Question 1

A reversible change produces the maximum amount of ________ that can be achieved by the system on the surroundings.

Accepted Answer

The answer of A reversible change produces the maximum amount...

Question 2

The value of ΔG° at 25 °C for the oxidation of solid elemental sulfur to gaseous sulfur trioxide, 2S (s, rhombic)+ 3O2 (g)→ 2SO3 (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

Consider the reaction: NH3 (g)+ HCl (g)$\rarr$NHO4Cl (s)
Given the following table of thermodynamic data at 298 K:

The value of K for the reaction at 25°C is __________.

Accepted Answer

A) 150 
B) 9.2 × 1015 
C) 8.4 × 104 
D) 1.1 × 10-16 
E) 1.4 × 108 
A) 150 
B) 9.2 × 1015 
C) 8.4 × 104 
D) 1.1 × 10-16 
E) 1.4 × 108

Question 4

The value of ΔG° at 373 K for the oxidation of solid elemental sulfur to gaseous sulfur dioxide, S (s, rhombic)+ O2 (g)→ SO2 (g)
Is __________ kJ/mol. At 298 K, ΔH° for this reaction is -269.9 kJ/mol, and ΔS° is +11.6 J/K.

Accepted Answer

A) -300.4 
B) +300.4 
C) -4,597 
D) +4,597 
E) -274.2 
A) -300.4 
B) +300.4 
C) -4,597 
D) +4,597 
E) -274.2

Question 5

The value of ΔG° at 25 °C for the oxidation of solid elemental sulfur to gaseous sulfur dioxide, S (s, rhombic)+ O2(g)→ SO2 (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 6

The value of ΔH° for the formation of calcium chloride from its constituent elements, Ca (s)+ Cl2 (g)→ CaCl2 (s)
Is __________ kJ/mol.

Accepted Answer

A) +0.00 
B) -397.9 
C) +397.9 
D) -795.8 
E) +795.8 
A) +0.00 
B) -397.9 
C) +397.9 
D) -795.8 
E) +795.8

Question 7

The thermodynamic quantity that expresses the degree of disorder in a system is __________.

Accepted Answer

A) enthalpy 
B) internal energy 
C) bond energy 
D) entropy 
E) heat flow 
A) enthalpy 
B) internal energy 
C) bond energy 
D) entropy 
E) heat flow

Question 8

The value of ΔH° for the decomposition of phosphorous trichloride into its constituent elements, 2PCl3 (g)→ P2 (g)+ 3Cl2 (g)
Is __________ kJ/mol.

Accepted Answer

A) +576.2 
B) -288.1 
C) +720.5 
D) +288.1 
E) -720.5 
A) +576.2 
B) -288.1 
C) +720.5 
D) +288.1 
E) -720.5

Question 9

Which of the following statements is false?

Accepted Answer

A) The change in entropy in a system depends on the initial and final states of the system and the path taken from one state to the other. 
B) Any irreversible process results in an overall increase in entropy. 
C) The total entropy of the universe increases in any spontaneous process. 
D) Entropy increases with the number of microstates of the system. 
A) The change in entropy in a system depends on the initial and final states of the system and the path taken from one state to the other. 
B) Any irreversible process results in an overall increase in entropy. 
C) The total entropy of the universe increases in any spontaneous process. 
D) Entropy increases with the number of microstates of the system.

Question 10

The value of ΔS° for the catalytic hydrogenation of acetylene to ethene, C2H2 (g)+ H2 (g)→ C2H4 (g)
Is __________ J/K∙ mol.

Accepted Answer

A) +18.6 
B) +550.8 
C) +112.0 
D) -112.0 
E) -18.6 
A) +18.6 
B) +550.8 
C) +112.0 
D) -112.0 
E) -18.6

Question 11

The value of ΔS° for the oxidation of carbon to carbon monoxide, 2C (s, graphite)+ O2 (g)→ 2CO (g)
Is __________ J/K∙ mol. Carbon monoxide is produced in the combustion of carbon with limited oxygen.

