Use Hess's Law to calculate the enthalpy change for the reaction WO3(s) + 3H2(g) → W(s) + 3H2O(g) From the following data: 2W(s) + 3O2(g) → 2WO3(s) ΔH = -1685.4 kJ 2H2(g) + O2(g) → 2H2O(g) ΔH = -477.84 kJ

A) 125.9 kJ B) 252.9 kJ C) 364.9 kJ D) 1207.6 kJ E) None of these choices are correct. A) 125.9 kJ B) 252.9 kJ C) 364.9 kJ D) 1207.6 kJ E) None of these choices are correct.

Exam 6: Thermochemistry Energy Flow and Chemical Change

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Use Hess's Law to calculate the enthalpy change for the reaction WO₃(s) + 3H₂(g) → W(s) + 3H₂O(g) From the following data: 2W(s) + 3O₂(g) → 2WO₃(s) ΔH = -1685.4 kJ 2H₂(g) + O₂(g) → 2H₂O(g) ΔH = -477.84 kJ

(Multiple Choice)

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Question 61

Ethanol, C₂H₅OH, is being promoted as a clean fuel and is used as an additive in many gasoline mixtures. Calculate the ΔH°_rxn for the combustion of ethanol. (ΔH°_f [C₂H₅OH(l)] = -277.7 kJ/mol; ΔH°_f [CO₂(g)] = -393.5 kJ/mol; ΔH°_f [H2O(g)] = -241.8 kJ/mol)

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Question 62

For all processes, both q and ΔE will have the same sign.

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Question 63

In which one of the following processes is ΔH = ΔE?

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Question 64

Which one of the following relationships is always correct?

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Question 65

A system that does no work but that transfers heat to the surroundings has

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Question 66

Natural gas, or methane, is an important fuel. Combustion of one mole of methane releases 802.3 kilojoules of energy. How much energy does that represent in kilocalories?

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Question 67

The Starship Enterprise is caught in a time warp and Spock is forced to use the primitive techniques of the 20th century to determine the specific heat capacity of an unknown mineral. The 307-g sample was heated to 98.7°C and placed into a calorimeter containing 72.4 g of water at 23.6°C. The heat capacity of the calorimeter was 15.7 J/K. The final temperature in the calorimeter was 32.4°C. What is the specific heat capacity of the mineral?

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Question 68

In a reaction with high energy reactants and low energy products, q is negative.

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Question 69

In which one of the following reactions would you expect ΔH to be substantially greater than ΔE (i.e., ΔH > ΔE)?

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Question 70

When Karl Kaveman adds chilled grog to his new granite mug, he removes 10.9 kJ of energy from the mug. If it has a mass of 625 g and was at 25°C, what is its new temperature? Specific heat capacity of granite = 0.79 J/(g·K)

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Question 71

For which one of the following reactions will ΔH be approximately (or exactly) equal to ΔE?

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Question 72

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Use Hess's Law to calculate the enthalpy change for the reaction WO₃(s) + 3H₂(g) → W(s) + 3H₂O(g) From the following data: 2W(s) + 3O₂(g) → 2WO₃(s) ΔH = -1685.4 kJ 2H₂(g) + O₂(g) → 2H₂O(g) ΔH = -477.84 kJ

Ethanol, C₂H₅OH, is being promoted as a clean fuel and is used as an additive in many gasoline mixtures. Calculate the ΔH°_rxn for the combustion of ethanol. (ΔH°_f [C₂H₅OH(l)] = -277.7 kJ/mol; ΔH°_f [CO₂(g)] = -393.5 kJ/mol; ΔH°_f [H2O(g)] = -241.8 kJ/mol)

For all processes, both q and ΔE will have the same sign.

In which one of the following processes is ΔH = ΔE?

Which one of the following relationships is always correct?

A system that does no work but that transfers heat to the surroundings has

Natural gas, or methane, is an important fuel. Combustion of one mole of methane releases 802.3 kilojoules of energy. How much energy does that represent in kilocalories?

In a reaction with high energy reactants and low energy products, q is negative.

In which one of the following reactions would you expect ΔH to be substantially greater than ΔE (i.e., ΔH > ΔE)?

When Karl Kaveman adds chilled grog to his new granite mug, he removes 10.9 kJ of energy from the mug. If it has a mass of 625 g and was at 25°C, what is its new temperature? Specific heat capacity of granite = 0.79 J/(g·K)

For which one of the following reactions will ΔH be approximately (or exactly) equal to ΔE?

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

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

Thermodynamics Entropy, Free Energy, and Reaction Direction

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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Exam 6: Thermochemistry Energy Flow and Chemical Change

Use Hess's Law to calculate the enthalpy change for the reaction WO3(s) + 3H2(g) → W(s) + 3H2O(g) From the following data: 2W(s) + 3O2(g) → 2WO3(s) ΔH = -1685.4 kJ 2H2(g) + O2(g) → 2H2O(g) ΔH = -477.84 kJ

Ethanol, C2H5OH, is being promoted as a clean fuel and is used as an additive in many gasoline mixtures. Calculate the ΔH°rxn for the combustion of ethanol. (ΔH°f [C2H5OH(l)] = -277.7 kJ/mol; ΔH°f [CO2(g)] = -393.5 kJ/mol; ΔH°f [H2O(g)] = -241.8 kJ/mol)

For all processes, both q and ΔE will have the same sign.

In which one of the following processes is ΔH = ΔE?

Which one of the following relationships is always correct?

A system that does no work but that transfers heat to the surroundings has

Natural gas, or methane, is an important fuel. Combustion of one mole of methane releases 802.3 kilojoules of energy. How much energy does that represent in kilocalories?

In a reaction with high energy reactants and low energy products, q is negative.

In which one of the following reactions would you expect ΔH to be substantially greater than ΔE (i.e., ΔH > ΔE)?

When Karl Kaveman adds chilled grog to his new granite mug, he removes 10.9 kJ of energy from the mug. If it has a mass of 625 g and was at 25°C, what is its new temperature? Specific heat capacity of granite = 0.79 J/(g·K)

For which one of the following reactions will ΔH be approximately (or exactly) equal to ΔE?

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

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

Thermodynamics Entropy, Free Energy, and Reaction Direction

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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Use Hess's Law to calculate the enthalpy change for the reaction WO₃(s) + 3H₂(g) → W(s) + 3H₂O(g) From the following data: 2W(s) + 3O₂(g) → 2WO₃(s) ΔH = -1685.4 kJ 2H₂(g) + O₂(g) → 2H₂O(g) ΔH = -477.84 kJ

Ethanol, C₂H₅OH, is being promoted as a clean fuel and is used as an additive in many gasoline mixtures. Calculate the ΔH°_rxn for the combustion of ethanol. (ΔH°_f [C₂H₅OH(l)] = -277.7 kJ/mol; ΔH°_f [CO₂(g)] = -393.5 kJ/mol; ΔH°_f [H2O(g)] = -241.8 kJ/mol)