Question 1

The water-gas shift reaction plays an important role in the production of clean fuel from coal.

Accepted Answer

The answer of The water-gas shift reaction plays an important...

Question 2

Which relationship or statement best describes $\Delta$S $\degree$ for the following reaction?

Accepted Answer

A)  ($\Delta$S $\degree$$\approx$0) 
B) ( $\Delta$S $\degree$ 0) 
D) ( $\Delta$S $\degree$ = $\Delta$H $\degree$/T) 
E)  More information is needed to make a reasonable prediction. 
A)  ($\Delta$S $\degree$$\approx$0) 
B) ( $\Delta$S $\degree$ 0) 
D) ( $\Delta$S $\degree$ = $\Delta$H $\degree$/T) 
E)  More information is needed to make a reasonable prediction.

Question 3

The higher the pressure of a gas sample, the greater is its entropy.

Accepted Answer

A) True 
 B)False

Question 4

Calculate $\Delta$G$\degree$for the reaction of ammonia with fluorine.

Accepted Answer

A)  179.1 kJ 
B)  -179.1 kJ 
C)  1539.7 kJ 
D)  -1539.7 kJ 
E)  None of these choices is correct. 
A)  179.1 kJ 
B)  -179.1 kJ 
C)  1539.7 kJ 
D)  -1539.7 kJ 
E)  None of these choices is correct.

Question 5

Which relationship or statement best describes $\Delta$S$\degree$ for the following reaction?

Accepted Answer

A)  ($\Delta$S$\degree$F$\approx$ 0) 
B)  ($\Delta$S$\degree$  0) 
D) ( $\Delta$S$\degree$ = $\Delta$H$\degree$/T) 
E)  More information is needed to make a reasonable prediction. 
A)  ($\Delta$S$\degree$F$\approx$ 0) 
B)  ($\Delta$S$\degree$  0) 
D) ( $\Delta$S$\degree$ = $\Delta$H$\degree$/T) 
E)  More information is needed to make a reasonable prediction.

Question 6

A sample of water is heated at a constant pressure of one atmosphere. Initially, the sample is ice at 260 K, and at the end the sample consists of steam at 400 K. In which of the following 5 K temperature intervals would there be the greatest increase in the entropy of the sample?

Accepted Answer

A)  from 260 K to 265 K 
B)  from 275 K to 280 K 
C)  from 360 K to 365 K 
D)  370 K to 375 K 
E)  from 395 K to 400 K 
A)  from 260 K to 265 K 
B)  from 275 K to 280 K 
C)  from 360 K to 365 K 
D)  370 K to 375 K 
E)  from 395 K to 400 K

Question 7

Which relationship or statement best describes $\Delta$S$\degree$for the following reaction?

Accepted Answer

A)  ($\Delta$S$\degree$$\approx$ 0) 
B)  ($\Delta$S$\degree$  0) 
D)  ($\Delta$S$\degree$ = $\Delta$H$\degree$/T) 
E)  More information is needed to make a reasonable prediction. 
A)  ($\Delta$S$\degree$$\approx$ 0) 
B)  ($\Delta$S$\degree$  0) 
D)  ($\Delta$S$\degree$ = $\Delta$H$\degree$/T) 
E)  More information is needed to make a reasonable prediction.

Question 8

For a process with $\Delta$S < 0, which one of the following statements is correct?

Accepted Answer

A)  The process will definitely be spontaneous if $\Delta$H surr > 0. 
A)  The process will definitely be spontaneous if $\Delta$H surr > 0.

Question 9

In order for a process to be spontaneous,

Accepted Answer

A)  the entropy of the system must increase. 
B)  the entropy of the surroundings must increase. 
C)  the entropy of the universe must decrease. 
D)  the entropy of the surroundings must decrease. 
E)  the entropy change of the surroundings plus the entropy change of the system must be positive. 
A)  the entropy of the system must increase. 
B)  the entropy of the surroundings must increase. 
C)  the entropy of the universe must decrease. 
D)  the entropy of the surroundings must decrease. 
E)  the entropy change of the surroundings plus the entropy change of the system must be positive.

Question 10

Which one of the following changes of state increases the entropy of the system?

Accepted Answer

A)  condensation 
B)  cooling a gas 
C)  freezing 
D)  crystallization 
E)  sublimation 
A)  condensation 
B)  cooling a gas 
C)  freezing 
D)  crystallization 
E)  sublimation

Question 11

The entropy of one mole of oxygen gas in a 0.5-L container is less than it would be in a 22.4-L container at the same temperature.

Accepted Answer

A) True 
 B)False

Question 12

Use the thermodynamic data at 298 K below to determine the Ksp for barium carbonate, BaCO3 at this temperature.

Accepted Answer

A)  5.86 
B)  6.30 * 108 
C)  1.59 * 10¯9 
D)  5.47 * 10¯21 
E)  2.18 * 10¯27 
A)  5.86 
B)  6.30 * 108 
C)  1.59 * 10¯9 
D)  5.47 * 10¯21 
E)  2.18 * 10¯27

Question 13

For a reaction at equilibrium, $\Delta$Suniv = 0.

Accepted Answer

A) True 
 B)False

Question 14

Which relationship or statement best describes $\Delta$S $\degree$ for the following reaction?

