Question 1

For a given transfer of energy,a greater change in disorder occurs when the temperature is high.

Accepted Answer

A) True 
 B)False

Question 2

When calculating the entropy change as a result of transferring heat reversibly to or from a system,the temperature must be constant.

Accepted Answer

A) True 
 B)False

Question 3

Calculate the entropy of vaporization of water at 25S1U1P1$\circ$S1S1P0C and 1 bar.The molar heat capacities of the liquid and gas are 75 and 34 J·K-1·mol-1,respectively.The molar enthalpy of vaporization of water at its normal boiling point is 40.7 kJ·mol-1.

Accepted Answer

+118 J·K<s

Question 4

For CO2(g)$\rightarrow$ CO2(aq),is the entropy change positive or negative?

Accepted Answer

The answer of For CO2(g)$\rightarrow$ CO2(aq),is the entropy change positive...

Question 5

Sketch a plot of the molar entropy of oxygen gas from 0 K to 200 K.The normal melting and boiling points of oxygen are 55 K and 90 K,respectively.

Accepted Answer

Key points: SS1U1P1$\circ$S1S1P0 = 0 at 0 K; SS1U1P1$\circ$S1S1P0 in

Question 6

For the reaction 2SO3(g)$\rightarrow$ 2SO2(g)+ O2(g)
$\Delta$HrS1U1P1$\circ$S1S1P0= +198 kJ.mol-1 at 298 K.Which statement is true for this reaction?

Accepted Answer

A) The reaction is driven by the enthalpy. 
B) The reaction will not be spontaneous at low temperatures. 
C) ($\Delta$GrS1U1P1$\circ$S1S1P0 will be negative at high temperatures.) 
D) The reaction will not be spontaneous at any temperature. 
E) ($\Delta$GrS1U1P1$\circ$S1S1P0 will be positive at high temperatures.) 
A) The reaction is driven by the enthalpy. 
B) The reaction will not be spontaneous at low temperatures. 
C) ($\Delta$GrS1U1P1$\circ$S1S1P0 will be negative at high temperatures.) 
D) The reaction will not be spontaneous at any temperature. 
E) ($\Delta$GrS1U1P1$\circ$S1S1P0 will be positive at high temperatures.)

Question 7

Calculate the standard entropy of fusion of ethanol at its melting point,159 K.The standard molar enthalpy of fusion of ethanol at its melting point is 5.02 J.K-1.mol-1

Accepted Answer

A) (-5.02 J.K-1.mol-1 ) 
B) (-31.6 J.K-1.mol-1 ) 
C) +5.02 J.K-1.mol-1  
D) +31.6 J.K-1.mol-1  
E) (-44.0 J.K-1.mol-1 ) 
A) (-5.02 J.K-1.mol-1 ) 
B) (-31.6 J.K-1.mol-1 ) 
C) +5.02 J.K-1.mol-1  
D) +31.6 J.K-1.mol-1  
E) (-44.0 J.K-1.mol-1 )

Question 8

The energy levels of two particle in a box systems are given below:   Which molecule,N2,or F2,is better represented by (b)?

Accepted Answer

Question 9

Use Trouton's constant to estimate the enthalpy of condensation of diethyl ether,which boils at 309 K.

Accepted Answer

A) (-26  kJ.mol-1 ) 
B) +26  kJ.mol-1  
C) (-275  kJ.mol-1 ) 
D) (-85  kJ.mol-1 ) 
E) +85  kJ.mol-1  
A) (-26  kJ.mol-1 ) 
B) +26  kJ.mol-1  
C) (-275  kJ.mol-1 ) 
D) (-85  kJ.mol-1 ) 
E) +85  kJ.mol-1

Question 10

Calculate $\Delta$Ssurr° at 298 K for the reaction H2(g)+ F2(g)$\rightarrow$ 2HF(g)
$\Delta$Hr° = -546 kJ.mol-1,$\Delta$Sr° = +14.1 J.K-1.mol-1

Accepted Answer

A) +14.1 J.K-1.mol-1  
B) +1820 J.K-1.mol-1  
C) +1830 J.K-1.mol-1  
D) (-1830 J.K-1.mol-1 ) 
E) (-14.1 J.K-1.mol-1 ) 
A) +14.1 J.K-1.mol-1  
B) +1820 J.K-1.mol-1  
C) +1830 J.K-1.mol-1  
D) (-1830 J.K-1.mol-1 ) 
E) (-14.1 J.K-1.mol-1 )

Question 11

Which of the following would probably have a positive $\Delta$S value?

