Calculate ΔG° for the reaction of ammonia with fluorine. 2NH3(g) + 5F2(g) → N2F4(g) + 6HF(g) Substance: NH3(g) F2(g) N2F4(g) HF(g) ΔG°f (kJ/mol): -16.4 0 9.9 -275.4

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

Which of the following is true for pure oxygen gas, O2(g) at 25°C?

A) ΔH°f > 0 B) ΔH°f f > 0 D) ΔG°f 0 A) ΔH°f > 0 B) ΔH°f f > 0 D) ΔG°f 0

Calculate ΔS° for the combustion of propane. C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g) Substance: C3H8(g) O2(g) CO2(g) H2O(g) S°(J/K·mol): 269.9 205.138 213.74 18.825

A) -100.9 J/K B) -72.5 J/K C) 72.5 J/K D) 100.9 J/K E) 877.5 J/K A) -100.9 J/K B) -72.5 J/K C) 72.5 J/K D) 100.9 J/K E) 877.5 J/K

The formation constant for the reaction Ag+(aq) + 2NH3(aq) Ag(NH3)2+(aq) Is Kf = 1.7 × 107 at 25°C. What is ΔG° at this temperature?

A) -1.5 kJ B) -3.5 kJ C) -18 kJ D) -23 kJ E) -41 kJ A) -1.5 kJ B) -3.5 kJ C) -18 kJ D) -23 kJ E) -41 kJ

Calculate ΔS° for the reaction 2Cl2(g) + SO2(g) → SOCl2(g) + Cl2O(g) Substance: Cl2(g) SO2(g) SOCl2(g) Cl2O(g) S°(J/K·mol): 223.0 248.1 309.77 266.1

A) -118.2 J/K B) -104.8 J/K C) 104.8 J/K D) 118.2 J/K E) 1270.0 J/K A) -118.2 J/K B) -104.8 J/K C) 104.8 J/K D) 118.2 J/K E) 1270.0 J/K

Calculate ΔS° for the reaction 4Cr(s) + 3O2(g) → 2Cr2O3(s) Substance: Cr(s) O2(g) Cr2O3(s) S°(J/K·mol): 23.77 205.138 81.2

A) -548.1 J/K B) -147.7 J/K C) 147.7 J/K D) 310.1 J/K E) 548.1 J/K A) -548.1 J/K B) -147.7 J/K C) 147.7 J/K D) 310.1 J/K E) 548.1 J/K

Exam 20: Thermodynamics Entropy, Free Energy, and Reaction Direction

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A reaction is proceeding toward equilibrium. At a certain stage, the concentrations of reactants and products are such that ΔG = ΔG°. What conclusion can reasonably be drawn about the reaction at this time?

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Question 61

Calculate ΔG° for the reaction of ammonia with fluorine. 2NH₃(g) + 5F₂(g) → N₂F₄(g) + 6HF(g) Substance: NH₃(g) F₂(g) N₂F₄(g) HF(g) ΔG°_f (kJ/mol): -16.4 0 9.9 -275.4

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Question 62

Given: H₂O(l) → H₂O(g) ΔH° = 40.7 kJ at 373K What is the entropy change in the system (ΔS) when one mole of water vaporizes at 100°C and a pressure of one atmosphere?

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Question 63

In which one of the following pairs will the first system have a higher entropy than the second? Assume P and T are the same for each pair, unless stated otherwise.

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Question 64

Which relationship or statement best describes ΔS° for the following reaction? O₃(g) + NO(g) → O₂(g) + NO₂(g)

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Question 65

Which of the following is true for pure oxygen gas, O₂(g) at 25°C?

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Question 66

Calculate ΔS° for the combustion of propane. C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(g) Substance: C₃H₈(g) O₂(g) CO₂(g) H₂O(g) S°(J/K·mol): 269.9 205.138 213.74 18.825

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Question 67

"A diamond is forever" is one of the most successful advertising slogans of all time. But is it true? For the reaction shown below, calculate the standard free energy change at 298K and determine whether or not a diamond is "forever". C(diamond) → C(graphite) Data: ΔH_f°(diamond) = 1.895 kJ/mol; S°(diamond) = 2.337 J mol^-1K^-1; S°(graphite) = 5.740 J mol^-1K^-1.

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Question 68

What is the free energy change, ΔG°, for the equilibrium between hydrogen iodide, hydrogen, and iodine at 453°C? K_c = 0.020 2HI(g) H₂(g) + I₂(g)

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Question 69

For a process with ΔS < 0, which one of the following statements is correct?

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Question 70

For a given reaction, a change in the pressure may result in a change in the sign of ΔG.

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Question 71

The formation constant for the reaction Ag⁺(aq) + 2NH₃(aq) Ag(NH₃)²⁺(aq) Is K_f = 1.7 × 10⁷ at 25°C. What is ΔG° at this temperature?

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Question 72

The second law of thermodynamics tells us that

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Question 73

Calculate ΔS° for the reaction 2Cl₂(g) + SO₂(g) → SOCl₂(g) + Cl₂O(g) Substance: Cl₂(g) SO₂(g) SOCl₂(g) Cl₂O(g) S°(J/K·mol): 223.0 248.1 309.77 266.1

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Question 74

In some spontaneous processes, the entropy of the surroundings decreases.

