Question 1

Elemental boron can be formed by reaction of boron trichloride with hydrogen.
BCl3(g) + 1.5H2(g)   →	o→  B(s) + 3HCl(g) 
3(g) + 1.5H2(g)   	o  B(s) + 3HCl(g)    If  \Delta S° = 80.3 J/K,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  Δ\DeltaΔ S° = 80.3 J/K,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·mol F) All of the above
G) B) and E)

Question 2

Which of the following is always true for an exothermic process?

Accepted Answer

A)  qsys > 0, Δ\DeltaΔ Ssurr 
B)  qsys Δ\DeltaΔ Ssurr > 0
C)  qsys Δ\DeltaΔ Ssurr 
D)  qsys > 0, Δ\DeltaΔ Ssurr > 0
E)  w < 0 F) All of the above
G) B) and D)

Question 3

Which relationship or statement best describes  Δ\DeltaΔ S° for the following reaction?
C2H5OH(l) + 3O2(g)   →	o→  2CO2(g) + 3H2O(l)

Accepted Answer

A)  ( Δ\DeltaΔ S°  ≈\approx≈  0) 
B)  ( Δ\DeltaΔ S° 
C)  ( Δ\DeltaΔ S° > 0) 
D)  ( Δ\DeltaΔ S° =  Δ\DeltaΔ H°/T) 
E)  More information is needed to make a reasonable prediction. F) B) and E)
G) C) and E)

Question 4

In which one of the following pairs will the first system have a higher entropy than the second? Assume P and T are the same for each pair,unless stated otherwise.

Accepted Answer

A)  1 mole He(g) ;1 mole Kr(g) 
B)  1 mole O2(g) ;2 mole O(g) 
C)  1 mole CH4(g) ;1 mole C2H6(g) 
D)  1 mole Xe(g) at 1 atmosphere;1 mole Xe(g) at 0.5 atmosphere
E)  20 one-dollar bills distributed randomly among 20 people;20 one-dollar bills distributed randomly among 10 peopleF) None of the above
G) B) and E)

Question 5

You are given pure samples of pentane,CH3CH2CH2CH2CH3(l) ,and 1,3-pentadiene,CH2=CHCH=CHCH3(l) .What prediction would you make concerning the standard molar entropies of pentane,S°(pentane) and 1,3-pentadiene,S°(1,3-pentadiene) ,at 298 K?

Accepted Answer

A)  S°(pentane) > S°(1,3-pentadiene) 
B)  S°(pentane) 
C)  S°(pentane)   ≈\approx≈  S°(1,3-pentadiene) 
D)  S°(pentane) = S°(1,3-pentadiene) + 2  ×	imes×  S°(H2) 
E)  More information is needed to make reasonable predictions. F) B) and D)
G) C) and D)

Question 6

A chemical reaction has $\Delta$G° = 10.0 kJ and $\Delta$S° = 50.0 J/K
a.Calculate $\Delta$H° for this reaction at 25°C.
b.Could this reaction ever be spontaneous? Explain your answer.

Accepted Answer

a.

H° = 24.9 kJ
b.Yes.Assuming ...

Question 7

The term microstate refers to the energy state of a single molecule in a system of many molecules.

Accepted Answer

A) True 
 B)False

Question 8

Given: C2H2(g)$\to$ 2C(graphite)+ H2(g)$\Delta$G° = -209 kJ
A sample of gaseous C2H2 (acetylene,or ethyne)was stored for one year,yet at the end of this period the sample remained unchanged and no graphite or hydrogen gas had been formed.Briefly explain why there is no inconsistency between the sign of $\Delta$G° and the apparent stability of the sample.

Accepted Answer

Relative to graphite and hydrogen,acetyl...

Question 9

Which relationship or statement best describes  Δ\DeltaΔ S° for the following reaction?
2NH3(g) + 2ClF3(g)   →	o→  6HF(g) + N2(g) + Cl2(g)

Accepted Answer

A)  ( Δ\DeltaΔ S°  ≈\approx≈  0) 
B)  ( Δ\DeltaΔ S° 
C)  ( Δ\DeltaΔ S° > 0) 
D)  ( Δ\DeltaΔ S° =  Δ\DeltaΔ H°/T) 
E)  More information is needed to make a reasonable prediction. F) A) and B)
G) A) and C)

Question 10

Under a given set of conditions,all microstates of a system are equally probable.

Accepted Answer

A) True 
 B)False

Question 11

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.
CH4(g) + 2H2O(g)  4(g) + 2H2O(g)    CO2(g) + 4H2(g)    A) 658 K B) 683 K C) 955 K D) 1047 K E) 1229 K" class="answers-bank-image d-inline" rel="preload" >
CO2(g) + 4H2(g) 
4(g) + 2H2O(g)    CO2(g) + 4H2(g)    A) 658 K B) 683 K C) 955 K D) 1047 K E) 1229 K" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

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

Question 12

For a chemical reaction to be spontaneous at all temperatures,which of the following conditions must be met?