Accepted Answer

A) -12.8 
B) +408.6 
C) -408.6 
D) +179.4 
E) +395.8 
A) -12.8 
B) +408.6 
C) -408.6 
D) +179.4 
E) +395.8

Question 12

The normal boiling point of methanol is 64.7°C and the molar enthalpy of vaporization if 71.8 kJ/mol. The value of ΔS when 2.15 mol of CH3OH (l)vaporizes at 64.7°C is __________ J/K.

Accepted Answer

A) 0.457 
B) 5.21 × 107 
C) 457 
D) 2.39 × 103 
E) 2.39 
A) 0.457 
B) 5.21 × 107 
C) 457 
D) 2.39 × 103 
E) 2.39

Question 13

Calculate ΔG° (in kJ/mol)for the following reaction at 1 atm and 25°C:
C2H6 (g)+ O2 (g)→ CO2 (g)+ H2O (l)(unbalanced)
ΔHf° C2H6 (g)= -84.7 kJ/mol; S∘C2H6 (g)= 229.5 J/K ∙ mol;
ΔHf° CO2 (g)= -393.5 kJ/mol; S∘CO2 (g)= 213.6 J/K ∙ mol;
ΔHf° H2O (l)= -285.8 kJ/mol; S∘H2O (l)= 69.9 J/K ∙ mol;
S∘O2 (g)= 205.0 J/K ∙ mol

Accepted Answer

Question 14

The combustion of acetylene in the presence of excess oxygen yields carbon dioxide and water: 2C2H2 (g)+ 5O2 (g)→ 4CO2 (g)+ 2H2O (l)
The value of ΔS° for this reaction is __________ J/K∙ mol.

Accepted Answer

A) +689.3 
B) +122.3 
C) +432.4 
D) -122.3 
E) -432.4 
A) +689.3 
B) +122.3 
C) +432.4 
D) -122.3 
E) -432.4

Question 15

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 16

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 17

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 18

The value of ΔG° for a reaction conducted at 25°C is 2.8 kJ/mol. The equilibrium constant for a reaction is __________ at this temperature?

Accepted Answer

A) 1.13 
B) -4.2 
C) 0.32 
D) -1.13 
E) More information is needed. 
A) 1.13 
B) -4.2 
C) 0.32 
D) -1.13 
E) More information is needed.

Question 19

The value of ΔG° at 25°C for the decomposition of POCl3 into its constituent elements, 2POCl3 (g)→ P2 (g)+ O2 (g)+ 3Cl2 (g)
Is __________ kJ/mol.

Accepted Answer

A) -1108.7 
B) +1108.7 
C) -606.2 
D) +606.2 
E) -1,005 
A) -1108.7 
B) +1108.7 
C) -606.2 
D) +606.2 
E) -1,005

Question 20

The value of ΔH° for the decomposition of gaseous sulfur trioxide to its component elements, 2SO3 (g)→ 2S (s, rhombic)+ 3O2 (g)
Is __________ kJ/mol.

Accepted Answer

A) +790.4 
B) -790.4 
C) +395.2 
D) -395.2 
E) +105.1 
A) +790.4 
B) -790.4 
C) +395.2 
D) -395.2 
E) +105.1

Exam 19: Chemical Thermodynamics

A reversible change produces the maximum amount of ________ that can be achieved by the system on the surroundings.

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

Consider the reaction: NH3 (g)+ HCl (g) →\rarr→ NHO4Cl (s) Given the following table of thermodynamic data at 298 K: The value of K for the reaction at 25°C is __________.

The value of ΔG° at 373 K for the oxidation of solid elemental sulfur to gaseous sulfur dioxide, S (s, rhombic)+ O2 (g)→ SO2 (g) Is __________ kJ/mol. At 298 K, ΔH° for this reaction is -269.9 kJ/mol, and ΔS° is +11.6 J/K.

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

The value of ΔH° for the formation of calcium chloride from its constituent elements, Ca (s)+ Cl2 (g)→ CaCl2 (s) Is __________ kJ/mol.

The thermodynamic quantity that expresses the degree of disorder in a system is __________.