Accepted Answer

A) He(g,2 atm)$\rightarrow$ He(g,10 atm) 
B) H2(g)+ I2(s)$\rightarrow$ 2HI(g) 
C) 2Ag(s)+ Br2(l)$\rightarrow$ 2AgBr(s) 
D) O2(g)$\rightarrow$ O2(aq) 
E) 2NO2(g)$\rightarrow$N2O4(g) 
A) He(g,2 atm)$\rightarrow$ He(g,10 atm) 
B) H2(g)+ I2(s)$\rightarrow$ 2HI(g) 
C) 2Ag(s)+ Br2(l)$\rightarrow$ 2AgBr(s) 
D) O2(g)$\rightarrow$ O2(aq) 
E) 2NO2(g)$\rightarrow$N2O4(g)

Question 12

For the reaction   is the entropy change positive or negative?

Accepted Answer

The answer of For the reaction   is the...

Question 13

The molar entropy of silver at 298 K is equal to the area under the curve obtained by plotting (from T = 0 to T = 298 K)

Accepted Answer

A) CP versus T. 
B) lnCP versus T. 
C) ln(CP/T)versus T. 
D) CP/T versus T. 
E) CP versus 1/T. 
A) CP versus T. 
B) lnCP versus T. 
C) ln(CP/T)versus T. 
D) CP/T versus T. 
E) CP versus 1/T.

Question 14

The reaction N2(g)+ 3H2(g)$\rightarrow$ 2NH3(g)is exothermic.This reaction will be spontaneous at all temperatures.

Accepted Answer

A) True 
 B)False

Question 15

Predict the sign of the molar Gibbs free energy for the process H2O(s)→ H2O(l)at 1 atm and 1oC,0oC,and -1oC,respectively.

Accepted Answer

A) +,0,and - 
B) (-,0,and +) 
C) (+,+,and -) 
D) (-,-,and +) 
E) +,0,and + 
A) +,0,and - 
B) (-,0,and +) 
C) (+,+,and -) 
D) (-,-,and +) 
E) +,0,and +

Question 16

When barium hydroxide is dissolved in water,the temperature of the solution increases.Which of the following statements regarding this reaction is true?

Accepted Answer

A) The reaction is spontaneous at all temperatures. 
B) The reaction is driven only by the entropy. 
C) The reaction is driven only by the enthalpy. 
D) The reaction is spontaneous only at low temperatures. 
E) The reaction is spontaneous only at high temperatures. 
A) The reaction is spontaneous at all temperatures. 
B) The reaction is driven only by the entropy. 
C) The reaction is driven only by the enthalpy. 
D) The reaction is spontaneous only at low temperatures. 
E) The reaction is spontaneous only at high temperatures.

Question 17

The energy levels of two particle in a box systems are   Which system has the higher entropy?

Accepted Answer

The answer of The energy levels of two particle in...

Question 18

Iodine sublimes at room temperature.The reaction free energy,enthalpy,and entropy for this reaction,respectively,are

Accepted Answer

A) negative,positive,and positive 
B) zero,positive,and positive 
C) zero,positive,and negative 
D) negative,negative,and positive 
E) negative,positive,and negative 
A) negative,positive,and positive 
B) zero,positive,and positive 
C) zero,positive,and negative 
D) negative,negative,and positive 
E) negative,positive,and negative

Question 19

Which of the following has the smallest molar entropy at 298 K?

Accepted Answer

A) Cl2(g) 
B) N2(g) 
C) He(g) 
D) F2(g) 
E) Ne(g) 
A) Cl2(g) 
B) N2(g) 
C) He(g) 
D) F2(g) 
E) Ne(g)

Question 20

Water slowly evaporates at 25oC.Which of the following statements regarding this reaction is true?