Accepted Answer

A)  ( Δ\DeltaΔ S° > 0, Δ\DeltaΔ H° > 0) 
B)  ( Δ\DeltaΔ S° > 0, Δ\DeltaΔ H° 
C)  ( Δ\DeltaΔ S° Δ\DeltaΔ H° 
D)  ( Δ\DeltaΔ S° Δ\DeltaΔ H° > 0) 
E)  (It is not possible for a reaction to be spontaneous at all temperatures. F) D) and E)
G) C) and D)

Question 13

The complete combustion of liquid benzene is represented by the equation:
C6H6(l)+ 7  
O2(g) $\to$ 6CO2(g)+ 3H2O(l)
Using the data below,calculate,for this reaction
a.$\Delta$H°
b.$\Delta$S°
c.$\Delta$G° at 25°C.

Accepted Answer

a.<img  loading="lazy" src="/assets/images/blured-textbook.svg" class="d-inline m-1" alt="blured image" width="139" height="30">H° = -32...

Question 14

Calculate  Δ\DeltaΔ S° for the reaction
2Cl2(g) + SO2(g)   →	o→ SOCl2(g) + Cl2O(g) 
2(g) + SO2(g)   	o SOCl2(g) + Cl2O(g)    A) -118.2 J/K B) -104.8 J/K C) 104.8 J/K D) 118.2 J/K E) 1270.0 J/K " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  -118.2 J/K
B)  -104.8 J/K
C)  104.8 J/K
D)  118.2 J/K
E)  1270.0 J/K F) B) and E)
G) A) and B)

Question 15

What is the free energy change, ∘\circ∘ G°,for the equilibrium between hydrogen iodide,hydrogen,and iodine at 453°C? Kc = 0.020
2HI(g)   \circ G°,for the equilibrium between hydrogen iodide,hydrogen,and iodine at 453°C? Kc = 0.020 2HI(g)    H2(g) + I2(g)  A) 6.4 kJ B) 8.8 kJ C) 15 kJ D) 19 kJ E) 24 kJ " class="answers-bank-image d-inline" rel="preload" >
H2(g) + I2(g)

Accepted Answer

A)  6.4 kJ
B)  8.8 kJ
C)  15 kJ
D)  19 kJ
E)  24 kJ F) All of the above
G) A) and B)

Question 16

The formation constant for the reaction
Ag+(aq) + 2NH3(aq)  +(aq) + 2NH3(aq)    Ag(NH3) 2+(aq)  Is Kf = 1.7  	imes  107 at 25°C.What is  \Delta G° at this temperature? A) -1.5 kJ B) -3.5 kJ C) -18 kJ D) -23 kJ E) -41 kJ " class="answers-bank-image d-inline" rel="preload" >
Ag(NH3) 2+(aq) 
Is Kf = 1.7  ×	imes×  107 at 25°C.What is  Δ\DeltaΔ G° at this temperature?

Accepted Answer

A)  -1.5 kJ
B)  -3.5 kJ
C)  -18 kJ
D)  -23 kJ
E)  -41 kJ F) A) and D)
G) B) and D)

Question 17

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 sta...

Question 18

Iron(III) oxide can be reduced by carbon monoxide.
Fe2O3(s) + 3CO(g)  2O3(s) + 3CO(g)    2Fe(s) + 3CO2(g)  Use the following thermodynamic data at 298 K to determine the equilibrium constant at this temperature.   A) 7.0  	imes  10-6 B) 1.3  	imes  10-3 C) 2.2  	imes  104 D) 1.4  	imes  105 E)  > 2.0  	imes  105 " class="answers-bank-image d-inline" rel="preload" >
2Fe(s) + 3CO2(g) 
Use the following thermodynamic data at 298 K to determine the equilibrium constant at this temperature.
2O3(s) + 3CO(g)    2Fe(s) + 3CO2(g)  Use the following thermodynamic data at 298 K to determine the equilibrium constant at this temperature.   A) 7.0  	imes  10-6 B) 1.3  	imes  10-3 C) 2.2  	imes  104 D) 1.4  	imes  105 E)  > 2.0  	imes  105 " class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  7.0  ×	imes×  10-6
B)  1.3  ×	imes×  10-3
C)  2.2  ×	imes×  104
D)  1.4  ×	imes×  105
E)   > 2.0  ×	imes×  105 F) All of the above
G) D) and E)

Question 19

Which relationship best describes  Δ\DeltaΔ S° for the following reaction?
CO(g) + H2O(g)   →	o→  CO2(g) + H2(g)

Accepted Answer

A)  ( Δ\DeltaΔ S° =  Δ\DeltaΔ H°) 
B)  (F Δ\DeltaΔ S° =  Δ\DeltaΔ H°/T) 
C)  ( Δ\DeltaΔ S° > 0) 
D)  ( Δ\DeltaΔ S° 
E)  ( Δ\DeltaΔ S°  ≈\approx≈  0)  F) A) and E)
G) None of the above

Question 20

For each of the following pairs,predict which (A or B)will have the greater entropy,and in one sentence indicate your reasoning.

