D

Question 4

How does the entropy change when a solid is melted?

Accepted Answer

The answer of How does the entropy change when a...

Question 5

What is ΔS° for the reaction SO2(s) + NO2(g) → SO3(g) + NO(g)?

Accepted Answer

A)  53.6 J/K • mol 
B)  -53.6 J/K • mol 
C)  -22.2 J/K • mol 
D)  474.8 J/K • mol 
E)  -474.8 J/K • mol 
A)  53.6 J/K • mol 
B)  -53.6 J/K • mol 
C)  -22.2 J/K • mol 
D)  474.8 J/K • mol 
E)  -474.8 J/K • mol

Question 6

Elemental boron can be formed by the reaction of boron trichloride with hydrogen. 2BCl3(g) + 3H2(g) → 2B(s) + 6HCl(g)

Accepted Answer

A)  -18.2 J/K • mol 
B)  18.2 J/K • mol 
C)  289.5 J/K • mol 
D)  370.4 J/K • mol 
E)  579.0 J/K • mol 
A)  -18.2 J/K • mol 
B)  18.2 J/K • mol 
C)  289.5 J/K • mol 
D)  370.4 J/K • mol 
E)  579.0 J/K • mol

Question 7

Elemental boron can be formed by the reaction of boron trichloride with hydrogen. 2BCl3(g) + 3H2(g) → 2B(s) + 6HCl(g)
What is ΔG°rxn for this reaction?

Accepted Answer

A)  -293.4 kJ/mol 
B)  293.4 kJ/mol 
C)  -205.6 kJ/mol 
D)  205.6 kJ/mol 
E)  -2141.6 kJ/mol 
A)  -293.4 kJ/mol 
B)  293.4 kJ/mol 
C)  -205.6 kJ/mol 
D)  205.6 kJ/mol 
E)  -2141.6 kJ/mol

Question 8

What is ΔG°rxn for the following reaction? SiCl4(g) + 2Mg(s) → 2MgCl2(s) + Si(s)

Accepted Answer

A)  566.60 kJ/mol 
B)  50.38 kJ/mol 
C)  25.19 kJ/mol 
D)  -25.19 kJ/mol 
E)  -566.60 kJ/mol 
A)  566.60 kJ/mol 
B)  50.38 kJ/mol 
C)  25.19 kJ/mol 
D)  -25.19 kJ/mol 
E)  -566.60 kJ/mol

Question 9

What is ΔS° for the reaction SO3(g) + H2O(l) → H2SO4(aq)?

Accepted Answer

A)  169.2 J/K • mol 
B)  343.2 J/K • mol 
C)  -169.2 J/K • mol 
D)  -29.4 J/K • mol 
E)  29.4 J/K • mol 
A)  169.2 J/K • mol 
B)  343.2 J/K • mol 
C)  -169.2 J/K • mol 
D)  -29.4 J/K • mol 
E)  29.4 J/K • mol

Question 10

Which statement is correct?

Accepted Answer

A)  Reaction of ADP and alanine results in ATP in the body. 
B)  A positive ΔG° value means that the reaction is not product favored. 
C)  CO2 is released when ADP reacts with an amino acid. 
D)  Phosphoric acid is one of the products of the reaction of ADP with alanine. 
E)  Hydrolysis of ATP requires NaOH. 
A)  Reaction of ADP and alanine results in ATP in the body. 
B)  A positive ΔG° value means that the reaction is not product favored. 
C)  CO2 is released when ADP reacts with an amino acid. 
D)  Phosphoric acid is one of the products of the reaction of ADP with alanine. 
E)  Hydrolysis of ATP requires NaOH.

Question 11

The ________ law of thermodynamics states that the entropy of the universe in a spontaneous process increases and is constant in equilibrium processes.

Accepted Answer

The answer of The ________ law of thermodynamics states that...

Question 12

In a spontaneous process, the entropy of the system always increases.

Accepted Answer

A) True 
 B)False

Question 13

The entropy of vaporization of a compound is always positive.

Accepted Answer

A) True 
 B)False

Question 14

How many types of vibrations does a diatomic molecule exhibit?

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  3 
E)  4 
A)  0 
B)  1 
C)  2 
D)  3 
E)  4

Question 15

The reaction of methane with water to form carbon dioxide and hydrogen is nonspontaneous at 98 K. At what temperature will this system make the transition from nonspontaneous to spontaneous? The following data are valid at 298 K: CH4(g) + 2H2O(g)   CO2(g) + 4H2(g)

Accepted Answer

A)  658 K 
B)  683 K 
C)  955 K 
D)  1047 K 
E)  1229 K 
A)  658 K 
B)  683 K 
C)  955 K 
D)  1047 K 
E)  1229 K

Question 16

Which thermodynamic property is a measure of the disorder in the system?

Accepted Answer

The answer of Which thermodynamic property is a measure of...

