Question 1

Place the following in order of increasing entropy at 298 K. Ne Xe He Ar Kr

Accepted Answer

A)   He 
B)   Xe 
C)   Ar 
D)   Ar 
E)   He < Ne < Ar < Kr < Xe

Question 2

Given the following equation, N2O(g) + NO2(g) → 3 NO(g) ΔG°rxn = -23.0 kJ
Calculate ΔG°rxn for the following reaction.
18 NO(g) → 6 N2O(g) + 6 NO2(g)

Accepted Answer

A)   -23.0 kJ
B)   138 kJ
C)   -138 kJ
D)   -3.83 kJ
E)   23.0 kJ

Question 3

Place the following in order of decreasing standard molar entropy. NaI(s) K3PO4(aq) NaI(aq)

Accepted Answer

A)   NaI(s)  > NaI(aq)  > K3PO4(aq) 
B)   NaI(aq)  > NaI(s)  > K3PO4(aq) 
C)   K3PO4(aq)  > NaI(aq)  > NaI(s) 
D)   NaI(s)  > K3PO4(aq)  > NaI(aq) 
E)   NaI(aq)  > K3PO4(aq)  > NaI(s)

Question 4

Consider a reaction that has a negative ΔH and a positive ΔS.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)   It is not possible to determine without more information.

Question 5

Calculate the ΔG°rxn using the following information. 2 H2S(g) + 3 O2(g) → 2 SO2(g) + 2 H2O(g) ΔG°rxn = ?
ΔH°f (kJ/mol) -20.6 -296.8 -241.8
S°(J/mol∙K) 205.8 205.2 248.2 188.8

Accepted Answer

A)   -990.3 kJ
B)   +108.2 kJ
C)   -466.1 kJ
D)   +676.2 kJ
E)   -147.1 kJ

Question 6

Consider a reaction that has a positive ΔH and a negative ΔS.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)   It is not possible to determine without more information.

Question 7

Below what temperature does the following reaction become nonspontaneous? 2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l) ΔH = +136.5 kJ; ΔS = +287.5 J/K

Accepted Answer

A)   39.2 K
B)   151 K
C)   475 K
D)   This reaction is nonspontaneous at all temperatures.
E)   This reaction is spontaneous at all temperatures.

Question 8

Give the name of the reaction that achieves the theoretical limits with respect to free energy in thermodynamics.

Accepted Answer

A)   reversible reaction
B)   forward reaction
C)   reverse reaction
D)   equilibrium reaction
E)   irreversible reaction

Question 9

Identify the change in state that does NOT have an increase in entropy.

Accepted Answer

A)   water freezing
B)   water boiling
C)   ice melting
D)   dry ice subliming
E)   water evaporating A

Question 10

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

Accepted Answer

A)   +31.0 kJ
B)   -31.0 kJ
C)   -28.0 kJ
D)   +25.0 kJ
E)   -25.0 kJ

Question 11

Calculate the ΔG°rxn using the following information. 2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l) ΔG°rxn = ?
ΔG°f (kJ/mol) -110.9 87.6 51.3 -237.1

Accepted Answer

A)   -162.5 kJ
B)   +51.0 kJ
C)   -54.5 kJ
D)   -171.1 kJ
E)   -51.0 kJ

Question 12

For the following example,identify the following. F2(l) → F2(s)

Accepted Answer

A)   a negative ΔH and a negative ΔS
B)   a positive ΔH and a negative ΔS
C)   a negative ΔH and a positive ΔS
D)   a positive ΔH and a positive ΔS
E)   It is not possible to determine without more information.

Question 13

Determine the equilibrium constant for the following reaction at 549 K. CH2O(g) + 2 H2(g) → CH4(g) + H2O(g) ΔH° = -94.9 kJ; ΔS°= -224.2 J/K

Accepted Answer

A)   481
B)   1.07 × 109
C)   2.08 × 10-3
D)   9.35 × 10-10
E)   1.94 × 10-12 C

Question 14

Determine the equilibrium constant for the following reaction at 655 K. HCN(g) + 2 H2(g) → CH3NH2(g) ΔH° = -158 kJ; ΔS°= -219.9 J/K

Accepted Answer

A)   3.99 × 1012
B)   13.0
C)   2.51 × 10-13
D)   3.26 × 10-12
E)   3.07 × 1011

Question 15

How many microstates are possible in a collection of four particles that are present,with two particles each in two connected flasks? Sketch them below.

Accepted Answer

There are six micros...

Question 16

Which of the following statements is TRUE?

Accepted Answer

A)   There is a "heat tax" for every energy transaction.
B)   A spontaneous reaction is always a fast reaction.
C)   The entropy of a system always decreases for a spontaneous process.
D)   Perpetual motion machines are a possibility in the near future.
E)   None of the above is true.

Question 17

What can change the direction of a reversible reaction involving gases?

Accepted Answer

A)   change in temperature
B)   change in pressure
C)   change in volume
D)   all of the above
E)   none of the above

Question 18

What is the sign of Δuniv for a living biological system?

Accepted Answer

A)   positive
B)   negative
C)   zero
D)   It depends on the biological system. A

Question 19

Consider a reaction that has a positive ΔH and a positive ΔS.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)   It is not possible to determine without more information.

