Question 1

How is a nonspontaneous process made spontaneous?

Accepted Answer

The nonspontaneous process is coupled wi

Question 2

Estimate ΔG°rxn for the following reaction at 449.0 K. CH2O(g)+ 2 H2(g)→ CH4(g)+ H2O(g)ΔH°= -94.9 kJ; ΔS°= -224.2 J/K

Accepted Answer

A)  +5.8 kJ 
B)  -12.9 kJ 
C)  -101 kJ 
D)  -5.8 kJ 
E)  -4.2 kJ 
A)  +5.8 kJ 
B)  -12.9 kJ 
C)  -101 kJ 
D)  -5.8 kJ 
E)  -4.2 kJ

Question 3

Calculate ΔS°rxn for the following reaction.The S° for each species is shown below the reaction. 4 NH3(g)+ 5 O2(g)→ 4 NO(g)+ 6 H2O(g)
S°(J/mol∙K)192.8 205.2 210.8 188.8

Accepted Answer

A)  -287.4 J/K 
B)  -401.2 J/K 
C)  +160.0 J/K 
D)  +336.6 J/K 
E)  +178.8 J/K 
A)  -287.4 J/K 
B)  -401.2 J/K 
C)  +160.0 J/K 
D)  +336.6 J/K 
E)  +178.8 J/K

Question 4

Define entropy.

Accepted Answer

Entropy is a thermodynamic fun

Question 5

Consider a reaction that has a negative 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 6

A spontaneous reaction occurs

Accepted Answer

A)  with expansion of the volume. 
B)  with the application of cold. 
C)  with the application of heat. 
D)  without ongoing outside intervention. 
E)  with a catalyst. 
A)  with expansion of the volume. 
B)  with the application of cold. 
C)  with the application of heat. 
D)  without ongoing outside intervention. 
E)  with a catalyst.

Question 7

Place the following in order of decreasing molar entropy at 298 K. H2 Cl2 F2

Accepted Answer

A)  H2 > Cl2 > F2 
B)  Cl2 > H2 > F2 
C)  F2 > Cl2 > H2 
D)  H2 > F2 > Cl2 
E)  Cl2 > F2 > H2 
A)  H2 > Cl2 > F2 
B)  Cl2 > H2 > F2 
C)  F2 > Cl2 > H2 
D)  H2 > F2 > Cl2 
E)  Cl2 > F2 > H2

Question 8

Above what temperature does the following reaction become nonspontaneous? 2 H2S(g)+ 3 O2(g)→ 2 SO2(g)+ 2 H2O(g)ΔH = -1036 kJ; ΔS = -153.2 J/K

Accepted Answer

A)  6.762 × 103 K 
B)  158.7 K 
C)  298 K 
D)  This reaction is nonspontaneous at all temperatures. 
E)  This reaction is spontaneous at all temperatures. 
A)  6.762 × 103 K 
B)  158.7 K 
C)  298 K 
D)  This reaction is nonspontaneous at all temperatures. 
E)  This reaction is spontaneous at all temperatures.

Question 9

For the following example,identify the following. 2 F2O(g)→ 2 F2(g)+ O2(g)

Accepted Answer

A)  at low temperature, the reaction is spontaneous and ΔG  0 and at high temperature, the reaction is spontaneous and ΔG  0 
D)  at low temperature, the reaction is nonspontaneous and ΔG > 0 and at high temperature, the reaction is nonspontaneous and ΔG > 0 
E)  It is not possible to determine without more information. 
A)  at low temperature, the reaction is spontaneous and ΔG  0 and at high temperature, the reaction is spontaneous and ΔG  0 
D)  at low temperature, the reaction is nonspontaneous and ΔG > 0 and at high temperature, the reaction is nonspontaneous and ΔG > 0 
E)  It is not possible to determine without more information.

Question 10

Why is the quantity of energy required to recharge a battery greater than the quantity of work done?

