Question 1

Some pure metals can be obtained from their ores simply by heating to a high temperature to drive off the oxygen, but iron ore usually is refined by reacting it with carbon monoxide. Use the information in the following table to determine whether or not iron ore could be refined by heating to a high temperature and, if so, how high the temperature must be. The oxidation reaction producing iron ore is given below.  Thermodynamic Properties

Accepted Answer

A)  Iron ore cannot be refined by heating because the oxidation reaction is spontaneous in the forward direction at all temperatures.
B)  Iron ore could be refined by heating, but temperatures in the range 500-1,000 K are needed.
C)  Iron ore could be refined by heating, but temperatures in the range 2,000-3,000 K are needed.
D)  Iron ore could be refined by heating, but temperatures in the range 1,000-2,000 K are needed.
E)  Iron ore could be refined by heating, but the temperature must be greater than 3,000 K.F) All of the above
G) C) and D)

Question 2

An ice cube at 0C melts in a swimming pool at 25C. What is the change in the entropy of the universe as a result? The ice cube was 2.00 inches on a side. Assume ice has a density of 0.917 g/cm3 and that the enthalpy of fusion of water is 6.01 kJ/mol.

Accepted Answer

A)  (3.1 J/K) 
B)  (3.1 J/K) 
C)  0.0 J/K
D)  (12.3 J/K) 
E)  (12.3 J/K) F) All of the above
G) A) and E)

Question 3

Given the following data relevant to the combustion of ethanol, determine the free energy of formation for liquid ethanol, C2H5OH. 2H5OH.   (C2H5OH, l) 930.7 kJ/mol   (CO2, g) 394.4 kJ/mol   (H2O, g) 105.6 kJ/mol A) (1,640.3 kJ/mol)  B) (244.2 kJ/mol)  C) (174.9 kJ/mol)  D) (174.9 kJ/mol)  E) (244.2 kJ/mol) " class="answers-bank-image d-inline" rel="preload" > (C2H5OH, l) 930.7 kJ/mol 2H5OH.   (C2H5OH, l) 930.7 kJ/mol   (CO2, g) 394.4 kJ/mol   (H2O, g) 105.6 kJ/mol A) (1,640.3 kJ/mol)  B) (244.2 kJ/mol)  C) (174.9 kJ/mol)  D) (174.9 kJ/mol)  E) (244.2 kJ/mol) " class="answers-bank-image d-inline" rel="preload" > (CO2, g) 394.4 kJ/mol 2H5OH.   (C2H5OH, l) 930.7 kJ/mol   (CO2, g) 394.4 kJ/mol   (H2O, g) 105.6 kJ/mol A) (1,640.3 kJ/mol)  B) (244.2 kJ/mol)  C) (174.9 kJ/mol)  D) (174.9 kJ/mol)  E) (244.2 kJ/mol) " class="answers-bank-image d-inline" rel="preload" > (H2O, g) 105.6 kJ/mol

Accepted Answer

A)  (1,640.3 kJ/mol) 
B)  (244.2 kJ/mol) 
C)  (174.9 kJ/mol) 
D)  (174.9 kJ/mol) 
E)  (244.2 kJ/mol) F) C) and E)
G) B) and C)

Question 4

Nitrogen monoxide molecules can react to form dinitrogen oxide and nitrogen dioxide. Determine the equilibrium constant for this reaction under standard conditions from the following data and note whether the reaction is product-favored or reactant-favored.F1F1F1S1F1F1F10GF1F1F1S1F1F1F10(NO, g) F1F1F1S1F1F1F10 86.6 kJ/molF1F1F1S1F1F1F10GF1F1F1S1F1F1F10(N2O, g) F1F1F1S1F1F1F10 104.2 kJ/molF1F1F1S1F1F1F10GF1F1F1S1F1F1F10(NO2, g) F1F1F1S1F1F1F10 51.3 kJ/mol

Accepted Answer

K <font face="symbol"></font> 1...

Question 5

Which of the processes A-D will lead to a positive change in the entropy of the system?

Accepted Answer

A)  Sodium chloride crystals form as salt water evaporates.
B)  Helium gas escapes from the hole in a balloon.
C)  Stalactites form in a cave.
D)  Water freezes in a freezer.
E)  All of these lead to a positive change in entropy of the system, because they are all spontaneous.F) B) and E)
G) A) and E)

