An important step in the synthesis of nitric acid is the conversion of ammonia to nitric oxide. 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g) Calculate ΔH°rxn for this reaction. ΔH°f [NH3(g)] = -45.9 kJ/mol; ΔH°f [NO(g)] = 90.3 kJ/mol; ΔH°f [H2O(g)] = -241.8 kJ/mol

A) -906.0 kJ B) -197.4 kJ C) -105.6 kJ D) 197.4 kJ E) 906.0 kJ A) -906.0 kJ B) -197.4 kJ C) -105.6 kJ D) 197.4 kJ E) 906.0 kJ A

Your favorite candy bar, Gummy Beakers, contains 1.2 × 106 J of energy while your favorite soft drink, Bolt, contains 6.7 × 105 J. If you eat two packs of Gummy Beakers a day and drink 3 cans of Bolt, what percent of your 2000 Calorie daily food intake is left for broccoli, beans, beef, etc.?

A) 53% B) 47% C) 27% D) 11% E) 0% A) 53% B) 47% C) 27% D) 11% E) 0%

Calculate the enthalpy change for the reaction NO(g) + O(g) → NO2(g) From the following data: NO(g) + O3(g) → NO2(g) + O2(g) ΔH = -198.9 kJ O3(g) → 1.5O2(g) ΔH = -142.3 kJ O2(g) → 2O(g) ΔH = 495.0 kJ

A) -551.6 kJ B) -304.1 kJ C) 190.9 kJ D) 153.8 kJ E) 438.4 kJ A) -551.6 kJ B) -304.1 kJ C) 190.9 kJ D) 153.8 kJ E) 438.4 kJ

Calculate the ΔH°rxn for the following reaction. (ΔH°f [AsH3(g)] = 66.4 kJ/mol; ΔH°f [H3AsO4(aq)] = -904.6 kJ/mol; ΔH°f [H2O(l)] = -285.8 kJ/mol) H3AsO4(aq) + 4H2(g) → AsH3(g) + 4H2O(l)

A) -1981.4 kJ B) -685.2 kJ C) -172.2 kJ D) 172.2 kJ E) 685.2 kJ A) -1981.4 kJ B) -685.2 kJ C) -172.2 kJ D) 172.2 kJ E) 685.2 kJ

Exam 6: Thermochemistry Energy Flow and Chemical Change

If, as a pioneer, you wished to warm your room by taking an object heated on top of a pot-bellied stove to it, which of the following 15-pound objects, each heated to 100°C, would be the best choice? The specific heat capacity (in J/(g·K)) for each substance is given in parentheses. Iron (0.450), copper (0.387), granite (0.79), gold (0.129), water (4.18).

Free

(Multiple Choice)

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Question 1

Correct Answer:

Verified

The only way in which a system can do work on the surroundings is by expansion against the external pressure.

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(True/False)

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Question 2

Correct Answer:

Verified

False

An important step in the synthesis of nitric acid is the conversion of ammonia to nitric oxide. 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g) Calculate ΔH°_rxn for this reaction. ΔH°_f[NH₃(g)] = -45.9 kJ/mol; ΔH°_f [NO(g)] = 90.3 kJ/mol; ΔH°_f [H₂O(g)] = -241.8 kJ/mol

Free

(Multiple Choice)

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Question 3

Correct Answer:

Verified

A system absorbs 21.6 kJ of heat while performing 6.9 kJ of work on the surroundings. If the initial internal energy, E, is 61.2 kJ, what is the final value of E?

(Multiple Choice)

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Question 4

Standard heats (enthalpies) of formation of compounds, ΔH°_f, may be positive or negative.

(True/False)

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Question 5

Which one of the following is not a correct formation reaction? (products are correct)

(Multiple Choice)

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Question 6

Your favorite candy bar, Gummy Beakers, contains 1.2 × 10⁶ J of energy while your favorite soft drink, Bolt, contains 6.7 × 10⁵ J. If you eat two packs of Gummy Beakers a day and drink 3 cans of Bolt, what percent of your 2000 Calorie daily food intake is left for broccoli, beans, beef, etc.?

(Multiple Choice)

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Question 7

Calculate the enthalpy change for the reaction NO(g) + O(g) → NO₂(g) From the following data: NO(g) + O₃(g) → NO₂(g) + O₂(g) ΔH = -198.9 kJ O₃(g) → 1.5O₂(g) ΔH = -142.3 kJ O₂(g) → 2O(g) ΔH = 495.0 kJ

(Multiple Choice)

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Question 8

Which one of the following is a correct formation reaction?