The value of ΔH° for the decomposition of phosphorous trichloride into its constituent elements, 2PCl3 (g)→ P2 (g)+ 3Cl2 (g) Is __________ kJ/mol.

Which of the following statements is false?

The value of ΔS° for the catalytic hydrogenation of acetylene to ethene, C2H2 (g)+ H2 (g)→ C2H4 (g) Is __________ J/K∙ mol.

The value of ΔS° for the oxidation of carbon to carbon monoxide, 2C (s, graphite)+ O2 (g)→ 2CO (g) Is __________ J/K∙ mol. Carbon monoxide is produced in the combustion of carbon with limited oxygen.

The normal boiling point of methanol is 64.7°C and the molar enthalpy of vaporization if 71.8 kJ/mol. The value of ΔS when 2.15 mol of CH3OH (l)vaporizes at 64.7°C is __________ J/K.

The combustion of acetylene in the presence of excess oxygen yields carbon dioxide and water: 2C2H2 (g)+ 5O2 (g)→ 4CO2 (g)+ 2H2O (l) The value of ΔS° for this reaction is __________ J/K∙ mol.

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

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° for a reaction conducted at 25°C is 2.8 kJ/mol. The equilibrium constant for a reaction is __________ at this temperature?

The value of ΔG° at 25°C for the decomposition of POCl3 into its constituent elements, 2POCl3 (g)→ P2 (g)+ O2 (g)+ 3Cl2 (g) Is __________ kJ/mol.

The value of ΔH° for the decomposition of gaseous sulfur trioxide to its component elements, 2SO3 (g)→ 2S (s, rhombic)+ 3O2 (g) Is __________ kJ/mol.

Introduction: Matter and Measurement

Atoms, Molecules, and Ions

Stoichiometry: Calculations With Chemical Formulas and Equations

Aqueous Reactions and Solution Stoichiometry

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 oxidation of solid elemental sulfur to gaseous sulfur trioxide, 2S (s, rhombic)+ 3O₂ (g)→ 2SO₃ (g) Is __________ kJ/mol.

The value of ΔG° at 373 K for the oxidation of solid elemental sulfur to gaseous sulfur dioxide, S (s, rhombic)+ O₂ (g)→ SO₂ (g) Is __________ kJ/mol. At 298 K, ΔH° for this reaction is -269.9 kJ/mol, and ΔS° is +11.6 J/K.

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

The value of ΔH° for the formation of calcium chloride from its constituent elements, Ca (s)+ Cl₂ (g)→ CaCl₂ (s) Is __________ kJ/mol.

The value of ΔH° for the decomposition of phosphorous trichloride into its constituent elements, 2PCl₃ (g)→ P₂ (g)+ 3Cl₂ (g) Is __________ kJ/mol.

The value of ΔS° for the catalytic hydrogenation of acetylene to ethene, C₂H₂ (g)+ H₂ (g)→ C₂H₄ (g) Is __________ J/K∙ mol.

The value of ΔS° for the oxidation of carbon to carbon monoxide, 2C (s, graphite)+ O₂ (g)→ 2CO (g) Is __________ J/K∙ mol. Carbon monoxide is produced in the combustion of carbon with limited oxygen.

The normal boiling point of methanol is 64.7°C and the molar enthalpy of vaporization if 71.8 kJ/mol. The value of ΔS when 2.15 mol of CH₃OH (l)vaporizes at 64.7°C is __________ J/K.

The combustion of acetylene in the presence of excess oxygen yields carbon dioxide and water: 2C₂H₂ (g)+ 5O₂ (g)→ 4CO₂ (g)+ 2H₂O (l) The value of ΔS° for this reaction is __________ J/K∙ mol.

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 value of ΔG° at 25°C for the decomposition of POCl₃ into its constituent elements, 2POCl₃ (g)→ P₂ (g)+ O₂ (g)+ 3Cl₂ (g) Is __________ kJ/mol.

The value of ΔH° for the decomposition of gaseous sulfur trioxide to its component elements, 2SO₃ (g)→ 2S (s, rhombic)+ 3O₂ (g) Is __________ kJ/mol.