Question 1

Which one of the following would be expected to have the lowest standard molar entropy,S°,at 25°C?

Accepted Answer

A) C H4(g) 
B) C3H6(g) 
C) C3H8(g) 
D) C4 H10OH(g) 
A) C H4(g) 
B) C3H6(g) 
C) C3H8(g) 
D) C4 H10OH(g)

Question 2

At 25°C,ΔG° = -198 kJ for the reaction,NO(g)+ O3(g)⇌ NO2(g)+ O2(g). Calculate ΔG under the following conditions:

Accepted Answer

A) -159 kJ 
B) -167 kJ 
C) -198 kJ 
D) -236 kJ 
A) -159 kJ 
B) -167 kJ 
C) -198 kJ 
D) -236 kJ

Question 3

A reaction has ΔH° = -60.9 kJ/mol and ΔS° = 266.6 J/K.Is this reaction spontaneous or nonspontaneous? At what temperature (if any)can the spontaneity be reversed?

Accepted Answer

A) nonspontaneous,can be made spontaneous at 228 K 
B) nonspontaneous,cannot be made spontaneous at any temperature 
C) spontaneous,can be made nonspontaneous at 228 K 
D) spontaneous,cannot be made nonspontaneous at any temperature 
A) nonspontaneous,can be made spontaneous at 228 K 
B) nonspontaneous,cannot be made spontaneous at any temperature 
C) spontaneous,can be made nonspontaneous at 228 K 
D) spontaneous,cannot be made nonspontaneous at any temperature

Question 4

The most commonly used white pigment is titanium white,which is titanium(IV)oxide,TiO2.Titanium white can be formed from TiCl4 as shown in the reaction below.
TiCl4(l)+ 2 H2O(l)→ TiO2(s)+ 4 HCl(g)
If ΔH° = 61.9 kJ/mol and ΔS° = 405.4 J/K,what are ΔSsurr and ΔStotal for this reaction at 25°C?

Accepted Answer

-207.7 J/K

Question 5

Predict the sign of ΔS of the system for both of the following. I.2 C(graphite)+ O2(g)→ 2 CO(g)
II.C4H10(g)→ C4H10(l)

Accepted Answer

A) ΔS should be negative for I and negative for II. 
B) ΔS should be negative for I and positive for II. 
C) ΔS should be positive for I and negative for II. 
D) ΔS should be positive for I and positive for II. 
A) ΔS should be negative for I and negative for II. 
B) ΔS should be negative for I and positive for II. 
C) ΔS should be positive for I and negative for II. 
D) ΔS should be positive for I and positive for II.

Question 6

What is the entropy change associated with the expansion of one mole of an ideal gas from an initial volume of V to a final volume of V of 2.50V at constant temperature?

Accepted Answer

A) ΔS = 2.50 R ln (Vf/Vi) 
B) ΔS = -2.50 R ln (Vf/Vi) 
C) ΔS = R ln 2.50 
D) ΔS = -R ln 2.50 
A) ΔS = 2.50 R ln (Vf/Vi) 
B) ΔS = -2.50 R ln (Vf/Vi) 
C) ΔS = R ln 2.50 
D) ΔS = -R ln 2.50

Question 7

The figure represents the spontaneous deposition of iodine in which iodine vapor,I2(g),becomes crystalline iodine solid I2(s): I2(g): → I2(s).What are the signs (+ or -)of ΔH,ΔS,and ΔG for this process?

Accepted Answer

A) ΔH = +,ΔS = +,ΔG = + 
B) ΔH = +,ΔS = +,ΔG = - 
C) ΔH = -,ΔS = -,ΔG = + 
D) ΔH = -,ΔS = -,ΔG = - 
A) ΔH = +,ΔS = +,ΔG = + 
B) ΔH = +,ΔS = +,ΔG = - 
C) ΔH = -,ΔS = -,ΔG = + 
D) ΔH = -,ΔS = -,ΔG = -

Question 8

For the reaction N2(g)+ 2 O2(g)→ 2 NO2(g),ΔH° = 66.4 kJ/mol and ΔS° = -121.5 J/K.Is there a temperature at which the spontaneity of this reaction be changed,either from spontaneous to nonspontaneous or nonspontaneous to spontaneous? If so,estimate the temperature.

Accepted Answer

This reaction is non

Question 9

Predict the sign of ΔS for each of the following processes,which occur at constant temperature. I.The volume of 2.0 moles of O2(g)increases from 44 L to 52 L.
II.The pressure of 2.0 moles of O2(g)increases from 1.0 atm to 1.2 atm.

Accepted Answer

A) I: ΔS = negative;II: ΔS = negative 
B) I: ΔS = negative;II: ΔS = positive 
C) I: ΔS = positive;II: ΔS = negative 
D) I: ΔS = positive;II: ΔS = positive 
A) I: ΔS = negative;II: ΔS = negative 
B) I: ΔS = negative;II: ΔS = positive 
C) I: ΔS = positive;II: ΔS = negative 
D) I: ΔS = positive;II: ΔS = positive

Question 10

Which is the lowest at 25°C?

Accepted Answer

A) ΔG°f for H2O (s) 
B) ΔG°f for H2O (l) 
C) ΔG°f for H2O (g) 
D) 1/2ΔG°f for O2 (g)plus ΔG°f for H2O (g) 
A) ΔG°f for H2O (s) 
B) ΔG°f for H2O (l) 
C) ΔG°f for H2O (g) 
D) 1/2ΔG°f for O2 (g)plus ΔG°f for H2O (g)

Which one of the following would be expected to have the lowest standard molar entropy,S°,at 25°C?