Question 6

In a biochemical reaction, A  B  C with  B  C with    30 kJ/mol. Which of the following reactions might be effectively coupled to this reaction so that it becomes more spontaneous? I.C  D  B  E    40 kJ/mol II.C  D  B  E    40 kJ/mol A) I only B) II only C) I or II D) Neither I nor II can increase spontaneity. E) No coupling is required, because the reaction is already spontaneous." class="answers-bank-image d-inline" rel="preload" >  30 kJ/mol. Which of the following reactions might be effectively coupled to this reaction so that it becomes more spontaneous?
I.C  D  B  E  B  C with    30 kJ/mol. Which of the following reactions might be effectively coupled to this reaction so that it becomes more spontaneous? I.C  D  B  E    40 kJ/mol II.C  D  B  E    40 kJ/mol A) I only B) II only C) I or II D) Neither I nor II can increase spontaneity. E) No coupling is required, because the reaction is already spontaneous." class="answers-bank-image d-inline" rel="preload" >  40 kJ/mol
II.C  D  B  E  B  C with    30 kJ/mol. Which of the following reactions might be effectively coupled to this reaction so that it becomes more spontaneous? I.C  D  B  E    40 kJ/mol II.C  D  B  E    40 kJ/mol A) I only B) II only C) I or II D) Neither I nor II can increase spontaneity. E) No coupling is required, because the reaction is already spontaneous." class="answers-bank-image d-inline" rel="preload" >  40 kJ/mol

Accepted Answer

A)  I only
B)  II only
C)  I or II
D)  Neither I nor II can increase spontaneity.
E)  No coupling is required, because the reaction is already spontaneous.F) B) and E)
G) C) and D)

Question 7

At what temperature does the Fe(s)  H  415.5 kJ/mol; S  153.4 J/mol · K. A) 2,162F B) 2,435F C) 4,352F D) 4,416F E) 2,709F" class="answers-bank-image d-inline" rel="preload" > Fe(g)  phase transition occur?H  415.5 kJ/mol; S  153.4 J/mol · K.

Accepted Answer

A)  2,162F
B)  2,435F
C)  4,352F
D)  4,416F
E)  2,709FF) B) and D)
G) C) and D)

Question 8

What is a microstate and how are microstates quantitatively related to entropy?

Accepted Answer

A microstate is a unique distr...

Question 9

The dissolution of ammonium nitrate in water is a spontaneous endothermic process. It is spontaneous because the system undergoes ________

Accepted Answer

A)  a decrease in enthalpy.
B)  an increase in entropy.
C)  an increase in enthalpy.
D)  a decrease in entropy.
E)  an increase in free energy.F) None of the above
G) A) and B)

Question 10

One of the following statements A-D may be incorrect. If so, identify it.

Accepted Answer

A)  If both H and S are positive, then a reaction will be spontaneous and produce products only at a sufficiently high temperature.
B)  If both H and S are negative, then a reaction will be spontaneous and produce products only at a sufficiently low temperature.
C)  If H  0 and S  0, then a reaction is not spontaneous and will not produce products at any temperature.
D)  If H  0 and S  0, then a reaction is spontaneous and will produce products at any temperature.
E)  All of the statements A-D are correct.F) D) and E)
G) C) and D)

Question 11

Which of the listed perturbations would change the value of the equilibrium constant for the following reaction? List those that do as a sequence of letters, for example, ACE.
NH4CO2NH2(s)  4CO2NH2(s)    2NH3(g)   CO2(g)  A)  Increasing the quantity of NH4CO2NH2(s)  B)  Removing CO2(g)  C)  Increasing the total pressure by adding argon gas D)  Increasing the volume of the container E)  Increasing the temperature " class="answers-bank-image d-inline" rel="preload" > 2NH3(g)   CO2(g)

Accepted Answer

A)   Increasing the quantity of NH4CO2NH2(s) 
B)   Removing CO2(g) 
C)   Increasing the total pressure by adding argon gas
D)   Increasing the volume of the container
E)   Increasing the temperatureF) A) and B)
G) A) and E)

Question 12

Which of the following processes is/are reversible in the thermodynamic sense?
I. Iron in the open air rusts.
II. NaCl is dissolved in water and then recovered by the evaporation of the water.
III. The ice in a mixture of ice and water at 0C and 1 atm melts.

Accepted Answer

A)  I only
B)  II only
C)  III only
D)  II and III only
E)  I, II, and III are all reversible.F) B) and D)
G) B) and C)

Question 13

Give an example of a spontaneous and a nonspontaneous chemical process and the sign of the entropy change for the universe for each.

Accepted Answer

The burning of alkane gases and the free...

Question 14

Draw a graph of entropy versus temperature for a typical substance. Be sure to clearly label phases and phase transitions on the graph.

Accepted Answer

Example from the text:
Graph ...

Question 15

Which of the relationships between the free-energy change of a system and associated entropy changes is true?

