Question 1

Choose the substance with the higher entropy per mole at a given temperature: O2(g)at 5 atm or O2(g)at 0.5 atm.

Accepted Answer

Question 2

At 700 K, the equilibrium constant for the reaction CO(g)+ H2O(g) $\rarr$ CO2(g)+ H2(g)is 5.10. What is $\Delta$G° for this reaction at this temperature?

Accepted Answer

The answer of At 700 K, the equilibrium constant for...

Question 3

For a certain reaction, $\Delta$G° = 87 kJ/mol, $\Delta$H° = 100 kJ/mol at STP. At what temperature, in K, is the reaction in equilibrium, assuming that $\Delta$S° and $\Delta$H° are temperature-independent?

Accepted Answer

The answer of For a certain reaction, $\Delta$G° = 87...

Question 4

The normal freezing point of ammonia is -78°C. Predict the signs of $\Delta$H, $\Delta$S, and $\Delta$G for ammonia when it freezes at -80°C and 1 atm: NH3(l) $\rarr$  NH3(s) $\Delta$H $\Delta$S $\Delta$G

Accepted Answer

A) - - 0 
B) - + - 
C) + - + 
D) + + 0 
E) - - - 
A) - - 0 
B) - + - 
C) + - + 
D) + + 0 
E) - - -

Question 5

The following reaction is nonspontaneous at 25°C:
Cu2O(s) $\rarr$ 2Cu(s)+ 1/2O2(g), $\Delta$G° = 141 kJ/mol
If $\Delta$S° = 75.8 J/K·mol, what is the lowest temperature at which the reaction will be spontaneous?

Accepted Answer

The answer of The following reaction is nonspontaneous at 25°C:
Cu2O(s)...

Question 6

For a given substance the entropy always increases in the following order:
S (gas)< S (liq)< S (solid).

Accepted Answer

A) True 
 B)False

Question 7

Consider the reaction CO(g)+ 2H2(g) $\rarr$CH3OH(l)at 25°C.
$\Delta$G°f (CO)= -137.3 kJ/mol
$\Delta$G°f (CH3OH)= -166.3 kJ/mol
$\Delta$H°f (CO)= -110.5 kJ/mol
$\Delta$H°f (CH3OH)= -238.7 kJ/mol
S°(CO)= 197.9 J/K·mol
S°(CH3OH)= 126.8 J/K·mol
Calculate $\Delta$G° at 25°C.

Accepted Answer

The answer of Consider the reaction CO(g)+ 2H2(g) $\rarr$CH3OH(l)at 25°C.
$\Delta$G°f...

Question 8

Dissolving an ionic solid in water always results in an increase in entropy.

Accepted Answer

A) True 
 B)False

Question 9

For the reaction SbCl5(g) $\rarr$ SbCl3(g)+ Cl2(g),
$\Delta$G°f (SbCl5)= -334.34 kJ/mol
$\Delta$G°f (SbCl3)= -301.25 kJ/mol
$\Delta$H°f (SbCl5)= -394.34 kJ/mol
$\Delta$H°f (SbCl3)= -313.80 kJ/mol
Calculate $\Delta$G at 800 K and 1 atm pressure (assume $\Delta$S° and $\Delta$H° do not change with temperature).

Accepted Answer

The answer of For the reaction SbCl5(g) $\rarr$ SbCl3(g)+ Cl2(g),
$\Delta$G°f...

Question 10

Sulfur can be separated from lead in the mineral galena, PbS(s), by "roasting" the ore in the presence of oxygen as shown in the following reaction: 2PbS(s)+ 3O2(g) $\rarr$ 2PbO(s)+ 2SO2(g)
Calculate $\Delta$S° for this reaction using the thermodynamic data provided below.

Accepted Answer

A) -410 J/K·mol 
B) -161.5 J/K·mol 
C) -47.7 J/K·mol 
D) 21.8 J/K·mol 
E) 43.5 J/K·mol 
A) -410 J/K·mol 
B) -161.5 J/K·mol 
C) -47.7 J/K·mol 
D) 21.8 J/K·mol 
E) 43.5 J/K·mol

Question 11

Using the thermodynamic data provided below, calculate Ka2 for H2CO3(aq)at 25°.

Accepted Answer

4.59 * 10^-11

Question 12

For the reaction 3H2(g)+ N2(g) $\rarr$ 2NH3(g), Kc = 9.0 at 350°C. In what direction does this reaction proceed at 350°C under standard state conditions?

Accepted Answer

The answer of For the reaction 3H2(g)+ N2(g) $\rarr$ 2NH3(g),...

Choose the substance with the higher entropy per mole at a given temperature: O₂(g)at 5 atm or O₂(g)at 0.5 atm.

At 700 K, the equilibrium constant for the reaction CO(g)+ H₂O(g) $\rarr$ CO₂(g)+ H₂(g)is 5.10. What is $\Delta$ G° for this reaction at this temperature?

For a certain reaction, $\Delta$ G° = 87 kJ/mol, $\Delta$ H° = 100 kJ/mol at STP. At what temperature, in K, is the reaction in equilibrium, assuming that $\Delta$ S° and $\Delta$ H° are temperature-independent?

