Question 1

Consider the reaction 
11ec6d53_97e1_49fd_9cd1_030bf8888a28_TB5833_
If the concentrations of the Cu+ and I- ions in equilibrium at 298 K are both equal to 1.03 × 10-6 M, what is the value of G° for the reaction?

Accepted Answer

A)   -68 kJ
B)   68 kJ
C)   -30. kJ
D)   30 kJ
E)   34 kJF) None of the above
G) C) and D)

Question 2

Sulfuryl dichloride is formed when sulfur dioxide reacts with chlorine. The data refer to 298 K. SO2(g)  + Cl2(g)   SO2Cl2(g)  2(g)  + Cl2(g)   SO2Cl2(g)    What is the value of G° for this reaction at 600 K? A)  -162.8 kJ B)  -40.1 kJ C)  -28.4 kJ D)  28.4 kJ E)  162.8 kJ" class="answers-bank-image d-inline" rel="preload" > What is the value of G° for this reaction at 600 K?

Accepted Answer

A)   -162.8 kJ
B)   -40.1 kJ
C)   -28.4 kJ
D)   28.4 kJ
E)   162.8 kJF) None of the above
G) A) and C)

Question 3

Which of the following is true for pure oxygen gas, O2(g)  at 25°C?

Accepted Answer

A)   .H° f > 0
B)   .H° f 
C)   .G° f > 0
D)   .G° f 
E)   S° > 0F) A) and B)
G) D) and E)

Question 4

In order for a process to be spontaneous,

Accepted Answer

A)   the entropy of the system must increase.
B)   the entropy of the surroundings must increase.
C)   the entropy of the universe must decrease.
D)   the entropy of the surroundings must decrease.
E)   the entropy change of the surroundings plus the entropy change of the system must be positive.F) A) and C)
G) All of the above

Question 5

Which of the following is necessary for a process to be spontaneous?

Accepted Answer

A)   .Hsys 
B)   .Ssys > 0
C)   .Ssurr
D)   .Suniv > 0
E)   .Gsys = 0F) B) and C)
G) B) and D)

Question 6

Elemental boron can be formed by reaction of boron trichloride with hydrogen. S° = 80.3 J/K for the reaction above, what is S° for BCl3(g) ? A)  -18.2 J/Kmol B)  18.2 J/Kmol C)  290.1 J/Kmol D)  355.4 J/Kmol E)  450.6 J/Kmol" class="answers-bank-image d-inline" rel="preload" > If S° = 80.3 J/K for the reaction above, what is S° for BCl3(g) ?

Accepted Answer

A)   -18.2 J/Kmol
B)   18.2 J/Kmol
C)   290.1 J/Kmol
D)   355.4 J/Kmol
E)   450.6 J/KmolF) B) and E)
G) A) and B)

Question 7

Which relationship or statement best describes S° for the following reaction? 
2NH3(g)  + 2ClF3(g)   6HF(g)  + N2(g)  + Cl2(g)

Accepted Answer

A)   .S°   0
B)   .S° 
C)   .S° > 0
D)   .S° = H°/T
E)   More information is needed to make a reasonable prediction.F) D) and E)
G) None of the above

Question 8

In the expression, S = k ln W, W is called the number of microstates. Explain clearly the meaning of the word "microstate", and why a system under a given set of conditions normally has many microstates.

Accepted Answer

A microstate is a specific, quantized st...

Question 9

The higher the pressure of a gas sample, the greater is its entropy.

Accepted Answer

A) True 
 B)False

Question 10

The reaction of methane with water to form carbon dioxide and hydrogen is non-spontaneous at 298 K. At what temperature will this system make the transition from non-spontaneous to spontaneous? The data refer to 298 K.

Accepted Answer

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

Question 11

In which one of these pairs will the entropy of the first substance be greater than that of the second? Assume P and T are the same for each pair, unless stated otherwise.