(True/False)

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Question 75

In a spontaneous process, the entropy of the system always increases.

(True/False)

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Question 76

For a reaction at equilibrium, ΔS_univ = 0.

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Question 77

Consider the figure that shows ΔG° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that

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Question 78

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 5K temperature intervals would there be the greatest increase in the entropy of the sample?

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Question 79

Calculate ΔS° for the reaction 4Cr(s) + 3O₂(g) → 2Cr₂O₃(s) Substance: Cr(s) O₂(g) Cr₂O₃(s) S°(J/K·mol): 23.77 205.138 81.2

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Question 80

Showing 61 - 80 of 84

Exam 20: Thermodynamics Entropy, Free Energy, and Reaction Direction

A reaction is proceeding toward equilibrium. At a certain stage, the concentrations of reactants and products are such that ΔG = ΔG°. What conclusion can reasonably be drawn about the reaction at this time?

Calculate ΔG° for the reaction of ammonia with fluorine. 2NH3(g) + 5F2(g) → N2F4(g) + 6HF(g) Substance: NH3(g) F2(g) N2F4(g) HF(g) ΔG°f (kJ/mol): -16.4 0 9.9 -275.4

Given: H2O(l) → H2O(g) ΔH° = 40.7 kJ at 373K What is the entropy change in the system (ΔS) when one mole of water vaporizes at 100°C and a pressure of one atmosphere?

In which one of the following pairs will the first system have a higher entropy than the second? Assume P and T are the same for each pair, unless stated otherwise.

Which relationship or statement best describes ΔS° for the following reaction? O3(g) + NO(g) → O2(g) + NO2(g)

Which of the following is true for pure oxygen gas, O2(g) at 25°C?

Calculate ΔS° for the combustion of propane. C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g) Substance: C3H8(g) O2(g) CO2(g) H2O(g) S°(J/K·mol): 269.9 205.138 213.74 18.825

What is the free energy change, ΔG°, for the equilibrium between hydrogen iodide, hydrogen, and iodine at 453°C? Kc = 0.020 2HI(g) H2(g) + I2(g)

For a process with ΔS < 0, which one of the following statements is correct?

For a given reaction, a change in the pressure may result in a change in the sign of ΔG.

The formation constant for the reaction Ag+(aq) + 2NH3(aq) Ag(NH3)2+(aq) Is Kf = 1.7 × 107 at 25°C. What is ΔG° at this temperature?

The second law of thermodynamics tells us that

Calculate ΔS° for the reaction 2Cl2(g) + SO2(g) → SOCl2(g) + Cl2O(g) Substance: Cl2(g) SO2(g) SOCl2(g) Cl2O(g) S°(J/K·mol): 223.0 248.1 309.77 266.1

In some spontaneous processes, the entropy of the surroundings decreases.

In a spontaneous process, the entropy of the system always increases.

For a reaction at equilibrium, ΔSuniv = 0.

Consider the figure that shows ΔG° for a chemical process plotted against absolute temperature. From this plot, it is reasonable to conclude that

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 5K temperature intervals would there be the greatest increase in the entropy of the sample?

Calculate ΔS° for the reaction 4Cr(s) + 3O2(g) → 2Cr2O3(s) Substance: Cr(s) O2(g) Cr2O3(s) S°(J/K·mol): 23.77 205.138 81.2

Keys to Studying Chemistry Definitions, Units, and Problem Solving

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

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

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Calculate ΔG° for the reaction of ammonia with fluorine. 2NH₃(g) + 5F₂(g) → N₂F₄(g) + 6HF(g) Substance: NH₃(g) F₂(g) N₂F₄(g) HF(g) ΔG°_f (kJ/mol): -16.4 0 9.9 -275.4

Given: H₂O(l) → H₂O(g) ΔH° = 40.7 kJ at 373K What is the entropy change in the system (ΔS) when one mole of water vaporizes at 100°C and a pressure of one atmosphere?

Which relationship or statement best describes ΔS° for the following reaction? O₃(g) + NO(g) → O₂(g) + NO₂(g)

Which of the following is true for pure oxygen gas, O₂(g) at 25°C?

Calculate ΔS° for the combustion of propane. C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(g) Substance: C₃H₈(g) O₂(g) CO₂(g) H₂O(g) S°(J/K·mol): 269.9 205.138 213.74 18.825

What is the free energy change, ΔG°, for the equilibrium between hydrogen iodide, hydrogen, and iodine at 453°C? K_c = 0.020 2HI(g) H₂(g) + I₂(g)

The formation constant for the reaction Ag⁺(aq) + 2NH₃(aq) Ag(NH₃)²⁺(aq) Is K_f = 1.7 × 10⁷ at 25°C. What is ΔG° at this temperature?

Calculate ΔS° for the reaction 2Cl₂(g) + SO₂(g) → SOCl₂(g) + Cl₂O(g) Substance: Cl₂(g) SO₂(g) SOCl₂(g) Cl₂O(g) S°(J/K·mol): 223.0 248.1 309.77 266.1

For a reaction at equilibrium, ΔS_univ = 0.

Calculate ΔS° for the reaction 4Cr(s) + 3O₂(g) → 2Cr₂O₃(s) Substance: Cr(s) O₂(g) Cr₂O₃(s) S°(J/K·mol): 23.77 205.138 81.2