Question 1

Which of the following statements is TRUE?

Accepted Answer

A) Entropy is not a state function. 
B) Endothermic processes decrease the entropy of the surroundings, at constant T and P. 
C) Endothermic processes are never spontaneous. 
D) Exothermic processes are always spontaneous. 
E) Entropy of the universe is a constant value. 
A) Entropy is not a state function. 
B) Endothermic processes decrease the entropy of the surroundings, at constant T and P. 
C) Endothermic processes are never spontaneous. 
D) Exothermic processes are always spontaneous. 
E) Entropy of the universe is a constant value.

Question 2

What is the name of the reaction that achieves the theoretical limits with respect to the change in Gibbs energy in thermodynamics?

Accepted Answer

A) reversible reaction 
B) forward reaction 
C) reverse reaction 
D) equilibrium reaction 
E) irreversible reaction 
A) reversible reaction 
B) forward reaction 
C) reverse reaction 
D) equilibrium reaction 
E) irreversible reaction

Question 3

Estimate ΔrG° for the following reaction at 775 K. 2Hg(g)+ O2(g)→ 2HgO(s) ΔrH°= -304.2 kJ mol-1; ΔrS°= -414.2 J K-1 mol-1

Accepted Answer

A) -625 kJ mol-1 
B) -181 kJ mol-1 
C) +17 kJ mol-1 
D) +321 kJ mol-1 
E) -110 kJ mol-1 
A) -625 kJ mol-1 
B) -181 kJ mol-1 
C) +17 kJ mol-1 
D) +321 kJ mol-1 
E) -110 kJ mol-1

Question 4

Above what temperature does the following reaction become nonspontaneous? FeO(s)+ CO(g)→ CO2(g)+ Fe(s)ΔrH = -11.0 kJ; ΔrS = -17.4 J K-1 mol-1

Accepted Answer

A) 632 K 
B) 298 K 
C) 191 K 
D) 6.32 × 103 K 
E) 0 K 
A) 632 K 
B) 298 K 
C) 191 K 
D) 6.32 × 103 K 
E) 0 K

Question 5

Identify the statement that is TRUE.

Accepted Answer

A) The entropy of a gas is lower than the entropy of a liquid. 
B) Entropy generally decreases with increasing molecular complexity. 
C) Free atoms have lower entropy than molecules. 
D) Entropy decreases with dissolution. 
E) For noble gases, entropy decreases with increase in atomic size. 
A) The entropy of a gas is lower than the entropy of a liquid. 
B) Entropy generally decreases with increasing molecular complexity. 
C) Free atoms have lower entropy than molecules. 
D) Entropy decreases with dissolution. 
E) For noble gases, entropy decreases with increase in atomic size.

Question 6

Place the following in order of decreasing standard molar entropy. N2O4(g)NO(g)NO2(g)

Accepted Answer

A) N2O4 > NO2 > NO 
B) NO > NO2 > N2O4 
C) N2O4 > NO > NO2 
D) NO > N2O4 > NO2 
E) NO2 > NO > N2O4 
A) N2O4 > NO2 > NO 
B) NO > NO2 > N2O4 
C) N2O4 > NO > NO2 
D) NO > N2O4 > NO2 
E) NO2 > NO > N2O4

Question 7

Which of the following reactions will have the largest equilibrium constant (K)at 298 K?

Accepted Answer

A) CaCO3(s)→ CaO(s)+ CO2(g)ΔrG° =+131.1 kJ mol-1 
B) 2 Hg(g)+ O2(g)→ 2HgO(s) ΔrG° = -180.8 kJ mol-1 
C) 3O2(g)→ 2O3(g) ΔrG° = +326 kJ mol-1 
D) Fe2O3(s)+ 3CO(g)→ 2Fe(s)+ 3CO2(g)ΔrG° = -28.0 kJ mol-1 
A) CaCO3(s)→ CaO(s)+ CO2(g)ΔrG° =+131.1 kJ mol-1 
B) 2 Hg(g)+ O2(g)→ 2HgO(s) ΔrG° = -180.8 kJ mol-1 
C) 3O2(g)→ 2O3(g) ΔrG° = +326 kJ mol-1 
D) Fe2O3(s)+ 3CO(g)→ 2Fe(s)+ 3CO2(g)ΔrG° = -28.0 kJ mol-1

Question 8

Match the following.

-Q < K

Accepted Answer

A) K = 0 
B) ?rG > 0 
C) ($\Delta$rG rG rG° 
E) equilibrium
F)?rG > ?rG°
G)standard state 
A) K = 0 
B) ?rG > 0 
C) ($\Delta$rG rG rG° 
E) equilibrium
F)?rG > ?rG°
G)standard state

Question 9

Determine the equilibrium constant for the following reaction at 549 K: CH2O(g)+ 2H2(g)→ CH4(g)+ H2O(g) ΔrH° = -94.9 kJ mol-1; ΔrS°= -224.2 J K-1 mol-1

Accepted Answer

A) 481 
B) 1.07 × 109 
C) 2.08 × 10-3 
D) 9.35 × 10-10 
E) 1.94 × 10-12 
A) 481 
B) 1.07 × 109 
C) 2.08 × 10-3 
D) 9.35 × 10-10 
E) 1.94 × 10-12

Question 10

Which one of the following has the highest standard molar entropy, S°, at 25 °C?

