Question 1

Using the thermodynamic data provided below, calculate Ka1 for H2CO3(aq)at 25°.

Accepted Answer

5 × 10^-7 (compared to

Question 2

Determine $\Delta$S° for the reaction SO3(g)+ H2O(l)$\rarr$H2SO4(l).

Accepted Answer

A) 169.2 J/K·mol 
B) 1343.2 J/K·mol 
C) -169.2 J/K·mol 
D) -29.4 J/K·mol 
E) 29.4 J/K·mol 
A) 169.2 J/K·mol 
B) 1343.2 J/K·mol 
C) -169.2 J/K·mol 
D) -29.4 J/K·mol 
E) 29.4 J/K·mol

Question 3

For the reaction 3H2(g)+ N2(g)    
2NH3(g), Kc = 9.0 at 350°C.What is the value of $\Delta$G at this temperature when 1.0 mol NH3, 5.0 mol N2, and 5.0 mol H2 are mixed in a 2.5 L reactor?

Accepted Answer

Question 4

The standard entropy of any pure substance is 0 J/mol.

Accepted Answer

A) True 
 B)False

Question 5

Calculate the free energy of formation of NaBr(s)given the following information:
NaBr(s)$\rarr$ Na(s)+ 1/2Br2(l), $\Delta$G° = 349 kJ/mol

Accepted Answer

Question 6

In the gas phase, methyl isocyanate (CH3NC)isomerizes to acetonitrile (CH3CN), H3C-N$\equiv$C (g)    
H3C-C$\equiv$N (g)
With $\Delta$H° = -89.5 kJ/mol and $\Delta$G° = - 73.8 kJ/mol at 25°C.Find the equilibrium constant for this reaction at 100°C.

Accepted Answer

A) 1.68 × 10-10 
B) 5.96 × 109 
C) 2.16 × 1010 
D) 4.63 × 10-11 
E) 8.64 × 1012 
A) 1.68 × 10-10 
B) 5.96 × 109 
C) 2.16 × 1010 
D) 4.63 × 10-11 
E) 8.64 × 1012

Question 7

For any pure substance, if $\Delta$Hf° = 0 and $\Delta$Gf° = 0, than S° = 0

Accepted Answer

A) True 
 B)False

Question 8

What is the free energy change for the reaction SiO2(s)+ Pb(s)$\rarr$ PbO2(s)+ Si(s)?
$\Delta$G°f (PbO2)= -217 kJ/mol
$\Delta$G°f (SiO2)= -856 kJ/mol

Accepted Answer

Question 9

Which response includes all of the following processes that are accompanied by an increase of entropy?

Accepted Answer

A) I and III 
B) II and III 
C) I, II and III 
D) II only 
E) III only 
A) I and III 
B) II and III 
C) I, II and III 
D) II only 
E) III only

Question 10

Consider the reaction CO(g)+ 2H2(g)    
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 value of the equilibrium constant (Kp)for this reaction at 25°C.

Accepted Answer

Question 11

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

Accepted Answer

2.8 × 10^-9 (compared t

Question 12

Choose the substance with the higher entropy per mole at a given temperature: Br2(l)or Br2(g).

Accepted Answer

Question 13

Which response includes all of the following processes that are accompanied by an increase in entropy? 
1)I2(s)$\rarr$I2(g)
2)2I(g)$\rarr$ I2(g)
3)2NH3(g)$\rarr$ N2(g)+ 3H2(g)
4)Mg2+(aq)+ 2OH-(aq)$\rarr$ Mg(OH)2(s)

Accepted Answer

A) 1, 2 
B) 1, 3 
C) 3, 4 
D) 3 
E) 2, 4 
A) 1, 2 
B) 1, 3 
C) 3, 4 
D) 3 
E) 2, 4

Question 14

Choose the substance with the higher entropy per mole at a given temperature: 1 mole of N2(g)in a 22.4 L container or 1 mole of N2(g)in a 2.24 L container.

Accepted Answer

1 mole of

Question 15

The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.

Accepted Answer

A) True 
 B)False

Question 16

For the reaction SbCl5(g)    
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
Will this reaction proceed spontaneously at 298 K and 1 atm pressure?

Accepted Answer

Question 17

Find the temperature at which Kp = 42.0 for the reaction H2(g)+ I2(g)     2HI(g).[Given: at 25°C, for H2(g), $\Delta$H°f = 0, S° = 131.0 J/mol·K; for I2(g), $\Delta$H°f = 62.26 kJ/mol, S° = 260.6 J/mol·K; for HI(g), $\Delta$H°f = 25.9 kJ/mol, S° = 206.3 J/mol·K; assume that $\Delta$H° and $\Delta$S° are independent of temperature.]

