Question 1

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 2

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 3

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) B) and E)

Question 4

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) B) and D)
G) A) and C)

Question 5

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 D)
G) C) and D)

Question 6

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

Accepted Answer

Question 7

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

Accepted Answer

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

Question 8

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) A) and E)
G) A) and B)

Question 9

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 B)
G) C) and D)

Question 10

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) B) and C)
G) B) and D)

Question 11

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 12

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

Accepted Answer

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

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) A) and D)

Question 14

What is the third law of thermodynamics?

Accepted Answer

At 0 K all perfectly...

Question 15

State the second and third laws of thermodynamics.

Accepted Answer

All spontaneous processes are ...

Question 16

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) D) and E)
G) B) and C)

Question 17

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) C) and E)
G) A) and B)

Question 18

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) A) and B)
G) A) and C)

Question 19

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) None of the above

Question 20

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

Accepted Answer

A)   decreases
B)   is constant
C)   increasesD) All of the above
E) A) and B)

Exam 18: Entropy, Free Energy, and Equilibrium

The most probable state is the one with the ________.

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

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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 ΔHo = 90.84 kJ/mol and ΔSo = 108 J/K.mol. Which of the following statements is true for this reaction?

Correct AnswerverifiedShow Answer

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

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

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

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

Correct AnswerverifiedShow Answer

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

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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?

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What is the third law of thermodynamics?

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

State the second and third laws of thermodynamics.

Correct AnswerverifiedAll spontaneous processes are ...View AnswerShow Answer

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

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

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? 2Cl2(g) + SO2(g) → SOCl2(g) + Cl2O(g)

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

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

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

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

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

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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?

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

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

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At 0 K all perfectly...
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All spontaneous processes are ...
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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...
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What is ΔS° for the following reaction? 2Cl₂(g) + SO₂(g) → SOCl₂(g) + Cl₂O(g)

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

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

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