Question 1

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

Accepted Answer

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

Question 2

a.Explain what is meant by a spontaneous process.
b.Is a spontaneous process necessarily a rapid one? Explain,and provide a real reaction as an example to illustrate your answer.

Accepted Answer

a.A spontaneous process is one which wil...

Question 3

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

Accepted Answer

A)  ΔS°rxn > 0,ΔH°rxn > 0
B)  ΔS°rxn > 0,ΔH°rxn 
C)  ΔS°rxn rxn 
D)  ΔS°rxn rxn > 0
E)  ΔS°rxn = 0,ΔH°rxn = 0F) B) and C)
G) A) and E)

Question 4

Which of these species has the highest entropy (S°) at 25°C?

Accepted Answer

A)  CH3OH(l) 
B)  CO(g) 
C)  MgCO3(s) 
D)  H2O(l) 
E)  Si(s) F) C) and D)
G) A) and C)

Question 5

The absolute standard entropy of atom X(g) is 100 J/K • mol.Which is a reasonable value for the absolute standard entropy of X2(g) ?

Accepted Answer

A)  200 J/K • mol
B)  170 J/K • mol
C)  100 J/K • mol
D)  80 J/K • mol
E)  50 J/K • molF) C) and D)
G) B) and C)

Question 6

Ozone (O3) in the atmosphere can react with nitric oxide (NO) as follows. O3(g) + NO(g) → NO2(g) + O2(g) .ΔH°rxn = -199 kJ/mol,ΔS°rxn = -4.1 J/K • mol
What is ΔG°rxn for this reaction at 25°C?

Accepted Answer

A)  1020 kJ/mol
B)  -1.22 × 103 kJ/mol
C)  2.00 × 103 kJ/mol
D)  -1.42 × 103 kJ/mol
E)  -198 kJ/molF) D) and E)
G) A) and B)

Question 7

Which is the thermodynamic condition for a spontaneous process at constant T and P?

Accepted Answer

A)  ΔS > 0
B)  ΔS 
C)  ΔG 
D)  ΔG > 0
E)  ΔG° = 0F) C) and D)
G) A) and B)

Question 8

HI has a normal boiling point of -35.4°C,and its ΔHvap is 21.16 kJ/mol.What is the molar entropy of vaporization (ΔSvap) of HI?

Accepted Answer

A)  598 J/K • mol
B)  68.6 J/K • mol
C)  75.2 J/K • mol
D)  0.068 J/K • mol
E)  89.0 J/K • molF) A) and B)
G) A) and C)

Question 9

Is the following process spontaneous?  0.  B) No,because ΔH  0. D) No,because ΔS

Accepted Answer

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

Question 10

Which is always true for an exothermic process?

Accepted Answer

A)  qsys > 0,ΔSsurr 
B)  qsys surr > 0
C)  qsys surr 
D)  qsys > 0,ΔSsurr > 0
E)  w < 0F) A) and D)
G) C) and E)

Question 11

Which of the following will decrease the entropy of an inert gas system?

Accepted Answer

A)  Increasing the temperature
B)  Decreasing the volume
C)  Adding a different inert gas to the system
D)  Increasing the molar mass
E)  Decreasing the pressureF) C) and E)
G) A) and D)

Question 12

Which species will have the greatest absolute entropy at 25°C?

Accepted Answer

A)  Ne(g) 
B)  C2H2(g) 
C)  H2O(l) 
D)  C2H5OH(l) 
E)  C4H10(g) F) C) and E)
G) B) and D)

Question 13

Which of the following results in a decrease in the entropy of the system?

Accepted Answer

A)  O2(g) ,300 K → O2(g) ,400 K
B)  H2O(s) ,0°C → H2O(l) ,0°C
C)  N2(g) ,25°C → N2(aq) ,25°C
D)  NH3(l) ,-34.5°C → NH3(g) ,-34.5°C
E)  2H2O2(g) → 2H2O(g) + O2(g) F) None of the above
G) D) and E)

Question 14

When a sky diver free-falls through the air,the process is

Accepted Answer

A)  nonspontaneous because he is accelerating due to the force applied by gravity.
B)  nonspontaneous because he is losing potential energy.
C)  nonspontaneous because he had planned the jump for two weeks.
D)  spontaneous.
E)  in equilibrium.F) A) and C)
G) C) and D)

Question 15

How many types of vibrations does a diatomic molecule exhibit?