Accepted Answer

A) 1040 K 
B) 168 K 
C) 539 K 
D) 1400 K 
E) 34,200 K 
A) 1040 K 
B) 168 K 
C) 539 K 
D) 1400 K 
E) 34,200 K

Question 18

Choose the substance with the higher entropy per mole at a given temperature: CO2(g)or CO2(aq).

Accepted Answer

Question 19

Arrange the following substances in the order of increasing entropy at 25°C. HF(g), NaF(s), SiF4(g), SiH4(g), Al(s)
Lowest $\rarr$ highest

Accepted Answer

A) SiF4(g)4(g)4(g)4(g) 
C) Al(s)4(g)4(g) 
D) Al(s)4(g)4(g) 
E) NaF(s)4(g)4(g) 
A) SiF4(g)4(g)4(g)4(g) 
C) Al(s)4(g)4(g) 
D) Al(s)4(g)4(g) 
E) NaF(s)4(g)4(g)

Question 20

Which of the following processes would be accompanied by a decrease in entropy?

Accepted Answer

A) H2O(s)$\rarr$ H2O(g) 
B) H2O(l)$\rarr$ H2O(g) 
C) H2O(s)$\rarr$H2O(l) 
D) H2O(g)$\rarr$ H2O(s) 
E) H2O(l, 50°
C) $\rarr$ H2O(l, 75°
C)  
A) H2O(s)$\rarr$ H2O(g) 
B) H2O(l)$\rarr$ H2O(g) 
C) H2O(s)$\rarr$H2O(l) 
D) H2O(g)$\rarr$ H2O(s) 
E) H2O(l, 50°
C) $\rarr$ H2O(l, 75°
C)

Using the thermodynamic data provided below, calculate K_a1 for H₂CO₃(aq)at 25°.

Determine $\Delta$ S° for the reaction SO₃(g)+ H₂O(l) $\rarr$ H₂SO₄(l). $Determine \Delta S° for the reaction SO<sub>3</sub>(g)+ H<sub>2</sub>O(l) \rarr H<sub>2</sub>SO<sub>4</sub>(l).$

The standard entropy of any pure substance is 0 J/mol.

Calculate the free energy of formation of NaBr(s)given the following information: NaBr(s) $\rarr$ Na(s)+ ¹/₂Br₂(l), $\Delta$ G° = 349 kJ/mol

For any pure substance, if $\Delta$ H_f° = 0 and $\Delta$ G_f° = 0, than S° = 0

What is the free energy change for the reaction SiO₂(s)+ Pb(s) $\rarr$ PbO₂(s)+ Si(s)? $\Delta$ G°_f (PbO₂)= -217 kJ/mol $\Delta$ G°_f (SiO₂)= -856 kJ/mol

Which response includes all of the following processes that are accompanied by an increase of entropy?

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

Choose the substance with the higher entropy per mole at a given temperature: Br₂(l)or Br₂(g).

Which response includes all of the following processes that are accompanied by an increase in entropy? 1)I₂(s) $\rarr$ I₂(g) 2)2I(g) $\rarr$ I₂(g) 3)2NH₃(g) $\rarr$ N₂(g)+ 3H₂(g) 4)Mg²⁺(aq)+ 2OH^-(aq) $\rarr$ Mg(OH)₂(s)

Choose the substance with the higher entropy per mole at a given temperature: 1 mole of N₂(g)in a 22.4 L container or 1 mole of N₂(g)in a 2.24 L container.

The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.

Choose the substance with the higher entropy per mole at a given temperature: CO₂(g)or CO₂(aq).

Arrange the following substances in the order of increasing entropy at 25°C. HF(g), NaF(s), SiF₄(g), SiH₄(g), Al(s) Lowest $\rarr$ highest

Which of the following processes would be accompanied by a decrease in entropy?

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Reactions in Aqueous Solutions

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Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

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Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

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Exam 17: Entropy Free Energy and Equilibrium

Using the thermodynamic data provided below, calculate Ka1 for H2CO3(aq)at 25°.

Determine Δ\DeltaΔ S° for the reaction SO3(g)+ H2O(l) →\rarr→ H2SO4(l).

For the reaction 3H2(g)+ N2(g) 2NH3(g), Kc = 9.0 at 350°C.What is the value of Δ\DeltaΔ G at this temperature when 1.0 mol NH3, 5.0 mol N2, and 5.0 mol H2 are mixed in a 2.5 L reactor?

The standard entropy of any pure substance is 0 J/mol.

