Question 1

Which of these species has the highest entropy (S°)  at 25°C?

Accepted Answer

A)   CH3OH(l) 
B)   CO(g) 
C)   MgCO3(s) 
D)   H2O(l) 
E)   Si(s) F) A) and B)
G) D) and E)

Question 2

For a chemical reaction to be spontaneous at all temperatures, which conditions must be met?

Accepted Answer

A)   ΔS°rxn > 0, ΔH°rxn > 0
B)   ΔS°rxn > 0, ΔH°rxn 
C)   ΔS°rxnrxn 
D)   ΔS°rxn rxn > 0
E)   ΔS°rxn = 0, ΔH°rxn = 0F) All of the above
G) B) and C)

Question 3

What is ΔS° for the following reaction? 2Cl2(g)  + SO2(g)  → SOCl2(g)  + Cl2O(g)  2(g)  + SO2(g)  → SOCl2(g)  + Cl2O(g)    A)  -118.2 J/K • mol B)  -104.8 J/K • mol C)  104.8 J/K • mol D)  118.2 J/K • mol E)  1270.0 J/K • mol" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   -118.2 J/K • mol
B)   -104.8 J/K • mol
C)   104.8 J/K • mol
D)   118.2 J/K • mol
E)   1270.0 J/K • molF) B) and C)
G) C) and D)

Question 4

What is ΔS° for the combustion of propane? C3H8(g)  + 5O2(g)  → 3CO2(g)  + 4H2O(g)  3H8(g)  + 5O2(g)  → 3CO2(g)  + 4H2O(g)    A)  -100.7 J/K B)  -72.6 J/K C)  72.6 J/K D)  100.7 J/K E)  877.2 J/K" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   -100.7 J/K
B)   -72.6 J/K
C)   72.6 J/K
D)   100.7 J/K
E)   877.2 J/KF) B) and E)
G) A) and B)

Question 5

The most probable state is the one with the ________.

Accepted Answer

A)   highest energy
B)   largest number of possible arrangements
C)   lowest number of possible arrangements
D)   most symmetry
E)   highest enthalpyF) All of the above
G) A) and B)

Question 6

What is the third law of thermodynamics?

Accepted Answer

At 0 K all perfectly...

Question 7

For the process C6H6(l)   C6H6(s)  at a temperature above the freezing point of C6H6,

Accepted Answer

A)   ΔS is positive.
B)   ΔH is positive.
C)   ΔG is positive.
D)   ΔG = O.E) A) and B)
F) A) and C)

Question 8

As the molar mass of a compound increases, the entropy ________.

Accepted Answer

A)   decreases
B)   is constant
C)   increasesD) A) and B)
E) B) and C)

Question 9

Predict the sign of ΔS for the reaction 6CO2(g) + 6H2O(g) → C6H12O6(s) + 6O2(g).

Accepted Answer

Question 10

For a process that is spontaneous at high temperatures but not at low temperatures, the sign of ΔH is ________.

Accepted Answer

The answer of For a process that is spontaneous at...

Question 11

At temperatures below 273 K, it is observed that liquid water spontaneously freezes to form solid ice. What must be true about the entropy changes of the system and surroundings for this process?

Accepted Answer

A)   ΔSsys > 0, ΔSsurr > 0
B)   ΔSsys surr > 0
C)   ΔSsys surr 
D)   ΔSsys > 0, ΔSsurr 
E)   ΔSsys = 0, ΔSsurr > 0F) B) and D)
G) A) and D)

Question 12

What term is given to the fact that the entropy of a perfect crystalline solid is zero at absolute zero?

Accepted Answer

A)   1st law of thermodynamics
B)   2nd law of thermodynamics
C)   3rd law of thermodynamics
D)   crystalline lattice theory
E)   absolute crystallinityF) A) and E)
G) A) and D)

Question 13

What is ΔG°rxn for the following reaction? 3NO2(g)  + H2O(l)  → 2HNO3(l)  + NO(g)  rxn for the following reaction? 3NO2(g)  + H2O(l)  → 2HNO3(l)  + NO(g)    A)  +8.7 kJ/mol B)  +192.2 kJ/mol C)  -178.6 kJ/mol D)  -192.2 kJ/mol E)  +639.1 kJ/mol" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   +8.7 kJ/mol
B)   +192.2 kJ/mol
C)   -178.6 kJ/mol
D)   -192.2 kJ/mol
E)   +639.1 kJ/molF) A) and E)
G) C) and E)

Question 14

How many types of vibrations does a bent triatomic molecule exhibit?

Accepted Answer

A)   0
B)   1
C)   2
D)   3
E)   4F) C) and D)
G) B) and D)

Question 15

In 1774 Joseph Priestly prepared oxygen by heating mercury(II)  oxide according to the reaction HgO(l)   Hg(l)  + ½O2(g) , for which ΔHo = 90.84 kJ/mol and ΔSo = 108 J/K.mol. Which of the following statements is true for this reaction?