Accepted Answer

a.A has greater entropy.HI and HBr are c...

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

In which one of the following pairs will the first system have a higher entropy than the second? Assume P and T are the same for each pair,unless stated otherwise.

Correct Answer
verified

A chemical reaction has $\Delta$ G° = 10.0 kJ and $\Delta$ S° = 50.0 J/K a.Calculate $\Delta$ H° for this reaction at 25°C. b.Could this reaction ever be spontaneous? Explain your answer.

Correct Answer
verified
a.H° = 24.9 kJ
b.Yes.Assuming ...
View Answer

Correct Answer
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Correct Answer
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Relative to graphite and hydrogen,acetyl...
View Answer

The term microstate refers to the energy state of a single molecule in a system of many molecules.

Correct Answer
verified

Correct Answer
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Which of the following is always true for an exothermic process?

Correct Answer
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Correct Answer
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Which relationship best describes $\Delta$ S° for the following reaction? CO(g) + H₂O(g) $\to$ CO₂(g) + H₂(g)

Correct Answer
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You are given pure samples of pentane,CH₃CH₂CH₂CH₂CH₃(l) ,and 1,3-pentadiene,CH₂=CHCH=CHCH₃(l) .What prediction would you make concerning the standard molar entropies of pentane,S°(pentane) and 1,3-pentadiene,S°(1,3-pentadiene) ,at 298 K?

Correct Answer
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For a chemical reaction to be spontaneous at all temperatures,which of the following conditions must be met?

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

Correct Answer
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Which relationship or statement best describes $\Delta$ S° for the following reaction? C₂H₅OH(l) + 3O₂(g) $\to$ 2CO₂(g) + 3H₂O(l)

Correct Answer
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Correct Answer
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a.H° = -32...
View Answer

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. CH₄(g) + 2H₂O(g) CO₂(g) + 4H₂(g)

Correct Answer
verified

Calculate $\Delta$ S° for the reaction 2Cl₂(g) + SO₂(g) $\to$ SOCl₂(g) + Cl₂O(g) $Calculate \Delta S° for the reaction 2Cl<sub>2</sub>(g) + SO<sub>2</sub>(g) \to SOCl<sub>2</sub>(g) + Cl<sub>2</sub>O(g) A) -118.2 J/K B) -104.8 J/K C) 104.8 J/K D) 118.2 J/K E) 1270.0 J/K$

Correct Answer
verified

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 Answer
verified
A microstate is a specific,quantized sta...
View Answer

Under a given set of conditions,all microstates of a system are equally probable.

Correct Answer
verified

For each of the following pairs,predict which (A or B)will have the greater entropy,and in one sentence indicate your reasoning.

Correct Answer
verified
a.A has greater entropy.HI and HBr are c...
View Answer

Correct Answer
verified

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

In which one of the following pairs will the first system have a higher entropy than the second? Assume P and T are the same for each pair,unless stated otherwise.

Correct AnswerverifiedShow Answer

A chemical reaction has Δ\DeltaΔ G° = 10.0 kJ and Δ\DeltaΔ S° = 50.0 J/K a.Calculate Δ\DeltaΔ H° for this reaction at 25°C. b.Could this reaction ever be spontaneous? Explain your answer.

Correct Answerverifieda.H° = 24.9 kJb.Yes.Assuming ...View AnswerShow Answer

What is the free energy change, ∘\circ∘ G°,for the equilibrium between hydrogen iodide,hydrogen,and iodine at 453°C? Kc = 0.020 2HI(g) H2(g) + I2(g)

Correct AnswerverifiedShow Answer

Correct AnswerverifiedRelative to graphite and hydrogen,acetyl...View AnswerShow Answer

The term microstate refers to the energy state of a single molecule in a system of many molecules.

Correct AnswerverifiedShow Answer

The formation constant for the reaction Ag+(aq) + 2NH3(aq) Ag(NH3) 2+(aq) Is Kf = 1.7 ×\times× 107 at 25°C.What is Δ\DeltaΔ G° at this temperature?

Correct AnswerverifiedShow Answer

Which of the following is always true for an exothermic process?

