Question 1

Which of the following processes have a ΔrS > 0?

Accepted Answer

A)  CH3OH(l) → CH3OH(s) 
B)  N2(g) + 3H2(g) → 2NH3(g) 
C)  CH4(g) + H2O (g) → CO(g) + 3H2(g) 
D)  Na2CO3(s) + H2O(g) + CO2(g) → 2NaHCO3(s) 
E)  H2O(g) → H2O(l) F) D) and E)
G) C) and D)

Question 2

Which one of the following has the highest standard molar entropy, S°, at 25 °C?

Accepted Answer

A)  I2(g) 
B)  F2(g) 
C)  Br2(l) 
D)  N2(g) 
E)  Cl2(g) F) B) and E)
G) A) and D)

Question 3

Choose the statement below that is TRUE.

Accepted Answer

A)  If K > 1, ΔrG for forward reaction is positive.
B)  If K rG for forward reaction is negative.
C)  If K > 1, ΔrG for reverse reaction is negative.
D)  ΔrG = 0 at equilibrium.
E)  If K rG for reverse reaction is positive.F) A) and E)
G) D) and E)

Question 4

Calculate ΔrG at 298 K under the conditions shown below for the following reaction: Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g) ΔG° = -28.0 kJ mol-1
P(CO) = 1.4 atm, P(CO2) = 2.1 atm

Accepted Answer

A)  +31.0 kJ mol-1
B)  +2.99 kJ mol-1
C)  -30.7 kJ mol-1
D)  +17.5 kJ mol-1
E)  -25.0 kJ mol-1F) C) and D)
G) B) and E)

Question 5

Define the second law of thermodynamics.

Accepted Answer

For any spontaneous ...

Question 6

Use Hess's law to calculate ΔrG° using the following information: NO(g) + O(g) → NO2(g) ΔrG° = ?
2O3(g) → 3O2(g) ΔrG° = +489.6 kJ mol-1
O2(g) → 2O(g) ΔrG° = +463.4 kJ mol-1
NO(g) + O3(g) → NO2(g) + O2(g) ΔrG° = - 199.5 kJ mol-1

Accepted Answer

A)  +753.5 kJ mol-1
B)  +277.0 kJ mol-1
C)  -676.0 kJ mol-1
D)  -1152.5 kJ mol-1
E)  -225.7 kJ mol-1F) B) and C)
G) C) and D)

Question 7

Consider a reaction that has a positive ΔrH and a positive ΔrS. Which of the following statements is TRUE?

Accepted Answer

A)  This reaction will be spontaneous only at high temperatures.
B)  This reaction will be spontaneous at all temperatures.
C)  This reaction will be nonspontaneous at all temperatures.
D)  This reaction will be nonspontaneous only at high temperatures.
E)  This reaction will be spontaneous only at very low temperatures.F) A) and B)
G) C) and D)

Question 8

Which of the following is TRUE if ln K is zero?

Accepted Answer

A)  ΔrG° is positive and the reaction is spontaneous in the forward direction.
B)  ΔrG° is negative and the reaction is spontaneous in the forward direction.
C)  ΔrG° is negative and the reaction is spontaneous in the reverse direction.
D)  ΔrG° is positive and the reaction is spontaneous in the reverse direction.
E)  ΔrG° is zero and the reaction is at equilibrium.F) A) and E)
G) B) and D)

Question 9

Which of the following relationships is correct at constant T and P?

Accepted Answer

A)  ΔrG is proportional to -ΔSuniv.
B)  ΔrG > 0 represents a spontaneous process.
C)  ΔrG > 0 represents an increase in kinetic energy.
D)  ΔrG 
E)  ΔrG is not a function of temperature.F) C) and D)
G) B) and C)

Question 10

Consider a reaction that has a positive ΔrH and a negative ΔrS. Which of the following statements is TRUE?

Accepted Answer

A)  This reaction will be spontaneous only at high temperatures.
B)  This reaction will be spontaneous at all temperatures.
C)  This reaction will be nonspontaneous at all temperatures.
D)  This reaction will be nonspontaneous only at high temperatures.
E)  This reaction will be spontaneous only at absolute zero (0 Kelvin) .F) D) and E)
G) A) and C)

Question 11

Given the following equation, N2O(g) + NO2(g) → 3NO(g) ΔrG° = -23.0 kJ mol-1
Calculate ΔrG° for the following reaction:
3N2O(g) + 3NO2(g) → 9NO(g)

Accepted Answer

A)  -23.0 kJ mol-1
B)  69.0 kJ mol-1
C)  -69.0 kJ mol-1
D)  -7.67 kJ mol-1
E)  23.0 kJ mol-1F) D) and E)
G) A) and D)

Exam 17: Gibbs Energy and Thermodynamics

Which one of the following has the highest standard molar entropy, S°, at 25 °C?