Accepted Answer

A)   The reaction is spontaneous only at low temperatures.
B)   The reaction is spontaneous at all temperatures.
C)   ΔGo becomes less favorable as temperature increases.
D)   The reaction is spontaneous only at high temperatures.
E)   The reaction is at equilibrium at 25oC and 1 atm pressure.F) A) and C)
G) A) and B)

Question 16

What is ΔS° for the following reaction? 4Cr(s)  + 3O2(g)  → 2Cr2O3(s)  2(g)  → 2Cr2O3(s)    A)  -549.19 J/K • mol B)  -148.26 J/K • mol C)  +148.26 J/K • mol D)  +66.22 J/K • mol E)  +871.80 J/K • mol" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   -549.19 J/K • mol
B)   -148.26 J/K • mol
C)   +148.26 J/K • mol
D)   +66.22 J/K • mol
E)   +871.80 J/K • molF) C) and E)
G) D) and E)

Question 17

State the second and third laws of thermodynamics.

Accepted Answer

All spontaneous processes are ...

Question 18

At constant temperature and pressure, which is the correct relationship between ΔG and other thermodynamic quantities?

Accepted Answer

A)   ΔG = ΔH - TΔS
B)   ΔG = ΔH + TΔS
C)   ΔG = ΔU - TΔS
D)   ΔG = -TΔS
E)   ΔG = q/TF) A) and D)
G) B) and E)

Question 19

The complete combustion of liquid benzene is represented by the equation:
C6H6(l) + 7  O2(g) → 6CO2(g) + 3H2O(l)
Using the data below, calculate, for this reaction
a. ΔH°
b. ΔG° at 25°C.

Accepted Answer

a. -3271 k...

Question 20

For a process where a gas condenses to a liquid, the entropy ________.

Accepted Answer

The answer of For a process where a gas condenses...

Exam 18: Entropy, Free Energy, and Equilibrium

Which of these species has the highest entropy (S°) at 25°C?

Correct AnswerverifiedShow Answer

At temperatures below 273 K, it is observed that liquid water spontaneously freezes to form solid ice. What must be true about the entropy changes of the system and surroundings for this process?

Correct AnswerverifiedShow Answer

For a chemical reaction to be spontaneous at all temperatures, which conditions must be met?

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What is ΔS° for the following reaction? 4Cr(s) + 3O2(g) → 2Cr2O3(s)

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What is ΔS° for the following reaction? 2Cl2(g) + SO2(g) → SOCl2(g) + Cl2O(g)

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For the process C6H6(l) <-----> C6H6(s) at a temperature above the freezing point of C6H6,

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What is the third law of thermodynamics?

Correct AnswerverifiedAt 0 K all perfectly...View AnswerShow Answer

For a process where a gas condenses to a liquid, the entropy ________.

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What is ΔS° for the combustion of propane? C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g)

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What is ΔG°rxn for the following reaction? 3NO2(g) + H2O(l) → 2HNO3(l) + NO(g)

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Predict the sign of ΔS for the reaction 6CO2(g) + 6H2O(g) → C6H12O6(s) + 6O2(g).

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What term is given to the fact that the entropy of a perfect crystalline solid is zero at absolute zero?

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State the second and third laws of thermodynamics.

Correct AnswerverifiedAll spontaneous processes are ...View AnswerShow Answer

For a process that is spontaneous at high temperatures but not at low temperatures, the sign of ΔH is ________.

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The most probable state is the one with the ________.

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At constant temperature and pressure, which is the correct relationship between ΔG and other thermodynamic quantities?

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The complete combustion of liquid benzene is represented by the equation: C6H6(l) + 7 O2(g) → 6CO2(g) + 3H2O(l) Using the data below, calculate, for this reaction a. ΔH° b. ΔG° at 25°C.

Correct Answerverifieda. -3271 k...View AnswerShow Answer

As the molar mass of a compound increases, the entropy ________.

Correct AnswerverifiedShow Answer

How many types of vibrations does a bent triatomic molecule exhibit?

Correct AnswerverifiedShow Answer

In 1774 Joseph Priestly prepared oxygen by heating mercury(II) oxide according to the reaction HgO(l) <----> Hg(l) + ½O2(g) , for which ΔHo = 90.84 kJ/mol and ΔSo = 108 J/K.mol. Which of the following statements is true for this reaction?

Correct AnswerverifiedShow Answer

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What is ΔS° for the following reaction? 4Cr(s) + 3O₂(g) → 2Cr₂O₃(s)

Correct Answer
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What is ΔS° for the following reaction? 2Cl₂(g) + SO₂(g) → SOCl₂(g) + Cl₂O(g)

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For the process C₆H₆(l) <-----> C₆H₆(s) at a temperature above the freezing point of C₆H₆,

Correct Answer
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At 0 K all perfectly...
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What is ΔS° for the combustion of propane? C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(g)

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What is ΔG°_rxn for the following reaction? 3NO₂(g) + H₂O(l) → 2HNO₃(l) + NO(g)

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Predict the sign of ΔS for the reaction 6CO₂(g) + 6H₂O(g) → C₆H₁₂O₆(s) + 6O₂(g).

Correct Answer
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Correct Answer
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All spontaneous processes are ...
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Correct Answer
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The complete combustion of liquid benzene is represented by the equation: C₆H₆(l) + 7 O₂(g) → 6CO₂(g) + 3H₂O(l) Using the data below, calculate, for this reaction a. ΔH° b. ΔG° at 25°C.

Correct Answer
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a. -3271 k...
View Answer

Correct Answer
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Correct Answer
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In 1774 Joseph Priestly prepared oxygen by heating mercury(II) oxide according to the reaction HgO(l) <----> Hg(l) + ½O₂(g) , for which ΔH^o = 90.84 kJ/mol and ΔS^o = 108 J/K.mol. Which of the following statements is true for this reaction?

Correct Answer
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