Question 1

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

Question 2

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

Question 3

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

Question 4

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. 
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

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

Question 6

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

Accepted Answer

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

Question 7

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

Question 8

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. 
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 9

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

Question 10

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

Question 12

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. 
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 13

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) 
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 14

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. 
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 15

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

Question 16

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

Question 17

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

Question 18

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 19

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

Question 20

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. 
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.

Exam 18: Free Energy and Thermodynamics

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

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

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

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

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)

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

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

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

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

Which of the following statements is TRUE?

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

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

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

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

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

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

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

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.

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

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

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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

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)

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

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

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

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

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

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

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

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