Question 1

ΔS is positive for the reaction ________.

Accepted Answer

A) 2H2 (g)+ O2 (g)→ 2H2O (g) 
B) 2NO2 (g)→ N2O4 (g) 
C) CO2 (g)→ CO2 (s) 
D) BaF2 (s)→ Ba2+ (aq)+ 2F- (aq) 
E) 2Hg (l)+ O2 (g)→ 2HgO (s) 
A) 2H2 (g)+ O2 (g)→ 2H2O (g) 
B) 2NO2 (g)→ N2O4 (g) 
C) CO2 (g)→ CO2 (s) 
D) BaF2 (s)→ Ba2+ (aq)+ 2F- (aq) 
E) 2Hg (l)+ O2 (g)→ 2HgO (s)

Question 2

The value of ΔG° at 25 °C for the decomposition of gaseous sulfur trioxide to solid elemental sulfur and gaseous oxygen, 2SO3 (g)→ 2S (s,rhombic)+ 3O2 (g)
Is ________ kJ/mol.

Accepted Answer

A) +740.8 
B) -370.4 
C) +370.4 
D) -740.8 
E) +185.2 
A) +740.8 
B) -370.4 
C) +370.4 
D) -740.8 
E) +185.2

Question 3

The entropy change accompanying any process is given by the equation:

Accepted Answer

A) ΔS = k lnWfinal 
B) ΔS = k Wfinal - k Winitial 
C) ΔS = k ln(Wfinal / Winitial) 
D) ΔS = k final - k initial 
E) ΔS = Wfinal - Winitial 
A) ΔS = k lnWfinal 
B) ΔS = k Wfinal - k Winitial 
C) ΔS = k ln(Wfinal / Winitial) 
D) ΔS = k final - k initial 
E) ΔS = Wfinal - Winitial

Question 4

The standard Gibbs free energy of formation of ________ is zero. (a)Mn (s)
(b)I2 (s)
(c)Cu (s)

Accepted Answer

A) (a)only 
B) (b)only 
C) (c)only 
D) (b)and (c) 
E) (a), (b), and (c) 
A) (a)only 
B) (b)only 
C) (c)only 
D) (b)and (c) 
E) (a), (b), and (c)

Question 5

For a given reaction,ΔS = +69.0 J/mol∙K,and the reaction is spontaneous at temperatures above the crossover temperature,   The value of   assuming that ΔH and ΔS do not vary with temperature.

Accepted Answer

A) 30.3 
B) -30.3 
C) 1.57 × 10-4 
D) -1.57 × 10-4 
E) 6.36 × 10-3 
A) 30.3 
B) -30.3 
C) 1.57 × 10-4 
D) -1.57 × 10-4 
E) 6.36 × 10-3

Question 6

The more negative ΔG° is for a given reaction,the larger the value of the corresponding equilibrium constant,K.

Accepted Answer

A) True 
 B)False

Question 7

The combustion of ethene in the presence of excess oxygen yields carbon dioxide and water: C2H4 (g)+ 3O2 (g)→ 2CO2 (g)+ 2H2O (l)
The value of ΔS° for this reaction is ________ J/K ∙ mol.

Accepted Answer

A) -267.4 
B) -140.9 
C) -347.6 
D) +347.6 
E) +140.9 
A) -267.4 
B) -140.9 
C) -347.6 
D) +347.6 
E) +140.9

Question 8

Which of the following has the largest entropy at   and atm?

Accepted Answer

A) C3H4 
B) C3H6 
C) C3H8 
D)    
E) C2H6 
A) C3H4 
B) C3H6 
C) C3H8 
D)    
E) C2H6

Question 9

Given the thermodynamic data in the table below,calculate the equilibrium constant (at 298 K)for the reaction: 2 SO2 (g)+ O2 (g)   2 SO3 (g)

Accepted Answer

A) 2.40 × 1024 
B) 1.06 
C) 1.95 
D) 3.82 × 1023 
E) More data are needed. 
A) 2.40 × 1024 
B) 1.06 
C) 1.95 
D) 3.82 × 1023 
E) More data are needed.

Question 10

ΔS is positive for the reaction ________.

Accepted Answer

A) 2 Ca (s)+ O2 (g)→ 2 CaO (s) 
B) 2 KClO3 (s)→ 2KCl (s)+ 3 O2 (g) 
C) HCl (g)+ NH3 (g)→ NH4Cl (s) 
D) Pb2+ (aq)+ 2Cl- (aq)→ PbCl2 (s) 
E) CO2 (g)→ CO2 (s) 
A) 2 Ca (s)+ O2 (g)→ 2 CaO (s) 
B) 2 KClO3 (s)→ 2KCl (s)+ 3 O2 (g) 
C) HCl (g)+ NH3 (g)→ NH4Cl (s) 
D) Pb2+ (aq)+ 2Cl- (aq)→ PbCl2 (s) 
E) CO2 (g)→ CO2 (s)

Question 11

The value of ΔS° for the reaction 2C (s,diamond)+ O2 (g)→ 2CO (g)
Is ________ J/K ∙ mol.