Accepted Answer

A)  0
B)  1
C)  2
D)  3
E)  4F) A) and B)
G) C) and D)

Question 16

How many types of rotations does a diatomic molecule exhibit?

Accepted Answer

A)  0
B)  1
C)  2
D)  3
E)  4F) B) and C)
G) C) and E)

Question 17

A spontaneous endothermic reaction always

Accepted Answer

A)  causes the surroundings to get colder.
B)  bursts into flame.
C)  requires a spark to initiate it.
D)  releases heat to the surroundings.E) B) and C)
F) A) and D)

Question 18

For a chemical reaction to be spontaneous only at high temperatures,which conditions must be met?

Accepted Answer

A)  ΔS° > 0,ΔH° > 0
B)  ΔS° > 0,ΔH° 
C)  ΔS° 
D)  ΔS°  0
E)  ΔG° > 0F) A) and B)
G) C) and E)

Question 19

Which is necessary for a process to be spontaneous?

Accepted Answer

A)  ΔHsys 
B)  ΔSsys > 0
C)  ΔSsurr 
D)  ΔSuniv > 0
E)  ΔGsys = 0F) A) and E)
G) A) and D)

Question 20

Which has the largest entropy?

Accepted Answer

A)  C (diamond) 
B)  C (graphite) 
C)  H2O(l) 
D)  F2(l) 
E)  O2(g) F) All of the above
G) B) and C)

Exam 18: Entropy Free Energy and Equilibrium

A spontaneous endothermic reaction always

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Ozone (O3) in the atmosphere can react with nitric oxide (NO) as follows. O3(g) + NO(g) → NO2(g) + O2(g) .ΔH°rxn = -199 kJ/mol,ΔS°rxn = -4.1 J/K • mol What is ΔG°rxn for this reaction at 25°C?

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Which is always true for an exothermic process?

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

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Is the following process spontaneous?

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Which of the following will decrease the entropy of an inert gas system?

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How many types of vibrations does a diatomic molecule exhibit?

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When a sky diver free-falls through the air,the process is

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For a chemical reaction to be spontaneous only at high temperatures,which conditions must be met?

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

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Which of these species has the highest entropy (S°) at 25°C?

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Which is necessary for a process to be spontaneous?

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Which has the largest entropy?

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Which is the thermodynamic condition for a spontaneous process at constant T and P?

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Which species will have the greatest absolute entropy at 25°C?

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The absolute standard entropy of atom X(g) is 100 J/K • mol.Which is a reasonable value for the absolute standard entropy of X2(g) ?

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a.Explain what is meant by a spontaneous process. b.Is a spontaneous process necessarily a rapid one? Explain,and provide a real reaction as an example to illustrate your answer.

Correct Answerverifieda.A spontaneous process is one which wil...View AnswerShow Answer

How many types of rotations does a diatomic molecule exhibit?

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Which of the following results in a decrease in the entropy of the system?

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HI has a normal boiling point of -35.4°C,and its ΔHvap is 21.16 kJ/mol.What is the molar entropy of vaporization (ΔSvap) of HI?

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Ozone (O₃) in the atmosphere can react with nitric oxide (NO) as follows. O₃(g) + NO(g) → NO₂(g) + O₂(g) .ΔH°_rxn = -199 kJ/mol,ΔS°_rxn = -4.1 J/K • mol What is ΔG°_rxn for this reaction at 25°C?

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The absolute standard entropy of atom X(g) is 100 J/K • mol.Which is a reasonable value for the absolute standard entropy of X₂(g) ?

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a.A spontaneous process is one which wil...
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HI has a normal boiling point of -35.4°C,and its ΔH_vap is 21.16 kJ/mol.What is the molar entropy of vaporization (ΔS_vap) of HI?

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