Accepted Answer

A)  (Gsys  T Ssystem) 
B)  (Gsys  T Ssystem) 
C)  (Gsys  T Suniverse) 
D)  (Gsys  T Ssurroundings) 
E)  (Gsys  T Suniverse) F) C) and D)
G) None of the above

Question 16

Which of the following statements is/are correct? A large negative free-energy change for a reaction means that ________
I. the equilibrium constant for the reaction is large.
II. the equilibrium constant for the reaction is small.
III. the reaction greatly favors formation of the products.
IV. only a small amount of product is produced at equilibrium.

Accepted Answer

A)  I only
B)  II only
C)  both I and III
D)  both I and IV
E)  both II and IVF) A) and C)
G) D) and E)

Question 17

Which of the following figures illustrates best the sequence of the free-energy values (shown with the star)  for a chemical reaction at equilibrium to the removal of products, followed by the response of the equilibrium to this stress?

Accepted Answer

A)   
B)   
C)   
D)   E) B) and D)
F) A) and B)

Question 18

Determine the value of G for the reaction at 298 K. G for the reaction at 298 K.   Given   A) (962 kJ)  B) (573 kJ)  C) (573 kJ)  D) (817 kJ)  E) (817 kJ) " class="answers-bank-image d-inline" rel="preload" > Given G for the reaction at 298 K.   Given   A) (962 kJ)  B) (573 kJ)  C) (573 kJ)  D) (817 kJ)  E) (817 kJ) " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  (962 kJ) 
B)  (573 kJ) 
C)  (573 kJ) 
D)  (817 kJ) 
E)  (817 kJ) F) A) and E)
G) C) and D)

Question 19

If for a given chemical reaction at 298 K, both the change in free energy, G, and the change in the standard free energy, G , are positive with G G , then ________

Accepted Answer

A)  Q  K and product is turning back into reactant.
B)  Q  K and more product is being produced.
C)  Q  K and product is turning back into reactant.
D)  Q  K and more product is being produced.
E)  Q  K and the reaction has stopped.F) C) and D)
G) A) and C)

Question 20

Indicate which of the following has the smallest standard molar entropy (S) .

Accepted Answer

A)  NH3(g) 
B)  H2O(l) 
C)  Mg(s) 
D)  Hg(l ) 
E)  Ar(g) F) A) and B)
G) B) and D)

Exam 17: Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

At what temperature does the Fe(s) Fe(g) phase transition occur?H 415.5 kJ/mol; S  153.4 J/mol · K.

Correct Answer
verified

Determine the value of G for the reaction at 298 K. Given

Correct Answer
verified

Correct Answer
verified

Which of the following figures illustrates best the sequence of the free-energy values (shown with the star) for a chemical reaction at equilibrium to the removal of products, followed by the response of the equilibrium to this stress?

Correct Answer
verified

Indicate which of the following has the smallest standard molar entropy (S) .

Correct Answer
verified

Which of the processes A-D will lead to a positive change in the entropy of the system?

Correct Answer
verified

In a biochemical reaction, A  B  C with  30 kJ/mol. Which of the following reactions might be effectively coupled to this reaction so that it becomes more spontaneous? I.C  D  B  E  40 kJ/mol II.C  D  B  E  40 kJ/mol

Correct Answer
verified

Correct Answer
verified
K  1...
View Answer

One of the following statements A-D may be incorrect. If so, identify it.

Correct Answer
verified

Given the following data relevant to the combustion of ethanol, determine the free energy of formation for liquid ethanol, C₂H₅OH. (C₂H₅OH, l) 930.7 kJ/mol (CO₂, g) 394.4 kJ/mol (H₂O, g) 105.6 kJ/mol

Correct Answer
verified

Which of the following processes is/are reversible in the thermodynamic sense? I. Iron in the open air rusts. II. NaCl is dissolved in water and then recovered by the evaporation of the water. III. The ice in a mixture of ice and water at 0C and 1 atm melts.

Correct Answer
verified

If for a given chemical reaction at 298 K, both the change in free energy, G, and the change in the standard free energy, G , are positive with G G , then ________

Correct Answer
verified

Which of the listed perturbations would change the value of the equilibrium constant for the following reaction? List those that do as a sequence of letters, for example, ACE. NH₄CO₂NH₂(s) 2NH₃(g)  CO₂(g)

Correct Answer
verified

Give an example of a spontaneous and a nonspontaneous chemical process and the sign of the entropy change for the universe for each.

Correct Answer
verified
The burning of alkane gases and the free...
View Answer

Draw a graph of entropy versus temperature for a typical substance. Be sure to clearly label phases and phase transitions on the graph.

Correct Answer
verified
Example from the text:
Graph ...
View Answer

What is a microstate and how are microstates quantitatively related to entropy?

Correct Answer
verified
A microstate is a unique distr...
View Answer

Which of the relationships between the free-energy change of a system and associated entropy changes is true?