At 25°C,ΔG° = -198 kJ for the reaction,NO(g)+ O₃(g)⇌ NO₂(g)+ O₂(g). Calculate ΔG under the following conditions:

A reaction has ΔH° = -60.9 kJ/mol and ΔS° = 266.6 J/K.Is this reaction spontaneous or nonspontaneous? At what temperature (if any)can the spontaneity be reversed?

Predict the sign of ΔS of the system for both of the following. I.2 C(graphite)+ O₂(g)→ 2 CO(g) II.C₄H₁₀(g)→ C₄H₁₀(l)

What is the entropy change associated with the expansion of one mole of an ideal gas from an initial volume of V to a final volume of V of 2.50V at constant temperature?

The figure represents the spontaneous deposition of iodine in which iodine vapor,I₂(g),becomes crystalline iodine solid I₂(s): I₂(g): → I₂(s).What are the signs (+ or -)of ΔH,ΔS,and ΔG for this process?

For the reaction N₂(g)+ 2 O₂(g)→ 2 NO₂(g),ΔH° = 66.4 kJ/mol and ΔS° = -121.5 J/K.Is there a temperature at which the spontaneity of this reaction be changed,either from spontaneous to nonspontaneous or nonspontaneous to spontaneous? If so,estimate the temperature.

Predict the sign of ΔS for each of the following processes,which occur at constant temperature. I.The volume of 2.0 moles of O₂(g)increases from 44 L to 52 L. II.The pressure of 2.0 moles of O₂(g)increases from 1.0 atm to 1.2 atm.

Which is the lowest at 25°C?

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Covalent Compounds: Bonding Theories and Molecular Structure

Thermochemistry: Chemical Energy

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Solutions and Their Properties

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Chemical Equilibrium

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Exam 17: Thermodynamics: Entropy, free Energy, and Equilibrium

Which one of the following would be expected to have the lowest standard molar entropy,S°,at 25°C?

At 25°C,ΔG° = -198 kJ for the reaction,NO(g)+ O3(g)⇌ NO2(g)+ O2(g). Calculate ΔG under the following conditions:

A reaction has ΔH° = -60.9 kJ/mol and ΔS° = 266.6 J/K.Is this reaction spontaneous or nonspontaneous? At what temperature (if any)can the spontaneity be reversed?

Predict the sign of ΔS of the system for both of the following. I.2 C(graphite)+ O2(g)→ 2 CO(g) II.C4H10(g)→ C4H10(l)

What is the entropy change associated with the expansion of one mole of an ideal gas from an initial volume of V to a final volume of V of 2.50V at constant temperature?

The figure represents the spontaneous deposition of iodine in which iodine vapor,I2(g),becomes crystalline iodine solid I2(s): I2(g): → I2(s).What are the signs (+ or -)of ΔH,ΔS,and ΔG for this process?

For the reaction N2(g)+ 2 O2(g)→ 2 NO2(g),ΔH° = 66.4 kJ/mol and ΔS° = -121.5 J/K.Is there a temperature at which the spontaneity of this reaction be changed,either from spontaneous to nonspontaneous or nonspontaneous to spontaneous? If so,estimate the temperature.

Predict the sign of ΔS for each of the following processes,which occur at constant temperature. I.The volume of 2.0 moles of O2(g)increases from 44 L to 52 L. II.The pressure of 2.0 moles of O2(g)increases from 1.0 atm to 1.2 atm.

Which is the lowest at 25°C?

Chemical Tools: Experimentation and Measurement

Atoms, molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Periodicity and the Electronic Structure of Atoms

Ionic Compounds: Periodic Trends and Bonding

Covalent Bonding and Electron-Dot Structures

Covalent Compounds: Bonding Theories and Molecular Structure

Thermochemistry: Chemical Energy

Gases: Their Properties and Behavior

Liquids, solids, and Phase Changes

Solutions and Their Properties

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Electrochemistry

Nuclear Chemistry

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

The Main-Group Elements

Connections to Organic and Biological Chemistry

Filters

At 25°C,ΔG° = -198 kJ for the reaction,NO(g)+ O₃(g)⇌ NO₂(g)+ O₂(g). Calculate ΔG under the following conditions:

Predict the sign of ΔS of the system for both of the following. I.2 C(graphite)+ O₂(g)→ 2 CO(g) II.C₄H₁₀(g)→ C₄H₁₀(l)

The figure represents the spontaneous deposition of iodine in which iodine vapor,I₂(g),becomes crystalline iodine solid I₂(s): I₂(g): → I₂(s).What are the signs (+ or -)of ΔH,ΔS,and ΔG for this process?

For the reaction N₂(g)+ 2 O₂(g)→ 2 NO₂(g),ΔH° = 66.4 kJ/mol and ΔS° = -121.5 J/K.Is there a temperature at which the spontaneity of this reaction be changed,either from spontaneous to nonspontaneous or nonspontaneous to spontaneous? If so,estimate the temperature.

Predict the sign of ΔS for each of the following processes,which occur at constant temperature. I.The volume of 2.0 moles of O₂(g)increases from 44 L to 52 L. II.The pressure of 2.0 moles of O₂(g)increases from 1.0 atm to 1.2 atm.