Accepted Answer

A) -185.9 
B) +185.9 
C) -9.5 
D) +9.5 
E) -195.7 
A) -185.9 
B) +185.9 
C) -9.5 
D) +9.5 
E) -195.7

Question 12

ΔS is negative for the reaction ________.

Accepted Answer

A) Sr(NO3)2 (aq)+ 2LiOH (aq)→ Sr(OH)2 (s)+ 2LiNO3 (aq) 
B) 2H2O (g)→ 2H2 (g)+ O2 (g) 
C) CH3OH (l)→ CH3OH (g) 
D) LiOH (aq)→ Li+ (aq)+ OH- (aq) 
E) C6H12O6 (s)→ 6C (s)+ 6H2 (g)+ 3O2 (g) 
A) Sr(NO3)2 (aq)+ 2LiOH (aq)→ Sr(OH)2 (s)+ 2LiNO3 (aq) 
B) 2H2O (g)→ 2H2 (g)+ O2 (g) 
C) CH3OH (l)→ CH3OH (g) 
D) LiOH (aq)→ Li+ (aq)+ OH- (aq) 
E) C6H12O6 (s)→ 6C (s)+ 6H2 (g)+ 3O2 (g)

Question 13

Which reaction produces an increase in the entropy of the system?

Accepted Answer

A) Ag+ (aq)+ Cl- (aq)→ AgCl (s) 
B) CO2 (s)→ CO2 (g) 
C) H2 (g)+ Cl2 (g)→ 2 HCl (g) 
D) N2 (g)+ 3 H2 (g)→ 2 NH3 (g) 
E) H2O (l)→ H2O (s) 
A) Ag+ (aq)+ Cl- (aq)→ AgCl (s) 
B) CO2 (s)→ CO2 (g) 
C) H2 (g)+ Cl2 (g)→ 2 HCl (g) 
D) N2 (g)+ 3 H2 (g)→ 2 NH3 (g) 
E) H2O (l)→ H2O (s)

Question 14

At what temperature in Kelvin will a reaction have   ? ΔH = -24.2 kJ/mol and ΔS = -55.5 J/K-mol and assume both do not vary with temperature.

Accepted Answer

A) 2.29 
B) 2293 
C) 298 
D) 436 
E) 0.436 
A) 2.29 
B) 2293 
C) 298 
D) 436 
E) 0.436

Question 15

Which one of the following statements is true about the equilibrium constant for a reaction if ΔG° for the reaction is negative?

Accepted Answer

A) K = 0 B) K = 1 C) K > 1 D) K < 1 E) More information is needed. A) K = 0 B) K = 1 C) K > 1 D) K < 1 E) More information is needed.

Question 16

The value of ΔG° at 25 °C for the following reaction: C2H4 (g)+ H2 (g)→ C2H6 (g)
Is ________ kJ/mol.At 298 K,ΔH° for this reaction is -137.5 kJ/mol,and ΔS° is +120.5 J/K.

Accepted Answer

A) -35800 
B) -173.4 
C) 35800 
D) -101.7 
E) -274.2 
A) -35800 
B) -173.4 
C) 35800 
D) -101.7 
E) -274.2

Question 17

The melting of a substance at its melting point is an isothermal process.

Accepted Answer

A) True 
 B)False

Question 18

The value of ΔG° at 25 °C for the decomposition of gaseous sulfur dioxide to solid elemental sulfur and gaseous oxygen, SO2 (g)→ S (s,rhombic)+ O2 (g)
Is ________ kJ/mol.

Accepted Answer

A) +395.2 
B) +269.9 
C) -269.9 
D) +300.4 
E) -300.4 
A) +395.2 
B) +269.9 
C) -269.9 
D) +300.4 
E) -300.4

Question 19

For a given reaction with ΔS = -50.8 J/K-mol,the ΔG = 0 at   The value of ΔH must be   assuming that ΔH and ΔS do not vary with temperature.

Accepted Answer

A) -20.1 
B) 20.1 
C) -1.29 × 10-4 
D) 1.29 × 10-4 
E) -7.78 × 10-3 
A) -20.1 
B) 20.1 
C) -1.29 × 10-4 
D) 1.29 × 10-4 
E) -7.78 × 10-3

Question 20

The value of ΔG° at 25 °C for the formation of phosphorous trichloride from its constituent elements, P2 (g)+ 3Cl2 (g)→ 2PCl3 (g)
Is ________ kJ/mol.

Accepted Answer

A) -539.2 
B) +539.2 
C) -642.9 
D) +642.9 
E) -373.3 
A) -539.2 
B) +539.2 
C) -642.9 
D) +642.9 
E) -373.3

Exam 19: Chemical Thermodynamics

ΔS is positive for the reaction ________.