Accepted Answer

A) This is a spontaneous reaction that is entropy driven. 
B) This is a spontaneous reaction that is enthalpy driven. 
C) The signs of the reaction enthalpy and entropy,respectively,are + and +. 
D) The signs of the reaction enthalpy and entropy,respectively,are - and -. 
E) This reaction is spontaneous only at 100oC. 
A) This is a spontaneous reaction that is entropy driven. 
B) This is a spontaneous reaction that is enthalpy driven. 
C) The signs of the reaction enthalpy and entropy,respectively,are + and +. 
D) The signs of the reaction enthalpy and entropy,respectively,are - and -. 
E) This reaction is spontaneous only at 100oC.

For a given transfer of energy,a greater change in disorder occurs when the temperature is high.

When calculating the entropy change as a result of transferring heat reversibly to or from a system,the temperature must be constant.

Calculate the entropy of vaporization of water at 25^$\circ$C and 1 bar.The molar heat capacities of the liquid and gas are 75 and 34 J·K^-1·mol^-1,respectively.The molar enthalpy of vaporization of water at its normal boiling point is 40.7 kJ·mol^-1.

For CO₂(g) $\rightarrow$ CO₂(aq),is the entropy change positive or negative?

Sketch a plot of the molar entropy of oxygen gas from 0 K to 200 K.The normal melting and boiling points of oxygen are 55 K and 90 K,respectively.

For the reaction 2SO₃(g) $\rightarrow$ 2SO₂(g)+ O₂(g) $\Delta$ H_r^$\circ$= +198 kJ.mol^-1 at 298 K.Which statement is true for this reaction?

Calculate the standard entropy of fusion of ethanol at its melting point,159 K.The standard molar enthalpy of fusion of ethanol at its melting point is 5.02 J.K^-1.mol^-1

The energy levels of two particle in a box systems are given below: Which molecule,N₂,or F₂,is better represented by (b)?

Use Trouton's constant to estimate the enthalpy of condensation of diethyl ether,which boils at 309 K.

Calculate $\Delta$ S_surr° at 298 K for the reaction H₂(g)+ F₂(g) $\rightarrow$ 2HF(g) $\Delta$ H_r° = -546 kJ.mol^-1, $\Delta$ S_r° = +14.1 J.K^-1.mol^-1

Which of the following would probably have a positive $\Delta$ S value?

For the reaction is the entropy change positive or negative?

The molar entropy of silver at 298 K is equal to the area under the curve obtained by plotting (from T = 0 to T = 298 K)

The reaction N₂(g)+ 3H₂(g) $\rightarrow$ 2NH₃(g)is exothermic.This reaction will be spontaneous at all temperatures.

Predict the sign of the molar Gibbs free energy for the process H₂O(s)→ H₂O(l)at 1 atm and 1^oC,0^oC,and -1^oC,respectively.

When barium hydroxide is dissolved in water,the temperature of the solution increases.Which of the following statements regarding this reaction is true?

The energy levels of two particle in a box systems are Which system has the higher entropy?

Iodine sublimes at room temperature.The reaction free energy,enthalpy,and entropy for this reaction,respectively,are

Which of the following has the smallest molar entropy at 298 K?

Water slowly evaporates at 25^oC.Which of the following statements regarding this reaction is true?

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Exam 9: Thermodynamics: The Second and Third Laws

For a given transfer of energy,a greater change in disorder occurs when the temperature is high.

When calculating the entropy change as a result of transferring heat reversibly to or from a system,the temperature must be constant.

Calculate the entropy of vaporization of water at 25 ∘\circ∘ C and 1 bar.The molar heat capacities of the liquid and gas are 75 and 34 J·K-1·mol-1,respectively.The molar enthalpy of vaporization of water at its normal boiling point is 40.7 kJ·mol-1.

For CO2(g) →\rightarrow→ CO2(aq),is the entropy change positive or negative?

Sketch a plot of the molar entropy of oxygen gas from 0 K to 200 K.The normal melting and boiling points of oxygen are 55 K and 90 K,respectively.