Accepted Answer

A) H2(g) 
B) F2(g) 
C) O2(g) 
D) N2(g) 
E) Cl2(g) 
A) H2(g) 
B) F2(g) 
C) O2(g) 
D) N2(g) 
E) Cl2(g)

Question 11

Given the following equation, N2O(g)+ NO2(g)→ 3NO(g)ΔrG° = -23.0 kJ mol-1
Calculate ΔrGo for the following reaction:
3NO(g)→ N2O(g)+ NO2(g)

Accepted Answer

A) -23.0 kJ mol-1 
B) 69.0 kJ mol-1 
C) -69.0 kJ mol-1 
D) -7.67 kJ mol-1 
E) 23.0 kJ mol-1 
A) -23.0 kJ mol-1 
B) 69.0 kJ mol-1 
C) -69.0 kJ mol-1 
D) -7.67 kJ mol-1 
E) 23.0 kJ mol-1

Question 12

What is the name of the reaction that does NOT achieve the theoretical limits with respect to the change in Gibbs energy in thermodynamics?

Accepted Answer

A) reversible reaction 
B) forward reaction 
C) reverse reaction 
D) equilibrium reaction 
E) irreversible reaction 
A) reversible reaction 
B) forward reaction 
C) reverse reaction 
D) equilibrium reaction 
E) irreversible reaction

Question 13

Identify the compound with the lowest standard Gibbs energy of formation.

Accepted Answer

A) NaCl(s) 
B) N2(g) 
C) NO(g) 
D) O3(g) 
E) Cl2(g) 
A) NaCl(s) 
B) N2(g) 
C) NO(g) 
D) O3(g) 
E) Cl2(g)

Question 14

Calculate ΔrG° at 298 K using the following information: 2HNO3(aq)+ NO(g)→ 3NO2(g)+ H2O(l)ΔrG° = ?
ΔfG° (kJ mol-1)-110.9 87.6 51.3 -237.1

Accepted Answer

A) -162.5 kJ mol-1 
B) +51.0 kJ mol-1 
C) -54.5 kJ mol-1 
D) +171.1 kJ mol-1 
E) -87.6 kJ mol-1 
A) -162.5 kJ mol-1 
B) +51.0 kJ mol-1 
C) -54.5 kJ mol-1 
D) +171.1 kJ mol-1 
E) -87.6 kJ mol-1

Question 15

Place the following in order of increasing molar entropy at 298 K. NO CO SO

Accepted Answer

A) NO < CO < SO 
B) SO < CO < NO 
C) SO < NO < CO 
D) CO < SO < NO 
E) CO < NO < SO 
A) NO < CO < SO 
B) SO < CO < NO 
C) SO < NO < CO 
D) CO < SO < NO 
E) CO < NO < SO

Question 16

Give the standard states for a gas, liquid, solid, and solution.

Accepted Answer

For a gas, 1 atm; for a liquid

Question 17

Which of the following processes shows a decrease in entropy of the system?

Accepted Answer

A) 2NO(g)+ O2(g)→ 2NO2(g) 
B) COCl2(g)→ CO(g)+ Cl2(g) 
C) CH3OH(l)→ CO(g)+ 2H2(g) 
D) NaClO3(s)→ Na+(aq)+ ClO3-(aq) 
E) H2(g)+ Cl2(g)→ 2HCl(g) 
A) 2NO(g)+ O2(g)→ 2NO2(g) 
B) COCl2(g)→ CO(g)+ Cl2(g) 
C) CH3OH(l)→ CO(g)+ 2H2(g) 
D) NaClO3(s)→ Na+(aq)+ ClO3-(aq) 
E) H2(g)+ Cl2(g)→ 2HCl(g)

Question 18

Which of the following is TRUE regarding allotropes?

Accepted Answer

A) Allotropes are different forms of the same element, but they have identical standard molar enthalpies. 
B) Allotropes are different forms of the same element and have different standard molar enthalpies. 
C) Allotropes are composed of different isotopes of the same element and have different standard molar enthalpies. 
D) Allotropes are composed of different isotopes of the same element and identical standard molar enthalpies. 
E) Allotropes are different elements with the same structure and have different standard molar enthalpies. 
A) Allotropes are different forms of the same element, but they have identical standard molar enthalpies. 
B) Allotropes are different forms of the same element and have different standard molar enthalpies. 
C) Allotropes are composed of different isotopes of the same element and have different standard molar enthalpies. 
D) Allotropes are composed of different isotopes of the same element and identical standard molar enthalpies. 
E) Allotropes are different elements with the same structure and have different standard molar enthalpies.