Correct Answer
verified

Calculate Δ_rG at 298 K under the conditions shown below for the following reaction: Fe₂O₃(s) + 3CO(g) → 2Fe(s) + 3CO₂(g) ΔG° = -28.0 kJ mol^-1 P(CO) = 1.4 atm, P(CO₂) = 2.1 atm

Correct Answer
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Use Hess's law to calculate Δ_rG° using the following information: NO(g) + O(g) → NO₂(g) Δ_rG°= ? 2O₃(g) → 3O₂(g) Δ_rG°= +489.6 kJ mol^-1 O₂(g) → 2O(g) Δ_rG°= +463.4 kJ mol^-1 NO(g) + O₃(g) → NO₂(g) + O₂(g) Δ_rG°= - 199.5 kJ mol^-1

Correct Answer
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Which of the following processes have a Δ_rS > 0?

Correct Answer
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Consider a reaction that has a positive Δ_rH and a negative Δ_rS. Which of the following statements is TRUE?

Correct Answer
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Which of the following relationships is correct at constant T and P?

Correct Answer
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Define the second law of thermodynamics.

Correct Answer
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For any spontaneous ...
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Consider a reaction that has a positive Δ_rH and a positive Δ_rS. Which of the following statements is TRUE?

Correct Answer
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Choose the statement below that is TRUE.

Correct Answer
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Which of the following is TRUE if ln K is zero?

Correct Answer
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Given the following equation, N₂O(g) + NO₂(g) → 3NO(g) Δ_rG° = -23.0 kJ mol^-1 Calculate Δ_rG° for the following reaction: 3N₂O(g) + 3NO₂(g) → 9NO(g)

Correct Answer
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Exam 17: Gibbs Energy and Thermodynamics

Which one of the following has the highest standard molar entropy, S°, at 25 °C?

Correct AnswerverifiedShow Answer

Calculate ΔrG at 298 K under the conditions shown below for the following reaction: Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g) ΔG° = -28.0 kJ mol-1 P(CO) = 1.4 atm, P(CO2) = 2.1 atm

Correct AnswerverifiedShow Answer

Use Hess's law to calculate ΔrG° using the following information: NO(g) + O(g) → NO2(g) ΔrG° = ? 2O3(g) → 3O2(g) ΔrG° = +489.6 kJ mol-1 O2(g) → 2O(g) ΔrG° = +463.4 kJ mol-1 NO(g) + O3(g) → NO2(g) + O2(g) ΔrG° = - 199.5 kJ mol-1

Correct AnswerverifiedShow Answer

Which of the following processes have a ΔrS > 0?

Correct AnswerverifiedShow Answer

Consider a reaction that has a positive ΔrH and a negative ΔrS. Which of the following statements is TRUE?

Correct AnswerverifiedShow Answer

Which of the following relationships is correct at constant T and P?

Correct AnswerverifiedShow Answer

Define the second law of thermodynamics.

Correct AnswerverifiedFor any spontaneous ...View AnswerShow Answer

Consider a reaction that has a positive ΔrH and a positive ΔrS. Which of the following statements is TRUE?

Correct AnswerverifiedShow Answer

Choose the statement below that is TRUE.

Correct AnswerverifiedShow Answer

Which of the following is TRUE if ln K is zero?

Correct AnswerverifiedShow Answer

Given the following equation, N2O(g) + NO2(g) → 3NO(g) ΔrG° = -23.0 kJ mol-1 Calculate ΔrG° for the following reaction: 3N2O(g) + 3NO2(g) → 9NO(g)

Correct AnswerverifiedShow Answer

Correct Answer
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Calculate Δ_rG at 298 K under the conditions shown below for the following reaction: Fe₂O₃(s) + 3CO(g) → 2Fe(s) + 3CO₂(g) ΔG° = -28.0 kJ mol^-1 P(CO) = 1.4 atm, P(CO₂) = 2.1 atm

Correct Answer
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Use Hess's law to calculate Δ_rG° using the following information: NO(g) + O(g) → NO₂(g) Δ_rG°= ? 2O₃(g) → 3O₂(g) Δ_rG°= +489.6 kJ mol^-1 O₂(g) → 2O(g) Δ_rG°= +463.4 kJ mol^-1 NO(g) + O₃(g) → NO₂(g) + O₂(g) Δ_rG°= - 199.5 kJ mol^-1

Correct Answer
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Which of the following processes have a Δ_rS > 0?

Correct Answer
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Consider a reaction that has a positive Δ_rH and a negative Δ_rS. Which of the following statements is TRUE?

Correct Answer
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Correct Answer
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Correct Answer
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For any spontaneous ...
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Consider a reaction that has a positive Δ_rH and a positive Δ_rS. Which of the following statements is TRUE?

Correct Answer
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Correct Answer
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Correct Answer
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Given the following equation, N₂O(g) + NO₂(g) → 3NO(g) Δ_rG° = -23.0 kJ mol^-1 Calculate Δ_rG° for the following reaction: 3N₂O(g) + 3NO₂(g) → 9NO(g)

Correct Answer
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