The normal freezing point of ammonia is -78°C. Predict the signs of $\Delta$ H, $\Delta$ S, and $\Delta$ G for ammonia when it freezes at -80°C and 1 atm: NH₃(l) $\rarr$ NH₃(s) $\Delta$ H $\Delta$ S $\Delta$ G

The following reaction is nonspontaneous at 25°C: Cu₂O(s) $\rarr$ 2Cu(s)+ ¹/₂O₂(g), $\Delta$ G° = 141 kJ/mol If $\Delta$ S° = 75.8 J/K·mol, what is the lowest temperature at which the reaction will be spontaneous?

For a given substance the entropy always increases in the following order: S (gas)< S (liq)< S (solid).

Dissolving an ionic solid in water always results in an increase in entropy.

Using the thermodynamic data provided below, calculate K_a2 for H₂CO₃(aq)at 25°.

For the reaction 3H₂(g)+ N₂(g) $\rarr$ 2NH₃(g), K_c = 9.0 at 350°C. In what direction does this reaction proceed at 350°C under standard state conditions?

Introduction

Atoms, Molecules, and Ions

Stoichiometry

Reactions in Aqueous Solution

Gases

Energy Relationships in Chemical Reactions

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

Exam 18: Thermodynamics

Choose the substance with the higher entropy per mole at a given temperature: O2(g)at 5 atm or O2(g)at 0.5 atm.

At 700 K, the equilibrium constant for the reaction CO(g)+ H2O(g) →\rarr→ CO2(g)+ H2(g)is 5.10. What is Δ\DeltaΔ G° for this reaction at this temperature?

For a certain reaction, Δ\DeltaΔ G° = 87 kJ/mol, Δ\DeltaΔ H° = 100 kJ/mol at STP. At what temperature, in K, is the reaction in equilibrium, assuming that Δ\DeltaΔ S° and Δ\DeltaΔ H° are temperature-independent?

The normal freezing point of ammonia is -78°C. Predict the signs of Δ\DeltaΔ H, Δ\DeltaΔ S, and Δ\DeltaΔ G for ammonia when it freezes at -80°C and 1 atm: NH3(l) →\rarr→ NH3(s) Δ\DeltaΔ H Δ\DeltaΔ S Δ\DeltaΔ G

The following reaction is nonspontaneous at 25°C: Cu2O(s) →\rarr→ 2Cu(s)+ 1/2O2(g), Δ\DeltaΔ G° = 141 kJ/mol If Δ\DeltaΔ S° = 75.8 J/K·mol, what is the lowest temperature at which the reaction will be spontaneous?

For a given substance the entropy always increases in the following order: S (gas)< S (liq)< S (solid).

Dissolving an ionic solid in water always results in an increase in entropy.

Sulfur can be separated from lead in the mineral galena, PbS(s), by "roasting" the ore in the presence of oxygen as shown in the following reaction: 2PbS(s)+ 3O2(g) →\rarr→ 2PbO(s)+ 2SO2(g) Calculate Δ\DeltaΔ S° for this reaction using the thermodynamic data provided below.

Using the thermodynamic data provided below, calculate Ka2 for H2CO3(aq)at 25°.

For the reaction 3H2(g)+ N2(g) →\rarr→ 2NH3(g), Kc = 9.0 at 350°C. In what direction does this reaction proceed at 350°C under standard state conditions?

Introduction

Atoms, Molecules, and Ions

Stoichiometry

Reactions in Aqueous Solution

Gases

Energy Relationships in Chemical Reactions

The Electronic Structure of Atoms

The Periodic Table

Chemical Bonding I: the Covalent Bond

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Introduction to Organic Chemistry

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Redox Reactions and Electrochemistry

The Chemistry of Coordination Compounds

Nuclear Chemistry

Organic Polymerssynthetic and Natural

Filters

Choose the substance with the higher entropy per mole at a given temperature: O₂(g)at 5 atm or O₂(g)at 0.5 atm.

At 700 K, the equilibrium constant for the reaction CO(g)+ H₂O(g) $\rarr$ CO₂(g)+ H₂(g)is 5.10. What is $\Delta$ G° for this reaction at this temperature?

For a certain reaction, $\Delta$ G° = 87 kJ/mol, $\Delta$ H° = 100 kJ/mol at STP. At what temperature, in K, is the reaction in equilibrium, assuming that $\Delta$ S° and $\Delta$ H° are temperature-independent?

The normal freezing point of ammonia is -78°C. Predict the signs of $\Delta$ H, $\Delta$ S, and $\Delta$ G for ammonia when it freezes at -80°C and 1 atm: NH₃(l) $\rarr$ NH₃(s) $\Delta$ H $\Delta$ S $\Delta$ G

The following reaction is nonspontaneous at 25°C: Cu₂O(s) $\rarr$ 2Cu(s)+ ¹/₂O₂(g), $\Delta$ G° = 141 kJ/mol If $\Delta$ S° = 75.8 J/K·mol, what is the lowest temperature at which the reaction will be spontaneous?

Using the thermodynamic data provided below, calculate K_a2 for H₂CO₃(aq)at 25°.

For the reaction 3H₂(g)+ N₂(g) $\rarr$ 2NH₃(g), K_c = 9.0 at 350°C. In what direction does this reaction proceed at 350°C under standard state conditions?