Correct Answer
verified

Correct Answer
verified

The dissolution of ammonium nitrate in water is a spontaneous endothermic process. It is spontaneous because the system undergoes ________

Correct Answer
verified

An ice cube at 0C melts in a swimming pool at 25C. What is the change in the entropy of the universe as a result? The ice cube was 2.00 inches on a side. Assume ice has a density of 0.917 g/cm³ and that the enthalpy of fusion of water is 6.01 kJ/mol.

Correct Answer
verified

Exam 17: Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

At what temperature does the Fe(s) Fe(g) phase transition occur?H  415.5 kJ/mol; S  153.4 J/mol · K.

Correct AnswerverifiedShow Answer

Determine the value of G for the reaction at 298 K. Given

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following figures illustrates best the sequence of the free-energy values (shown with the star) for a chemical reaction at equilibrium to the removal of products, followed by the response of the equilibrium to this stress?

Correct AnswerverifiedShow Answer

Indicate which of the following has the smallest standard molar entropy (S) .

Correct AnswerverifiedShow Answer

Which of the processes A-D will lead to a positive change in the entropy of the system?

Correct AnswerverifiedShow Answer

In a biochemical reaction, A  B  C with  30 kJ/mol. Which of the following reactions might be effectively coupled to this reaction so that it becomes more spontaneous? I.C  D  B  E  40 kJ/mol II.C  D  B  E  40 kJ/mol

Correct AnswerverifiedShow Answer

Correct AnswerverifiedK  1...View AnswerShow Answer

One of the following statements A-D may be incorrect. If so, identify it.

Correct AnswerverifiedShow Answer

Given the following data relevant to the combustion of ethanol, determine the free energy of formation for liquid ethanol, C2H5OH. (C2H5OH, l) 930.7 kJ/mol (CO2, g) 394.4 kJ/mol (H2O, g) 105.6 kJ/mol

Correct AnswerverifiedShow Answer

Which of the following processes is/are reversible in the thermodynamic sense? I. Iron in the open air rusts. II. NaCl is dissolved in water and then recovered by the evaporation of the water. III. The ice in a mixture of ice and water at 0C and 1 atm melts.

Correct AnswerverifiedShow Answer

If for a given chemical reaction at 298 K, both the change in free energy, G, and the change in the standard free energy, G , are positive with G G , then ________

Correct AnswerverifiedShow Answer

Which of the listed perturbations would change the value of the equilibrium constant for the following reaction? List those that do as a sequence of letters, for example, ACE. NH4CO2NH2(s) 2NH3(g)  CO2(g)

Correct AnswerverifiedShow Answer

Give an example of a spontaneous and a nonspontaneous chemical process and the sign of the entropy change for the universe for each.

Correct AnswerverifiedThe burning of alkane gases and the free...View AnswerShow Answer

Draw a graph of entropy versus temperature for a typical substance. Be sure to clearly label phases and phase transitions on the graph.

Correct Answerverified Example from the text:Graph ...View AnswerShow Answer

What is a microstate and how are microstates quantitatively related to entropy?

Correct AnswerverifiedA microstate is a unique distr...View AnswerShow Answer

Which of the relationships between the free-energy change of a system and associated entropy changes is true?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The dissolution of ammonium nitrate in water is a spontaneous endothermic process. It is spontaneous because the system undergoes ________

Correct AnswerverifiedShow Answer

An ice cube at 0C melts in a swimming pool at 25C. What is the change in the entropy of the universe as a result? The ice cube was 2.00 inches on a side. Assume ice has a density of 0.917 g/cm3 and that the enthalpy of fusion of water is 6.01 kJ/mol.

Correct AnswerverifiedShow Answer

At what temperature does the Fe(s) Fe(g) phase transition occur?H 415.5 kJ/mol; S  153.4 J/mol · K.

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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K  1...
View Answer

Correct Answer
verified

Given the following data relevant to the combustion of ethanol, determine the free energy of formation for liquid ethanol, C₂H₅OH. (C₂H₅OH, l) 930.7 kJ/mol (CO₂, g) 394.4 kJ/mol (H₂O, g) 105.6 kJ/mol

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Which of the listed perturbations would change the value of the equilibrium constant for the following reaction? List those that do as a sequence of letters, for example, ACE. NH₄CO₂NH₂(s) 2NH₃(g)  CO₂(g)

Correct Answer
verified

Correct Answer
verified
The burning of alkane gases and the free...
View Answer

Correct Answer
verified
Example from the text:
Graph ...
View Answer

Correct Answer
verified
A microstate is a unique distr...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

An ice cube at 0C melts in a swimming pool at 25C. What is the change in the entropy of the universe as a result? The ice cube was 2.00 inches on a side. Assume ice has a density of 0.917 g/cm³ and that the enthalpy of fusion of water is 6.01 kJ/mol.

Correct Answer
verified