Calculate the free energy of formation of NaBr(s)given the following information: NaBr(s) →\rarr→ Na(s)+ 1/2Br2(l), Δ\DeltaΔ G° = 349 kJ/mol

In the gas phase, methyl isocyanate (CH3NC)isomerizes to acetonitrile (CH3CN), H3C-N ≡\equiv≡ C (g) H3C-C ≡\equiv≡ N (g) With Δ\DeltaΔ H° = -89.5 kJ/mol and Δ\DeltaΔ G° = - 73.8 kJ/mol at 25°C.Find the equilibrium constant for this reaction at 100°C.

For any pure substance, if Δ\DeltaΔ Hf° = 0 and Δ\DeltaΔ Gf° = 0, than S° = 0

What is the free energy change for the reaction SiO2(s)+ Pb(s) →\rarr→ PbO2(s)+ Si(s)? Δ\DeltaΔ G°f (PbO2)= -217 kJ/mol Δ\DeltaΔ G°f (SiO2)= -856 kJ/mol

Which response includes all of the following processes that are accompanied by an increase of entropy?

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

Choose the substance with the higher entropy per mole at a given temperature: Br2(l)or Br2(g).

Which response includes all of the following processes that are accompanied by an increase in entropy? 1)I2(s) →\rarr→ I2(g) 2)2I(g) →\rarr→ I2(g) 3)2NH3(g) →\rarr→ N2(g)+ 3H2(g) 4)Mg2+(aq)+ 2OH-(aq) →\rarr→ Mg(OH)2(s)

Choose the substance with the higher entropy per mole at a given temperature: 1 mole of N2(g)in a 22.4 L container or 1 mole of N2(g)in a 2.24 L container.

The entropy of a perfectly ordered crystalline substance at 0 K is 0 J/mol.

For the reaction SbCl5(g) SbCl3(g)+ Cl2(g), Δ\DeltaΔ G°f (SbCl5)= -334.34 kJ/mol Δ\DeltaΔ G°f (SbCl3)= -301.25 kJ/mol Δ\DeltaΔ H°f (SbCl5)= -394.34 kJ/mol Δ\DeltaΔ H°f (SbCl3)= -313.80 kJ/mol Will this reaction proceed spontaneously at 298 K and 1 atm pressure?

Choose the substance with the higher entropy per mole at a given temperature: CO2(g)or CO2(aq).

Arrange the following substances in the order of increasing entropy at 25°C. HF(g), NaF(s), SiF4(g), SiH4(g), Al(s) Lowest →\rarr→ highest

Which of the following processes would be accompanied by a decrease in entropy?

Chemistry: the Study of Change

Atoms, Molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metal Chemistry and Coordination Compounds

Organic Chemistry

Synthetic and Natural Organic Polymers

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Using the thermodynamic data provided below, calculate K_a1 for H₂CO₃(aq)at 25°.

Determine $\Delta$ S° for the reaction SO₃(g)+ H₂O(l) $\rarr$ H₂SO₄(l). $Determine \Delta S° for the reaction SO<sub>3</sub>(g)+ H<sub>2</sub>O(l) \rarr H<sub>2</sub>SO<sub>4</sub>(l).$

Calculate the free energy of formation of NaBr(s)given the following information: NaBr(s) $\rarr$ Na(s)+ ¹/₂Br₂(l), $\Delta$ G° = 349 kJ/mol

For any pure substance, if $\Delta$ H_f° = 0 and $\Delta$ G_f° = 0, than S° = 0

What is the free energy change for the reaction SiO₂(s)+ Pb(s) $\rarr$ PbO₂(s)+ Si(s)? $\Delta$ G°_f (PbO₂)= -217 kJ/mol $\Delta$ G°_f (SiO₂)= -856 kJ/mol

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

Choose the substance with the higher entropy per mole at a given temperature: Br₂(l)or Br₂(g).

Which response includes all of the following processes that are accompanied by an increase in entropy? 1)I₂(s) $\rarr$ I₂(g) 2)2I(g) $\rarr$ I₂(g) 3)2NH₃(g) $\rarr$ N₂(g)+ 3H₂(g) 4)Mg²⁺(aq)+ 2OH^-(aq) $\rarr$ Mg(OH)₂(s)

Choose the substance with the higher entropy per mole at a given temperature: 1 mole of N₂(g)in a 22.4 L container or 1 mole of N₂(g)in a 2.24 L container.

Choose the substance with the higher entropy per mole at a given temperature: CO₂(g)or CO₂(aq).

Arrange the following substances in the order of increasing entropy at 25°C. HF(g), NaF(s), SiF₄(g), SiH₄(g), Al(s) Lowest $\rarr$ highest