Accepted Answer

A)   1 mole of F2(g) ; 1 mole of Cl2(g) 
B)   1 mole of I2(s) ; 1 mole of I2(g) 
C)   1 mole of CaCO3(s) ; 1 mole of CaO(s)  plus 1 mole of CO2(g) 
D)   1 mole of H2(g)  at 25°C; 1 mole of H2(g)  at 50°C
E)   1 mole of O3(g) ; 1 mole of O2(g) F) A) and B)
G) A) and C)

Question 12

Consider the figure which shows G° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that: G° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that:   A)  .H° > 0, S° > 0 B)  .H° > 0, S° H° S° > 0 D)  .H° S°

Accepted Answer

A)   .H° > 0, S° > 0
B)   .H° > 0, S° 
C)   .H° S° > 0
D)   .H° S° 
E)   none of the aboveF) B) and D)
G) C) and E)

Question 13

Given: H2O(l)   H2O(s)  H° = -6.02 kJ at 273K Calculate the entropy change of the surroundings (Ssurr)  when one mole of water freezes at 0 °C and a pressure of one atmosphere.

Accepted Answer

A)   22.1 J/K
B)   -22.1 J/K
C)   397 J/K
D)   -397 J/K
E)   0.022 J/KF) None of the above
G) A) and D)

Question 14

For what signs of F1F1F1S1F1F1F10H and F1F1F1S1F1F1F10S will a process
a. be spontaneous at high temperatures but not at low temperatures?
b. not be spontaneous at any temperatures?

Accepted Answer

a. <font face="symbol"></font>H...

Question 15

Which relationship best describes S° for the following reaction? 8H2(g)  + S8(s)   8H2S(g)

Accepted Answer

A)   .S° = H°
B)   .S° = H°/T
C)   .S°  0
D)   .S° 
E)   .S° > 0F) A) and E)
G) B) and E)

Question 16

Use the given data at 298 K to calculate G° for the reaction G° for the reaction   A)  129.3 kJ B)  133.6 kJ C)  196.0 kJ D)  199.8 kJ E)  229.6 kJ" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   129.3 kJ
B)   133.6 kJ
C)   196.0 kJ
D)   199.8 kJ
E)   229.6 kJF) A) and D)
G) C) and E)

Question 17

Consider the figure which shows G° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that: G° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that:   A)  .H° > 0, S° > 0 B)  .H° > 0, S° H° S° > 0 D)  .H° S°

Accepted Answer

A)   .H° > 0, S° > 0
B)   .H° > 0, S° 
C)   .H° S° > 0
D)   .H° S° 
E)   none of the aboveF) A) and D)
G) B) and E)

Question 18

For any reaction, if F1F1F1S1F1F1F10G° > 0, then K < 1.

Accepted Answer

A) True 
 B)False

Question 19

Which relationship or statement best describes S° for the following reaction? BaCl2(aq)  + Na2SO4(aq)   BaSO4(s)  + 2NaCl(aq)

Accepted Answer

A)   .S°  0
B)   .S° 
C)   .S° > 0
D)   .S° = H°/T
E)   More information is needed to make a reasonable prediction.F) A) and D)
G) None of the above

Question 20

In order for a process to be spontaneous,

Accepted Answer

A)   .H must be less than zero.
B)   .S must be greater than zero.
C)   .G must be greater than zero.
D)   it should be rapid.
E)   .Ssys + Ssurr  must be greater than zero.F) A) and B)
G) A) and C)

Exam 20: Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions

The reaction of methane with water to form carbon dioxide and hydrogen is non-spontaneous at 298 K. At what temperature will this system make the transition from non-spontaneous to spontaneous? The data refer to 298 K.

Correct AnswerverifiedShow Answer

Elemental boron can be formed by reaction of boron trichloride with hydrogen. If S° = 80.3 J/K for the reaction above, what is S° for BCl3(g) ?