Accepted Answer

Some of th

Question 11

Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. 2 Hg(g)+ O2(g)→ 2 HgO(s)ΔG° = -180.8 kJ
P(Hg)= 0.025 atm,P(O2)= 0.037 atm

Accepted Answer

A)  +207 kJ 
B)  -154.4 kJ 
C)  -26.5 kJ 
D)  -164 kJ 
E)  +60.7 kJ 
A)  +207 kJ 
B)  -154.4 kJ 
C)  -26.5 kJ 
D)  -164 kJ 
E)  +60.7 kJ

Question 12

Given the following equation, N2O(g)+ NO2(g)→ 3 NO(g)ΔG°rxn = -23.0 kJ
Calculate ΔG°rxn for the following reaction.
6 N2O(g)+ 6 NO2(g)→ 18 NO(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 13

An endothermic reaction is a process that

Accepted Answer

A)  has a negative ΔHsys and a positive ΔSsurr. 
B)  has a negative ΔHsys and a negative ΔSsurr. 
C)  has a positive ΔHsys and a positive ΔSsurr. 
D)  has a positive ΔHsys and a negative ΔSsurr. 
A)  has a negative ΔHsys and a positive ΔSsurr. 
B)  has a negative ΔHsys and a negative ΔSsurr. 
C)  has a positive ΔHsys and a positive ΔSsurr. 
D)  has a positive ΔHsys and a negative ΔSsurr.

Question 14

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

Accepted Answer

A)  at low temperature, the reaction is spontaneous and ΔG  0 and at high temperature, the reaction is spontaneous and ΔG  0 
D)  at low temperature, the reaction is nonspontaneous and ΔG > 0 and at high temperature, the reaction is nonspontaneous and ΔG > 0 
E)  It is not possible to determine without more information. 
A)  at low temperature, the reaction is spontaneous and ΔG  0 and at high temperature, the reaction is spontaneous and ΔG  0 
D)  at low temperature, the reaction is nonspontaneous and ΔG > 0 and at high temperature, the reaction is nonspontaneous and ΔG > 0 
E)  It is not possible to determine without more information.

Question 15

Which of the following is NOT true for ΔGrxn?

Accepted Answer

A)  If ΔG°rxn > 0, the reaction is spontaneous in the forward direction. 
B)  If Q = 1, then DGrxn = ΔG°rxn. 
C)  If ΔG°rxn rxn > 0, the reaction is spontaneous in the reverse direction. 
E)  Under equilibrium conditions, ΔGrxn = 0. 
A)  If ΔG°rxn > 0, the reaction is spontaneous in the forward direction. 
B)  If Q = 1, then DGrxn = ΔG°rxn. 
C)  If ΔG°rxn rxn > 0, the reaction is spontaneous in the reverse direction. 
E)  Under equilibrium conditions, ΔGrxn = 0.

Question 16

Calculate ΔS°rxn for the following reaction.The S° for each species is shown below the reaction. N2H4(l)+ H2(g)→ 2 NH3(g)
S° (J/mol∙K)121.2 130.7 192.8

Accepted Answer

A)  +133.7 J/K 
B)  -59.1 J/K 
C)  +118.2 J/K 
D)  +202.3 J/K 
E)  -444.7 J/K 
A)  +133.7 J/K 
B)  -59.1 J/K 
C)  +118.2 J/K 
D)  +202.3 J/K 
E)  -444.7 J/K

Question 17

For a given compound,list the decreasing order of entropy for a liquid,solid,and gas.

Accepted Answer

A)  solid > gas > liquid 
B)  liquid > solid > gas 
C)  gas > liquid > solid 
D)  gas > solid > liquid 
E)  solid > liquid > gas 
A)  solid > gas > liquid 
B)  liquid > solid > gas 
C)  gas > liquid > solid 
D)  gas > solid > liquid 
E)  solid > liquid > gas

Question 18

What is true if ln K is 1?