Accepted Answer

A)  ($\Delta$S $\degree$$\approx$ 0 
B)  ($\Delta$S $\degree$  0) 
D) ( $\Delta$S $\degree$ = $\Delta$H $\degree$/T) 
E)  More information is needed to make a reasonable prediction. 
A)  ($\Delta$S $\degree$$\approx$ 0 
B)  ($\Delta$S $\degree$  0) 
D) ( $\Delta$S $\degree$ = $\Delta$H $\degree$/T) 
E)  More information is needed to make a reasonable prediction.

Question 15

As a chemical reaction proceeds toward equilibrium, the free energy of the system decreases.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following should have the greatest molar entropy at 298 K?

Accepted Answer

A)  CH4(g) 
B)  H2O(l) 
C)  NaCl(s) 
D)  N2O4(g) 
E)  H2(g) 
A)  CH4(g) 
B)  H2O(l) 
C)  NaCl(s) 
D)  N2O4(g) 
E)  H2(g)

Question 17

The second law of thermodynamics tells us that

Accepted Answer

A)  the entropy of the universe is constant. 
B)  entropy is neither created nor destroyed. 
C)  the universe proceeds towards a state of lower entropy. 
D)  the universe proceeds towards a state of higher entropy. 
E)  the universe cannot create entropy. 
A)  the entropy of the universe is constant. 
B)  entropy is neither created nor destroyed. 
C)  the universe proceeds towards a state of lower entropy. 
D)  the universe proceeds towards a state of higher entropy. 
E)  the universe cannot create entropy.

Question 18

The temperature at which the following process reaches equilibrium at 1.0 atm is the normal boiling point of hydrogen peroxide.

Accepted Answer

The answer of The temperature at which the following process...

Question 19

Hydrogen sulfide decomposes according to the following reaction:   For this reaction at 298 K, $\Delta$S$\degree$ = 78.1 J/K, $\Delta$H$\degree$ = 169.4 kJ, and $\Delta$G$\degree$ = 146.1 kJ. What is the value of $\Delta$G$\degree$ at 900 K?

Accepted Answer

A)  -69,881 kJ 
B)  48.4 kJ 
C)  99.1 kJ 
D)  240 kJ 
E)  441 kJ 
A)  -69,881 kJ 
B)  48.4 kJ 
C)  99.1 kJ 
D)  240 kJ 
E)  441 kJ

Question 20

The term "microstate" refers to the energy state of a single molecule in a system of many molecules.

Accepted Answer

A) True 
 B)False

Exam 20: Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions

The water-gas shift reaction plays an important role in the production of clean fuel from coal.

Which relationship or statement best describes Δ\DeltaΔ S °\degree° for the following reaction?

The higher the pressure of a gas sample, the greater is its entropy.

Calculate Δ\DeltaΔ G °\degree° for the reaction of ammonia with fluorine.

Which relationship or statement best describes Δ\DeltaΔ S °\degree° for the following reaction?

A sample of water is heated at a constant pressure of one atmosphere. Initially, the sample is ice at 260 K, and at the end the sample consists of steam at 400 K. In which of the following 5 K temperature intervals would there be the greatest increase in the entropy of the sample?

Which relationship or statement best describes Δ\DeltaΔ S °\degree° for the following reaction?

For a process with Δ\DeltaΔ S < 0, which one of the following statements is correct?

In order for a process to be spontaneous,

Which one of the following changes of state increases the entropy of the system?

The entropy of one mole of oxygen gas in a 0.5-L container is less than it would be in a 22.4-L container at the same temperature.

Use the thermodynamic data at 298 K below to determine the Ksp for barium carbonate, BaCO3 at this temperature.

For a reaction at equilibrium, Δ\DeltaΔ Suniv = 0.

Which relationship or statement best describes Δ\DeltaΔ S °\degree° for the following reaction?

As a chemical reaction proceeds toward equilibrium, the free energy of the system decreases.

Which of the following should have the greatest molar entropy at 298 K?

The second law of thermodynamics tells us that

The temperature at which the following process reaches equilibrium at 1.0 atm is the normal boiling point of hydrogen peroxide.

Hydrogen sulfide decomposes according to the following reaction: For this reaction at 298 K, Δ\DeltaΔ S °\degree° = 78.1 J/K, Δ\DeltaΔ H °\degree° = 169.4 kJ, and Δ\DeltaΔ G °\degree° = 146.1 kJ. What is the value of Δ\DeltaΔ G °\degree° at 900 K?

The term "microstate" refers to the energy state of a single molecule in a system of many molecules.

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Which relationship or statement best describes $\Delta$ S $\degree$ for the following reaction? $Which relationship or statement best describes \Delta S \degree for the following reaction?$

Calculate $\Delta$ G $\degree$ for the reaction of ammonia with fluorine. $Calculate \Delta G \degree for the reaction of ammonia with fluorine.$ $Calculate \Delta G \degree for the reaction of ammonia with fluorine.$

Which relationship or statement best describes $\Delta$ S $\degree$ for the following reaction? $Which relationship or statement best describes \Delta S \degree for the following reaction?$

Which relationship or statement best describes $\Delta$ S $\degree$ for the following reaction? $Which relationship or statement best describes \Delta S \degree for the following reaction?$

For a process with $\Delta$ S < 0, which one of the following statements is correct?

Use the thermodynamic data at 298 K below to determine the K_sp for barium carbonate, BaCO₃ at this temperature.

For a reaction at equilibrium, $\Delta$ S_univ = 0.

Which relationship or statement best describes $\Delta$ S $\degree$ for the following reaction? $Which relationship or statement best describes \Delta S \degree for the following reaction?$