Correct AnswerverifiedShow Answer

Elemental boron can be formed by reaction of boron trichloride with hydrogen. BCl3(g) + 1.5H2(g) →\to→ B(s) + 3HCl(g) If Δ\DeltaΔ S° = 80.3 J/K,what is S° for BCl3(g) ?

Correct AnswerverifiedShow Answer

Which relationship best describes Δ\DeltaΔ S° for the following reaction? CO(g) + H2O(g) →\to→ CO2(g) + H2(g)

Correct AnswerverifiedShow Answer

You are given pure samples of pentane,CH3CH2CH2CH2CH3(l) ,and 1,3-pentadiene,CH2=CHCH=CHCH3(l) .What prediction would you make concerning the standard molar entropies of pentane,S°(pentane) and 1,3-pentadiene,S°(1,3-pentadiene) ,at 298 K?

Correct AnswerverifiedShow Answer

For a chemical reaction to be spontaneous at all temperatures,which of the following conditions must be met?

Correct AnswerverifiedShow Answer

Which relationship or statement best describes Δ\DeltaΔ S° for the following reaction? 2NH3(g) + 2ClF3(g) →\to→ 6HF(g) + N2(g) + Cl2(g)

Correct AnswerverifiedShow Answer

Which relationship or statement best describes Δ\DeltaΔ S° for the following reaction? C2H5OH(l) + 3O2(g) →\to→ 2CO2(g) + 3H2O(l)

Correct AnswerverifiedShow Answer

The complete combustion of liquid benzene is represented by the equation: C6H6(l)+ 7 O2(g) →\to→ 6CO2(g)+ 3H2O(l) Using the data below,calculate,for this reaction a. Δ\DeltaΔ H° b. Δ\DeltaΔ S° c. Δ\DeltaΔ G° at 25°C.

Correct Answerverifieda.H° = -32...View AnswerShow Answer

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. CH4(g) + 2H2O(g) CO2(g) + 4H2(g)

Correct AnswerverifiedShow Answer

Calculate Δ\DeltaΔ S° for the reaction 2Cl2(g) + SO2(g) →\to→ SOCl2(g) + Cl2O(g)

Correct AnswerverifiedShow Answer

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 sta...View AnswerShow Answer

Under a given set of conditions,all microstates of a system are equally probable.

Correct AnswerverifiedShow Answer

For each of the following pairs,predict which (A or B)will have the greater entropy,and in one sentence indicate your reasoning.

Correct Answerverifieda.A has greater entropy.HI and HBr are c...View AnswerShow Answer

Iron(III) oxide can be reduced by carbon monoxide. Fe2O3(s) + 3CO(g) 2Fe(s) + 3CO2(g) Use the following thermodynamic data at 298 K to determine the equilibrium constant at this temperature.

Correct AnswerverifiedShow Answer

Correct Answer
verified

A chemical reaction has $\Delta$ G° = 10.0 kJ and $\Delta$ S° = 50.0 J/K a.Calculate $\Delta$ H° for this reaction at 25°C. b.Could this reaction ever be spontaneous? Explain your answer.

Correct Answer
verified
a.H° = 24.9 kJ
b.Yes.Assuming ...
View Answer

Correct Answer
verified

Correct Answer
verified
Relative to graphite and hydrogen,acetyl...
View Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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Which relationship best describes $\Delta$ S° for the following reaction? CO(g) + H₂O(g) $\to$ CO₂(g) + H₂(g)

Correct Answer
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You are given pure samples of pentane,CH₃CH₂CH₂CH₂CH₃(l) ,and 1,3-pentadiene,CH₂=CHCH=CHCH₃(l) .What prediction would you make concerning the standard molar entropies of pentane,S°(pentane) and 1,3-pentadiene,S°(1,3-pentadiene) ,at 298 K?

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

Correct Answer
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Which relationship or statement best describes $\Delta$ S° for the following reaction? C₂H₅OH(l) + 3O₂(g) $\to$ 2CO₂(g) + 3H₂O(l)

Correct Answer
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Correct Answer
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a.H° = -32...
View Answer

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. CH₄(g) + 2H₂O(g) CO₂(g) + 4H₂(g)

Correct Answer
verified

Calculate $\Delta$ S° for the reaction 2Cl₂(g) + SO₂(g) $\to$ SOCl₂(g) + Cl₂O(g) $Calculate \Delta S° for the reaction 2Cl<sub>2</sub>(g) + SO<sub>2</sub>(g) \to SOCl<sub>2</sub>(g) + Cl<sub>2</sub>O(g) A) -118.2 J/K B) -104.8 J/K C) 104.8 J/K D) 118.2 J/K E) 1270.0 J/K$

Correct Answer
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Correct Answer
verified
A microstate is a specific,quantized sta...
View Answer

Correct Answer
verified

Correct Answer
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a.A has greater entropy.HI and HBr are c...
View Answer

Correct Answer
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