Question 1

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 low 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 low temperatures. 
E)  It is not possible to determine without more information. 
A)  This reaction will be spontaneous only at low 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 low temperatures. 
E)  It is not possible to determine without more information. D

Question 2

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

Question 3

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

Accepted Answer

A)  +753.5 kJ 
B)  +277.0 kJ 
C)  -676.0 kJ 
D)  -1152.5 kJ 
E)  -225.7 kJ 
A)  +753.5 kJ 
B)  +277.0 kJ 
C)  -676.0 kJ 
D)  -1152.5 kJ 
E)  -225.7 kJ C

Question 4

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 5

Calculate ΔS°rxn for the following reaction.The S∘ for each species is shown below the reaction. C2H2(g)+ 2 H2(g)→ C2H6(g)
S°(J/mol∙K)200.9 130.7 229.2

Accepted Answer

A)  +303.3 J/K 
B)  +560.8 J/K 
C)  -102.4 J/K 
D)  -233.1 J/K 
E)  229.2 J/K 
A)  +303.3 J/K 
B)  +560.8 J/K 
C)  -102.4 J/K 
D)  -233.1 J/K 
E)  229.2 J/K

Question 6

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 7

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 ΔGrxn = ΔG°rxn. 
C)  ΔG°rxn = K 
D)  If ΔG°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 ΔGrxn = ΔG°rxn. 
C)  ΔG°rxn = K 
D)  If ΔG°rxn > 0, the reaction is spontaneous in the reverse direction. 
E)  Under equilibrium conditions, ΔGrxn = 0.

Question 8

Given the following equation, H2O(g)+ CO(g)→ H2(g)+ CO2(g)ΔG°rxn = -28.6 kJ
Calculate ΔG°rxn for the following reaction.
5 H2O(g)+ 5 CO(g)→ 5 H2(g)+ 5 CO2(g)

Accepted Answer

A)  - 143.0 kJ 
B)  + 143.0 kJ 
C)  - 5.72 kJ 
D)  + 5.72 kJ 
E)  -28.6 kJ 
A)  - 143.0 kJ 
B)  + 143.0 kJ 
C)  - 5.72 kJ 
D)  + 5.72 kJ 
E)  -28.6 kJ

Question 9

Use Hess's law to calculate ΔG°rxn using the following information. ClO(g)+ O3(g)→ Cl(g)+ 2 O2(g)ΔG°rxn = ?
2 O3(g)→ 3 O2(g)ΔG°rxn = +489.6 kJ
Cl(g)+ O3(g)→ ClO(g)+ O2(g)ΔG°rxn = -34.5 kJ

Accepted Answer

A)  -472.4 kJ 
B)  -210.3 kJ 
C)  +455.1 kJ 
D)  +262.1 kJ 
E)  +524.1 kJ 
A)  -472.4 kJ 
B)  -210.3 kJ 
C)  +455.1 kJ 
D)  +262.1 kJ 
E)  +524.1 kJ

Question 10

Place the following in order of increasing molar entropy at 298 K. CO2 C10H22 CO

Accepted Answer

A)  CO2 10H22 10H22 2 2 10H22 
D)  C10H22 2 
E)  CO2 10H22 
A)  CO2 10H22 10H22 2 2 10H22 
D)  C10H22 2 
E)  CO2 10H22

Question 11

Which of the following statements is TRUE?

Accepted Answer

A)  Entropy is an extensive property. 
B)  Entropy is temperature independent. 
C)  Exothermic processes decrease the entropy of the surroundings. 
D)  ΔSuniverse is always greater than zero for a nonspontaneous process. 
E)  None of the above are true. 
A)  Entropy is an extensive property. 
B)  Entropy is temperature independent. 
C)  Exothermic processes decrease the entropy of the surroundings. 
D)  ΔSuniverse is always greater than zero for a nonspontaneous process. 
E)  None of the above are true.

Question 12

Define allotrope.

Accepted Answer

An allotrope is two

Question 13

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

Accepted Answer

Some of th

Question 14

Use Hess's law to calculate ΔG°rxn using the following information. CO(g)→ C(s)+ 1/2 O2(g)ΔG°rxn = ?
CO2(g)→ C(s)+ O2(g)ΔG°rxn = +394.4 kJ
CO(g)+ 1/2 O2(g)→ CO2(g)ΔG°rxn = -257.2 kJ

Accepted Answer

A)  -60.0 kJ 
B)  +651.6 kJ 
C)  -265.8 kJ 
D)  +137.2 kJ 
E)  +523.0 kJ 
A)  -60.0 kJ 
B)  +651.6 kJ 
C)  -265.8 kJ 
D)  +137.2 kJ 
E)  +523.0 kJ

Question 15

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 16

Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. CaCO3(s)→ CaO(s)+ CO2(g)ΔG° =+131.1 kJ
P(CO2)= 0.033 atm

Accepted Answer

A)  -49.3 kJ 
B)  -8.32 kJ 
C)  +122.6 kJ 
D)  +39.7 kJ 
E)  +43.3 kJ 
A)  -49.3 kJ 
B)  -8.32 kJ 
C)  +122.6 kJ 
D)  +39.7 kJ 
E)  +43.3 kJ