For the reaction 2SO3(g) →\rightarrow→ 2SO2(g)+ O2(g) Δ\DeltaΔ Hr ∘\circ∘ = +198 kJ.mol-1 at 298 K.Which statement is true for this reaction?

Calculate the standard entropy of fusion of ethanol at its melting point,159 K.The standard molar enthalpy of fusion of ethanol at its melting point is 5.02 J.K-1.mol-1

The energy levels of two particle in a box systems are given below: Which molecule,N2,or F2,is better represented by (b)?

Use Trouton's constant to estimate the enthalpy of condensation of diethyl ether,which boils at 309 K.

Calculate Δ\DeltaΔ Ssurr° at 298 K for the reaction H2(g)+ F2(g) →\rightarrow→ 2HF(g) Δ\DeltaΔ Hr° = -546 kJ.mol-1, Δ\DeltaΔ Sr° = +14.1 J.K-1.mol-1

Which of the following would probably have a positive Δ\DeltaΔ S value?

For the reaction is the entropy change positive or negative?

The molar entropy of silver at 298 K is equal to the area under the curve obtained by plotting (from T = 0 to T = 298 K)

The reaction N2(g)+ 3H2(g) →\rightarrow→ 2NH3(g)is exothermic.This reaction will be spontaneous at all temperatures.

Predict the sign of the molar Gibbs free energy for the process H2O(s)→ H2O(l)at 1 atm and 1oC,0oC,and -1oC,respectively.

When barium hydroxide is dissolved in water,the temperature of the solution increases.Which of the following statements regarding this reaction is true?

The energy levels of two particle in a box systems are Which system has the higher entropy?

Iodine sublimes at room temperature.The reaction free energy,enthalpy,and entropy for this reaction,respectively,are

Which of the following has the smallest molar entropy at 298 K?

Water slowly evaporates at 25oC.Which of the following statements regarding this reaction is true?

The Quantum World

Quantum Mechanics in Action: Atoms

Chemical Bonds

Molecular Shape and Structure

The Properties of Gases

Liquids and Solids

Inorganic Materials

Thermodynamics: The First Law

Physical Equilibria

Chemical Equilibria

Acids and Bases

Aqueous Equilibria

Electrochemistry

Chemical Kinetics

The Elements: the Main Group Elements

The Elements: The D Block

Nuclear Chemistry

Organic Chemistry I

Organic Chemistry II

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Calculate the entropy of vaporization of water at 25^$\circ$C and 1 bar.The molar heat capacities of the liquid and gas are 75 and 34 J·K^-1·mol^-1,respectively.The molar enthalpy of vaporization of water at its normal boiling point is 40.7 kJ·mol^-1.

For CO₂(g) $\rightarrow$ CO₂(aq),is the entropy change positive or negative?

For the reaction 2SO₃(g) $\rightarrow$ 2SO₂(g)+ O₂(g) $\Delta$ H_r^$\circ$= +198 kJ.mol^-1 at 298 K.Which statement is true for this reaction?

Calculate the standard entropy of fusion of ethanol at its melting point,159 K.The standard molar enthalpy of fusion of ethanol at its melting point is 5.02 J.K^-1.mol^-1

The energy levels of two particle in a box systems are given below: Which molecule,N₂,or F₂,is better represented by (b)?

Calculate $\Delta$ S_surr° at 298 K for the reaction H₂(g)+ F₂(g) $\rightarrow$ 2HF(g) $\Delta$ H_r° = -546 kJ.mol^-1, $\Delta$ S_r° = +14.1 J.K^-1.mol^-1

Which of the following would probably have a positive $\Delta$ S value?

The reaction N₂(g)+ 3H₂(g) $\rightarrow$ 2NH₃(g)is exothermic.This reaction will be spontaneous at all temperatures.

Predict the sign of the molar Gibbs free energy for the process H₂O(s)→ H₂O(l)at 1 atm and 1^oC,0^oC,and -1^oC,respectively.

Water slowly evaporates at 25^oC.Which of the following statements regarding this reaction is true?