Correct AnswerverifiedShow Answer

Given: H2O(l)  H2O(s) H° = -6.02 kJ at 273K Calculate the entropy change of the surroundings (Ssurr) when one mole of water freezes at 0 °C and a pressure of one atmosphere.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

In order for a process to be spontaneous,

Correct AnswerverifiedShow Answer

Which of the following is true for pure oxygen gas, O2(g) at 25°C?

Correct AnswerverifiedShow Answer

Which of the following is necessary for a process to be spontaneous?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Which relationship or statement best describes S° for the following reaction? BaCl2(aq) + Na2SO4(aq)  BaSO4(s) + 2NaCl(aq)

Correct AnswerverifiedShow Answer

In which one of these pairs will the entropy of the first substance be greater than that of the second? Assume P and T are the same for each pair, unless stated otherwise.

Correct AnswerverifiedShow Answer

Use the given data at 298 K to calculate G° for the reaction

Correct AnswerverifiedShow Answer

The higher the pressure of a gas sample, the greater is its entropy.

Correct AnswerverifiedShow Answer

For what signs of H and S will a process a. be spontaneous at high temperatures but not at low temperatures? b. not be spontaneous at any temperatures?

Correct Answerverifieda. H...View AnswerShow Answer

Consider the reaction 11ec6d53_97e1_49fd_9cd1_030bf8888a28_TB5833_ If the concentrations of the Cu+ and I- ions in equilibrium at 298 K are both equal to 1.03 × 10-6 M, what is the value of G° for the reaction?

Correct AnswerverifiedShow Answer

Which relationship best describes S° for the following reaction? 8H2(g) + S8(s)  8H2S(g)

Correct AnswerverifiedShow Answer

For any reaction, if G° > 0, then K < 1.

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In the expression, S = k ln W, W is called the number of microstates. Explain clearly the meaning of the word "microstate", and why a system under a given set of conditions normally has many microstates.

Correct AnswerverifiedA microstate is a specific, quantized st...View AnswerShow Answer

Sulfuryl dichloride is formed when sulfur dioxide reacts with chlorine. The data refer to 298 K. SO2(g) + Cl2(g)  SO2Cl2(g) What is the value of G° for this reaction at 600 K?

Correct AnswerverifiedShow Answer

Which relationship or statement best describes S° for the following reaction? 2NH3(g) + 2ClF3(g)  6HF(g) + N2(g) + Cl2(g)

Correct AnswerverifiedShow Answer

In order for a process to be spontaneous,

Correct AnswerverifiedShow Answer

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Elemental boron can be formed by reaction of boron trichloride with hydrogen. If S° = 80.3 J/K for the reaction above, what is S° for BCl₃(g) ?

Correct Answer
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Given: H₂O(l)  H₂O(s) H° = -6.02 kJ at 273K Calculate the entropy change of the surroundings (S_surr) when one mole of water freezes at 0 °C and a pressure of one atmosphere.

Correct Answer
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Which of the following is true for pure oxygen gas, O₂(g) at 25°C?

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Which relationship or statement best describes S° for the following reaction? BaCl₂(aq) + Na₂SO₄(aq)  BaSO₄(s) + 2NaCl(aq)

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a. H...
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Consider the reaction 11ec6d53_97e1_49fd_9cd1_030bf8888a28_TB5833_ If the concentrations of the Cu⁺ and I^- ions in equilibrium at 298 K are both equal to 1.03 × 10^-6 M, what is the value of G° for the reaction?

Correct Answer
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Which relationship best describes S° for the following reaction? 8H₂(g) + S₈(s)  8H₂S(g)

Correct Answer
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A microstate is a specific, quantized st...
View Answer

Sulfuryl dichloride is formed when sulfur dioxide reacts with chlorine. The data refer to 298 K. SO₂(g) + Cl₂(g)  SO₂Cl₂(g) What is the value of G° for this reaction at 600 K?

Correct Answer
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Which relationship or statement best describes S° for the following reaction? 2NH₃(g) + 2ClF₃(g)  6HF(g) + N₂(g) + Cl₂(g)

Correct Answer
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Correct Answer
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