The value of ΔG° at 25 °C for the decomposition of gaseous sulfur trioxide to solid elemental sulfur and gaseous oxygen, 2SO3 (g)→ 2S (s,rhombic)+ 3O2 (g) Is ________ kJ/mol.

The entropy change accompanying any process is given by the equation:

The standard Gibbs free energy of formation of ________ is zero. (a)Mn (s) (b)I2 (s) (c)Cu (s)

For a given reaction,ΔS = +69.0 J/mol∙K,and the reaction is spontaneous at temperatures above the crossover temperature, The value of assuming that ΔH and ΔS do not vary with temperature.

The more negative ΔG° is for a given reaction,the larger the value of the corresponding equilibrium constant,K.

The combustion of ethene in the presence of excess oxygen yields carbon dioxide and water: C2H4 (g)+ 3O2 (g)→ 2CO2 (g)+ 2H2O (l) The value of ΔS° for this reaction is ________ J/K ∙ mol.

Which of the following has the largest entropy at and atm?

Given the thermodynamic data in the table below,calculate the equilibrium constant (at 298 K)for the reaction: 2 SO2 (g)+ O2 (g) 2 SO3 (g)

ΔS is positive for the reaction ________.

The value of ΔS° for the reaction 2C (s,diamond)+ O2 (g)→ 2CO (g) Is ________ J/K ∙ mol.

ΔS is negative for the reaction ________.

Which reaction produces an increase in the entropy of the system?

At what temperature in Kelvin will a reaction have ? ΔH = -24.2 kJ/mol and ΔS = -55.5 J/K-mol and assume both do not vary with temperature.

Which one of the following statements is true about the equilibrium constant for a reaction if ΔG° for the reaction is negative?

The value of ΔG° at 25 °C for the following reaction: C2H4 (g)+ H2 (g)→ C2H6 (g) Is ________ kJ/mol.At 298 K,ΔH° for this reaction is -137.5 kJ/mol,and ΔS° is +120.5 J/K.

The melting of a substance at its melting point is an isothermal process.

The value of ΔG° at 25 °C for the decomposition of gaseous sulfur dioxide to solid elemental sulfur and gaseous oxygen, SO2 (g)→ S (s,rhombic)+ O2 (g) Is ________ kJ/mol.

For a given reaction with ΔS = -50.8 J/K-mol,the ΔG = 0 at The value of ΔH must be assuming that ΔH and ΔS do not vary with temperature.

The value of ΔG° at 25 °C for the formation of phosphorous trichloride from its constituent elements, P2 (g)+ 3Cl2 (g)→ 2PCl3 (g) Is ________ kJ/mol.

Introduction: Matter, energy, and Measurement

Atoms, molecules, and Ions

Chemical Reactions and Reaction Stoichiometry

Reactions in Aqueous Solution

Thermochemistry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Molecular Geometry and Bonding Theories

Gases

Liquids and Intermolecular Forces

Solids and Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Aqueous Equilibria

Chemistry of the Environment

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Transition Metals and Coordination Chemistry

The Chemistry of Life: Organic and Biological Chemistry

Filters

The value of ΔG° at 25 °C for the decomposition of gaseous sulfur trioxide to solid elemental sulfur and gaseous oxygen, 2SO₃ (g)→ 2S (s,rhombic)+ 3O₂ (g) Is ________ kJ/mol.

The standard Gibbs free energy of formation of ________ is zero. (a)Mn (s) (b)I₂ (s) (c)Cu (s)

The combustion of ethene in the presence of excess oxygen yields carbon dioxide and water: C₂H₄ (g)+ 3O₂ (g)→ 2CO₂ (g)+ 2H₂O (l) The value of ΔS° for this reaction is ________ J/K ∙ mol.

Given the thermodynamic data in the table below,calculate the equilibrium constant (at 298 K)for the reaction: 2 SO₂ (g)+ O₂ (g) 2 SO₃ (g)

The value of ΔS° for the reaction 2C (s,diamond)+ O₂ (g)→ 2CO (g) Is ________ J/K ∙ mol.

The value of ΔG° at 25 °C for the following reaction: C₂H₄ (g)+ H₂ (g)→ C₂H₆ (g) Is ________ kJ/mol.At 298 K,ΔH° for this reaction is -137.5 kJ/mol,and ΔS° is +120.5 J/K.

The value of ΔG° at 25 °C for the decomposition of gaseous sulfur dioxide to solid elemental sulfur and gaseous oxygen, SO₂ (g)→ S (s,rhombic)+ O₂ (g) Is ________ kJ/mol.

The value of ΔG° at 25 °C for the formation of phosphorous trichloride from its constituent elements, P₂(g)+ 3Cl₂ (g)→ 2PCl₃ (g) Is ________ kJ/mol.