Question 19

Consider a reaction that has a negative ΔrH and a negative ΔrS. Which of the following statements is TRUE?

Accepted Answer

A) This reaction will be spontaneous only at high temperatures. 
B) This reaction will be spontaneous at all temperatures. 
C) This reaction will be nonspontaneous at all temperatures. 
D) This reaction will be nonspontaneous only at high temperatures. 
E) This reaction will be spontaneous only at absolute zero (0 Kelvin). 
A) This reaction will be spontaneous only at high temperatures. 
B) This reaction will be spontaneous at all temperatures. 
C) This reaction will be nonspontaneous at all temperatures. 
D) This reaction will be nonspontaneous only at high temperatures. 
E) This reaction will be spontaneous only at absolute zero (0 Kelvin).

Question 20

Why is heating your home with gas more efficient than heating it with electricity?

Accepted Answer

Heating with gas only requires a one-ste

Exam 17: Gibbs Energy and Thermodynamics

Which of the following statements is TRUE?

What is the name of the reaction that achieves the theoretical limits with respect to the change in Gibbs energy in thermodynamics?

Estimate ΔrG° for the following reaction at 775 K. 2Hg(g)+ O2(g)→ 2HgO(s) ΔrH°= -304.2 kJ mol-1; ΔrS°= -414.2 J K-1 mol-1

Above what temperature does the following reaction become nonspontaneous? FeO(s)+ CO(g)→ CO2(g)+ Fe(s)ΔrH = -11.0 kJ; ΔrS = -17.4 J K-1 mol-1

Identify the statement that is TRUE.

Place the following in order of decreasing standard molar entropy. N2O4(g)NO(g)NO2(g)

Which of the following reactions will have the largest equilibrium constant (K)at 298 K?

Match the following. -Q < K

Determine the equilibrium constant for the following reaction at 549 K: CH2O(g)+ 2H2(g)→ CH4(g)+ H2O(g) ΔrH° = -94.9 kJ mol-1; ΔrS°= -224.2 J K-1 mol-1

Which one of the following has the highest standard molar entropy, S°, at 25 °C?

Given the following equation, N2O(g)+ NO2(g)→ 3NO(g)ΔrG° = -23.0 kJ mol-1 Calculate ΔrGo for the following reaction: 3NO(g)→ N2O(g)+ NO2(g)

What is the name of the reaction that does NOT achieve the theoretical limits with respect to the change in Gibbs energy in thermodynamics?

Identify the compound with the lowest standard Gibbs energy of formation.

Calculate ΔrG° at 298 K using the following information: 2HNO3(aq)+ NO(g)→ 3NO2(g)+ H2O(l)ΔrG° = ? ΔfG° (kJ mol-1)-110.9 87.6 51.3 -237.1

Place the following in order of increasing molar entropy at 298 K. NO CO SO

Give the standard states for a gas, liquid, solid, and solution.

Which of the following processes shows a decrease in entropy of the system?

Which of the following is TRUE regarding allotropes?

Consider a reaction that has a negative ΔrH and a negative ΔrS. Which of the following statements is TRUE?

Why is heating your home with gas more efficient than heating it with electricity?

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Molecules, Compounds, and Nomenclature

Chemical Reactions and Stoichiometry

Gases

Thermochemistry

The Quantum-Mechanical Model of the Atom

Periodic Properties of the Elements

Chemical Bonding I: Lewis Theory

Chemical Bonding Ii: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory

Liquids, Solids, and Intermolecular Forces

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Organic Chemistry I: Structures

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Estimate Δ_rG° for the following reaction at 775 K. 2Hg(g)+ O₂(g)→ 2HgO(s) Δ_rH°= -304.2 kJ mol^-1; Δ_rS°= -414.2 J K^-1 mol^-1

Above what temperature does the following reaction become nonspontaneous? FeO(s)+ CO(g)→ CO₂(g)+ Fe(s)Δ_rH = -11.0 kJ; Δ_rS = -17.4 J K^-1 mol^-1

Place the following in order of decreasing standard molar entropy. N₂O₄(g)NO(g)NO₂(g)

Determine the equilibrium constant for the following reaction at 549 K: CH₂O(g)+ 2H₂(g)→ CH₄(g)+ H₂O(g) Δ_rH° = -94.9 kJ mol^-1; Δ_rS°= -224.2 J K^-1 mol^-1

Given the following equation, N₂O(g)+ NO₂(g)→ 3NO(g)Δ_rG°= -23.0 kJ mol^-1 Calculate Δ_rG^o for the following reaction: 3NO(g)→ N₂O(g)+ NO₂(g)

Calculate Δ_rG° at 298 K using the following information: 2HNO₃(aq)+ NO(g)→ 3NO₂(g)+ H₂O(l)Δ_rG°= ? Δ_fG° (kJ mol^-1)-110.9 87.6 51.3 -237.1

Consider a reaction that has a negative Δ_rH and a negative Δ_rS. Which of the following statements is TRUE?