Question 20

Place the following in order of increasing molar entropy at 298 K. CO  C5H12 H2

Accepted Answer

A)   CO  5H12 2
B)   C5H12  2
C)   H2  5H12
D)   C5H12 2  
E)   CO 2 5H12

Exam 18: Free Energy and Thermodynamics

Place the following in order of increasing entropy at 298 K. Ne Xe He Ar Kr

Correct AnswerverifiedShow Answer

Given the following equation, N2O(g) + NO2(g) → 3 NO(g) ΔG°rxn = -23.0 kJ Calculate ΔG°rxn for the following reaction. 18 NO(g) → 6 N2O(g) + 6 NO2(g)

Correct AnswerverifiedShow Answer

Place the following in order of decreasing standard molar entropy. NaI(s) K3PO4(aq) NaI(aq)

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Calculate the ΔG°rxn using the following information. 2 H2S(g) + 3 O2(g) → 2 SO2(g) + 2 H2O(g) ΔG°rxn = ? ΔH°f (kJ/mol) -20.6 -296.8 -241.8 S°(J/mol∙K) 205.8 205.2 248.2 188.8

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Below what temperature does the following reaction become nonspontaneous? 2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l) ΔH = +136.5 kJ; ΔS = +287.5 J/K

Correct AnswerverifiedShow Answer

Give the name of the reaction that achieves the theoretical limits with respect to free energy in thermodynamics.

Correct AnswerverifiedShow Answer

Identify the change in state that does NOT have an increase in entropy.

Correct AnswerverifiedA

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

Correct AnswerverifiedShow Answer

Calculate the ΔG°rxn using the following information. 2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l) ΔG°rxn = ? ΔG°f (kJ/mol) -110.9 87.6 51.3 -237.1

Correct AnswerverifiedShow Answer

For the following example,identify the following. F2(l) → F2(s)

Correct AnswerverifiedShow Answer

Determine the equilibrium constant for the following reaction at 549 K. CH2O(g) + 2 H2(g) → CH4(g) + H2O(g) ΔH° = -94.9 kJ; ΔS°= -224.2 J/K

Correct AnswerverifiedC

Determine the equilibrium constant for the following reaction at 655 K. HCN(g) + 2 H2(g) → CH3NH2(g) ΔH° = -158 kJ; ΔS°= -219.9 J/K

Correct AnswerverifiedShow Answer

How many microstates are possible in a collection of four particles that are present,with two particles each in two connected flasks? Sketch them below.

Correct AnswerverifiedThere are six micros...View AnswerShow Answer

Which of the following statements is TRUE?

Correct AnswerverifiedShow Answer

What can change the direction of a reversible reaction involving gases?

Correct AnswerverifiedShow Answer

What is the sign of Δuniv for a living biological system?

Correct AnswerverifiedA

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

Correct AnswerverifiedShow Answer

Place the following in order of increasing molar entropy at 298 K. CO C5H12 H2

Correct AnswerverifiedShow Answer

Correct Answer
verified

Given the following equation, N₂O(g) + NO₂(g) → 3 NO(g) ΔG°_rxn = -23.0 kJ Calculate ΔG°_rxn for the following reaction. 18 NO(g) → 6 N₂O(g) + 6 NO₂(g)

Correct Answer
verified

Place the following in order of decreasing standard molar entropy. NaI(s) K₃PO₄(aq) NaI(aq)

Correct Answer
verified

Correct Answer
verified

Calculate the ΔG°_rxn using the following information. 2 H₂S(g) + 3 O₂(g) → 2 SO₂(g) + 2 H₂O(g) ΔG°_rxn= ? ΔH°_f (kJ/mol) -20.6 -296.8 -241.8 S°(J/mol∙K) 205.8 205.2 248.2 188.8

Correct Answer
verified

Correct Answer
verified

Below what temperature does the following reaction become nonspontaneous? 2 HNO₃(aq) + NO(g) → 3 NO₂(g) + H₂O(l) ΔH = +136.5 kJ; ΔS = +287.5 J/K

Correct Answer
verified

Correct Answer
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Correct Answer
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A

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

Correct Answer
verified

Calculate the ΔG°_rxn using the following information. 2 HNO₃(aq) + NO(g) → 3 NO₂(g) + H₂O(l) ΔG°_rxn= ? ΔG°_f (kJ/mol) -110.9 87.6 51.3 -237.1

Correct Answer
verified

For the following example,identify the following. F₂(l) → F₂(s)

Correct Answer
verified

Determine the equilibrium constant for the following reaction at 549 K. CH₂O(g) + 2 H₂(g) → CH₄(g) + H₂O(g) ΔH° = -94.9 kJ; ΔS°= -224.2 J/K

Correct Answer
verified
C

Determine the equilibrium constant for the following reaction at 655 K. HCN(g) + 2 H₂(g) → CH₃NH₂(g) ΔH° = -158 kJ; ΔS°= -219.9 J/K

Correct Answer
verified

Correct Answer
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There are six micros...
View Answer

Correct Answer
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Correct Answer
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Correct Answer
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A

Correct Answer
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Place the following in order of increasing molar entropy at 298 K. CO C₅H₁₂ H₂

Correct Answer
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