Question 17

Place the following in order of decreasing molar entropy at 298 K. HCl N2H4 He

Accepted Answer

A)  He > N2H4 > HCl 
B)  He > HCl > N2H4 
C)  N2H4 > He > HCl 
D)  N2H4 > HCl > He 
E)  HCl > N2H4 > He 
A)  He > N2H4 > HCl 
B)  He > HCl > N2H4 
C)  N2H4 > He > HCl 
D)  N2H4 > HCl > He 
E)  HCl > N2H4 > He

Question 18

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 19

Determine the equilibrium constant for the following reaction at 298 K. SO3(g)+ H2O(g)→ H2SO4(l)ΔG° = -90.5 kJ

Accepted Answer

A)  1.37 × 10-16 
B)  4.78 × 1011 
C)  9.11 × 10-8 
D)  7.31 × 1015 
E)  0.964 
A)  1.37 × 10-16 
B)  4.78 × 1011 
C)  9.11 × 10-8 
D)  7.31 × 1015 
E)  0.964

Question 20

For the following example,identify the following. H2O(l)→ H2O(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.

Exam 19: Free Energy and Thermodynamics

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

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

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

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

Calculate ΔS°rxn for the following reaction.The S∘ for each species is shown below the reaction. C2H2(g)+ 2 H2(g)→ C2H6(g) S°(J/mol∙K)200.9 130.7 229.2

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

Which of the following is NOT true for ΔGrxn?

Given the following equation, H2O(g)+ CO(g)→ H2(g)+ CO2(g)ΔG°rxn = -28.6 kJ Calculate ΔG°rxn for the following reaction. 5 H2O(g)+ 5 CO(g)→ 5 H2(g)+ 5 CO2(g)

Use Hess's law to calculate ΔG°rxn using the following information. ClO(g)+ O3(g)→ Cl(g)+ 2 O2(g)ΔG°rxn = ? 2 O3(g)→ 3 O2(g)ΔG°rxn = +489.6 kJ Cl(g)+ O3(g)→ ClO(g)+ O2(g)ΔG°rxn = -34.5 kJ

Place the following in order of increasing molar entropy at 298 K. CO2 C10H22 CO

Which of the following statements is TRUE?

Define allotrope.

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

Use Hess's law to calculate ΔG°rxn using the following information. CO(g)→ C(s)+ 1/2 O2(g)ΔG°rxn = ? CO2(g)→ C(s)+ O2(g)ΔG°rxn = +394.4 kJ CO(g)+ 1/2 O2(g)→ CO2(g)ΔG°rxn = -257.2 kJ

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

Calculate ΔGrxn at 298 K under the conditions shown below for the following reaction. CaCO3(s)→ CaO(s)+ CO2(g)ΔG° =+131.1 kJ P(CO2)= 0.033 atm

Place the following in order of decreasing molar entropy at 298 K. HCl N2H4 He

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

Determine the equilibrium constant for the following reaction at 298 K. SO3(g)+ H2O(g)→ H2SO4(l)ΔG° = -90.5 kJ

For the following example,identify the following. H2O(l)→ H2O(s)

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

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

Calculate ΔS°_rxn for the following reaction.The S^∘for each species is shown below the reaction. C₂H₂(g)+ 2 H₂(g)→ C₂H₆(g) S°(J/mol^∙K)200.9 130.7 229.2

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

Which of the following is NOT true for ΔG_rxn?

Given the following equation, H₂O(g)+ CO(g)→ H₂(g)+ CO₂(g)ΔG°_rxn = -28.6 kJ Calculate ΔG°_rxn for the following reaction. 5 H₂O(g)+ 5 CO(g)→ 5 H₂(g)+ 5 CO₂(g)

Use Hess's law to calculate ΔG°_rxn using the following information. ClO(g)+ O₃(g)→ Cl(g)+ 2 O₂(g)ΔG°_rxn= ? 2 O₃(g)→ 3 O₂(g)ΔG°_rxn= +489.6 kJ Cl(g)+ O₃(g)→ ClO(g)+ O₂(g)ΔG°_rxn= -34.5 kJ

Place the following in order of increasing molar entropy at 298 K. CO₂ C₁₀H₂₂ CO

Use Hess's law to calculate ΔG°_rxn using the following information. CO(g)→ C(s)+ 1/2 O₂(g)ΔG°_rxn= ? CO₂(g)→ C(s)+ O₂(g)ΔG°_rxn= +394.4 kJ CO(g)+ 1/2 O₂(g)→ CO₂(g)ΔG°_rxn= -257.2 kJ

Calculate ΔG_rxn at 298 K under the conditions shown below for the following reaction. CaCO₃(s)→ CaO(s)+ CO₂(g)ΔG° =+131.1 kJ P(CO₂)= 0.033 atm

Place the following in order of decreasing molar entropy at 298 K. HCl N₂H₄ He

Determine the equilibrium constant for the following reaction at 298 K. SO₃(g)+ H₂O(g)→ H₂SO₄(l)ΔG° = -90.5 kJ

For the following example,identify the following. H₂O(l)→ H₂O(s)