Question 17

What is ΔS° at 25°C for the reduction of lead(II) oxide by charcoal? 2PbO(s) + C(s) → 2Pb(s) + CO2(g)

Accepted Answer

A)  +198.7 J/K • mol 
B)  +488.0 J/K • mol 
C)  +353.7J/K • mol 
D)  -203.3 J/K • mol 
E)  +203.3 J/K • mol 
A)  +198.7 J/K • mol 
B)  +488.0 J/K • mol 
C)  +353.7J/K • mol 
D)  -203.3 J/K • mol 
E)  +203.3 J/K • mol

Question 18

If an endothermic process is spontaneous when |TΔS| >|ΔH|, then is ΔS is positive, negative, or equal to zero?

Accepted Answer

The answer of If an endothermic process is spontaneous when...

Question 19

Consider the figure below which shows ΔG° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that:

Accepted Answer

A) ΔH° > 0, ΔS° > 0 B) ΔH° > 0, ΔS° 0 D) ΔH° < 0, ΔS° < 0 E) None of these choices is correct. A) ΔH° > 0, ΔS° > 0 B) ΔH° > 0, ΔS° 0 D) ΔH° < 0, ΔS° < 0 E) None of these choices is correct.

Question 20

Consider the figure below which shows ΔG° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that:

Accepted Answer

A) ΔH° > 0, ΔS° > 0 B) ΔH° > 0, ΔS° 0 D) ΔH° < 0, ΔS° < 0 E) None of these choices is correct. A) ΔH° > 0, ΔS° > 0 B) ΔH° > 0, ΔS° 0 D) ΔH° < 0, ΔS° < 0 E) None of these choices is correct.

Exam 18: Entropy, Free Energy, and Equilibrium

Is the following process spontaneous?

The temperature at which the following process reaches equilibrium at 1.0 atm is the normal melting point for phosphoric acid. H3PO4(s) H3PO4(l) Use the following thermodynamic data at 298 K to estimate this temperature.

What is defined as a process that may occur under a specific set of conditions?

How does the entropy change when a solid is melted?

What is ΔS° for the reaction SO2(s) + NO2(g) → SO3(g) + NO(g)?

Elemental boron can be formed by the reaction of boron trichloride with hydrogen. 2BCl3(g) + 3H2(g) → 2B(s) + 6HCl(g)

Elemental boron can be formed by the reaction of boron trichloride with hydrogen. 2BCl3(g) + 3H2(g) → 2B(s) + 6HCl(g) What is ΔG°rxn for this reaction?

What is ΔG°rxn for the following reaction? SiCl4(g) + 2Mg(s) → 2MgCl2(s) + Si(s)

What is ΔS° for the reaction SO3(g) + H2O(l) → H2SO4(aq)?

Which statement is correct?

The ________ law of thermodynamics states that the entropy of the universe in a spontaneous process increases and is constant in equilibrium processes.

In a spontaneous process, the entropy of the system always increases.

The entropy of vaporization of a compound is always positive.

How many types of vibrations does a diatomic molecule exhibit?

The reaction of methane with water to form carbon dioxide and hydrogen is nonspontaneous at 98 K. At what temperature will this system make the transition from nonspontaneous to spontaneous? The following data are valid at 298 K: CH4(g) + 2H2O(g) CO2(g) + 4H2(g)

Which thermodynamic property is a measure of the disorder in the system?

What is ΔS° at 25°C for the reduction of lead(II) oxide by charcoal? 2PbO(s) + C(s) → 2Pb(s) + CO2(g)

If an endothermic process is spontaneous when |TΔS| >|ΔH|, then is ΔS is positive, negative, or equal to zero?

Consider the figure below which shows ΔG° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that:

Consider the figure below which shows ΔG° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that:

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The temperature at which the following process reaches equilibrium at 1.0 atm is the normal melting point for phosphoric acid. H₃PO₄(s) H₃PO₄(l) Use the following thermodynamic data at 298 K to estimate this temperature.

What is ΔS° for the reaction SO₂(s) + NO₂(g) → SO₃(g) + NO(g)?

Elemental boron can be formed by the reaction of boron trichloride with hydrogen. 2BCl₃(g) + 3H₂(g) → 2B(s) + 6HCl(g)

Elemental boron can be formed by the reaction of boron trichloride with hydrogen. 2BCl₃(g) + 3H₂(g) → 2B(s) + 6HCl(g) What is ΔG°_rxn for this reaction?

What is ΔG°_rxn for the following reaction? SiCl₄(g) + 2Mg(s) → 2MgCl₂(s) + Si(s)

What is ΔS° for the reaction SO₃(g) + H₂O(l) → H₂SO₄(aq)?

The reaction of methane with water to form carbon dioxide and hydrogen is nonspontaneous at 98 K. At what temperature will this system make the transition from nonspontaneous to spontaneous? The following data are valid at 298 K: CH₄(g) + 2H₂O(g) CO₂(g) + 4H₂(g)

What is ΔS° at 25°C for the reduction of lead(II) oxide by charcoal? 2PbO(s) + C(s) → 2Pb(s) + CO₂(g)