Accepted Answer

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

Question 19

Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. 3 O2(g)→ 2 O3(g)ΔG° = +326 kJ
P(O2)= 0.41 atm,P(O3)= 5.2 atm

Accepted Answer

A)  +341 kJ 
B)  +17.8 kJ 
C)  +332 kJ 
D)  -47.4 kJ 
E)  -109 kJ 
A)  +341 kJ 
B)  +17.8 kJ 
C)  +332 kJ 
D)  -47.4 kJ 
E)  -109 kJ

Question 20

Define allotrope.

Accepted Answer

Allotropes are diffe

Exam 18: Free Energy and Thermodynamics

How is a nonspontaneous process made spontaneous?

Estimate ΔG°rxn for the following reaction at 449.0 K. CH2O(g)+ 2 H2(g)→ CH4(g)+ H2O(g)ΔH°= -94.9 kJ; ΔS°= -224.2 J/K

Calculate ΔS°rxn for the following reaction.The S° for each species is shown below the reaction. 4 NH3(g)+ 5 O2(g)→ 4 NO(g)+ 6 H2O(g) S°(J/mol∙K)192.8 205.2 210.8 188.8

Define entropy.

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

A spontaneous reaction occurs

Place the following in order of decreasing molar entropy at 298 K. H2 Cl2 F2

Above what temperature does the following reaction become nonspontaneous? 2 H2S(g)+ 3 O2(g)→ 2 SO2(g)+ 2 H2O(g)ΔH = -1036 kJ; ΔS = -153.2 J/K

For the following example,identify the following. 2 F2O(g)→ 2 F2(g)+ O2(g)

Why is the quantity of energy required to recharge a battery greater than the quantity of work done?

Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. 2 Hg(g)+ O2(g)→ 2 HgO(s)ΔG° = -180.8 kJ P(Hg)= 0.025 atm,P(O2)= 0.037 atm

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

An endothermic reaction is a process that

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

Which of the following is NOT true for ΔGrxn?

Calculate ΔS°rxn for the following reaction.The S° for each species is shown below the reaction. N2H4(l)+ H2(g)→ 2 NH3(g) S° (J/mol∙K)121.2 130.7 192.8

For a given compound,list the decreasing order of entropy for a liquid,solid,and gas.

What is true if ln K is 1?

Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. 3 O2(g)→ 2 O3(g)ΔG° = +326 kJ P(O2)= 0.41 atm,P(O3)= 5.2 atm

Define allotrope.

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Estimate ΔG°_rxn for the following reaction at 449.0 K. CH₂O(g)+ 2 H₂(g)→ CH₄(g)+ H₂O(g)ΔH°= -94.9 kJ; ΔS°= -224.2 J/K

Calculate ΔS°_rxn for the following reaction.The S° for each species is shown below the reaction. 4 NH₃(g)+ 5 O₂(g)→ 4 NO(g)+ 6 H₂O(g) S°(J/mol∙K)192.8 205.2 210.8 188.8

Place the following in order of decreasing molar entropy at 298 K. H₂ Cl₂ F₂

Above what temperature does the following reaction become nonspontaneous? 2 H₂S(g)+ 3 O₂(g)→ 2 SO₂(g)+ 2 H₂O(g)ΔH = -1036 kJ; ΔS = -153.2 J/K

For the following example,identify the following. 2 F₂O(g)→ 2 F₂(g)+ O₂(g)

Calculate ΔG_rxn at 298 K under the conditions shown below for the following reaction. 2 Hg(g)+ O₂(g)→ 2 HgO(s)ΔG° = -180.8 kJ P(Hg)= 0.025 atm,P(O₂)= 0.037 atm

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

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

Which of the following is NOT true for ΔG_rxn?

Calculate ΔS°_rxn for the following reaction.The S° for each species is shown below the reaction. N₂H₄(l)+ H₂(g)→ 2 NH₃(g) S° (J/mol∙K)121.2 130.7 192.8

Calculate ΔG_rxn at 298 K under the conditions shown below for the following reaction. 3 O₂(g)→ 2 O₃(g)ΔG° = +326 kJ P(O₂)= 0.41 atm,P(O₃)= 5.2 atm