(Multiple Choice)

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Question 9

A system that undergoes an adiabatic change and does work on the surroundings has

(Multiple Choice)

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Question 10

The compound carbon suboxide, C₃O₂, is a gas at room temperature. Use the data supplied to calculate the heat of formation of carbon suboxide. (Data: 2CO(g) + C(s) → C₃O₂(g) ΔH° = 127.3 kJ/mol And: ΔH_f° of CO(g) = -110.5 kJ/mol)

(Multiple Choice)

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Question 11

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/(g·K). Calculate q when 3.65 kg of ethylene glycol is cooled from 132°C to 85°C.

(Multiple Choice)

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Question 12

Which of the following is not a state function?

(Multiple Choice)

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Question 13

In an endothermic reaction, in going from the reactants to the products at the same temperature, the value of q is negative.

(True/False)

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Question 14

Combustion of a hydrocarbon will release more energy than combustion of an equal mass of carbohydrate because

(Multiple Choice)

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Question 15

In a phase change of water between the liquid and the gas phases, 770.1 kJ of energy was released by the system. What was the product, and how much of it was formed in the phase change? (Data: H₂O(l) → H₂O(g) ΔH = 44.01 kJ/mol.)

(Multiple Choice)

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Question 16

Calculate the ΔH°_rxn for the following reaction. (ΔH°_f[AsH₃(g)] = 66.4 kJ/mol; ΔH°_f[H₃AsO₄(aq)] = -904.6 kJ/mol; ΔH°_f[H₂O(l)] = -285.8 kJ/mol) H₃AsO₄(aq) + 4H₂(g) → AsH₃(g) + 4H₂O(l)

(Multiple Choice)

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Question 17

A system expands from a volume of 1.00 L to 2.00 L against a constant external pressure of 1.00 atm. The work (w) done by the system, in J, is

(Multiple Choice)

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Question 18

A backpacker collects snow at 0°C, and places it in a cooking pot on a camp stove. It takes 643 kJ of heat energy to melt the snow and bring the water to boiling. Assuming no heat loss, and neglecting the specific heat capacity of the pot, calculate the mass of snow that the backpacker collected. (Data: specific heat capacity of liquid water, c = 4.18 J/g·K; and: H₂O(s) → H₂O(l) ΔH = ΔH_fusion = 6.02 kJ/mol)

(Multiple Choice)

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Question 19

A Snickers^® candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?

(Multiple Choice)

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Question 20

Showing 1 - 20 of 72

Exam 6: Thermochemistry Energy Flow and Chemical Change

The only way in which a system can do work on the surroundings is by expansion against the external pressure.

An important step in the synthesis of nitric acid is the conversion of ammonia to nitric oxide. 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g) Calculate ΔH°rxn for this reaction. ΔH°f [NH3(g)] = -45.9 kJ/mol; ΔH°f [NO(g)] = 90.3 kJ/mol; ΔH°f [H2O(g)] = -241.8 kJ/mol

A system absorbs 21.6 kJ of heat while performing 6.9 kJ of work on the surroundings. If the initial internal energy, E, is 61.2 kJ, what is the final value of E?

Standard heats (enthalpies) of formation of compounds, ΔH°f, may be positive or negative.

Which one of the following is not a correct formation reaction? (products are correct)

Your favorite candy bar, Gummy Beakers, contains 1.2 × 106 J of energy while your favorite soft drink, Bolt, contains 6.7 × 105 J. If you eat two packs of Gummy Beakers a day and drink 3 cans of Bolt, what percent of your 2000 Calorie daily food intake is left for broccoli, beans, beef, etc.?

Calculate the enthalpy change for the reaction NO(g) + O(g) → NO2(g) From the following data: NO(g) + O3(g) → NO2(g) + O2(g) ΔH = -198.9 kJ O3(g) → 1.5O2(g) ΔH = -142.3 kJ O2(g) → 2O(g) ΔH = 495.0 kJ

Which one of the following is a correct formation reaction?

A system that undergoes an adiabatic change and does work on the surroundings has

The compound carbon suboxide, C3O2, is a gas at room temperature. Use the data supplied to calculate the heat of formation of carbon suboxide. (Data: 2CO(g) + C(s) → C3O2(g) ΔH° = 127.3 kJ/mol And: ΔHf° of CO(g) = -110.5 kJ/mol)

Ethylene glycol, used as a coolant in automotive engines, has a specific heat capacity of 2.42 J/(g·K). Calculate q when 3.65 kg of ethylene glycol is cooled from 132°C to 85°C.

Which of the following is not a state function?

In an endothermic reaction, in going from the reactants to the products at the same temperature, the value of q is negative.

Combustion of a hydrocarbon will release more energy than combustion of an equal mass of carbohydrate because

In a phase change of water between the liquid and the gas phases, 770.1 kJ of energy was released by the system. What was the product, and how much of it was formed in the phase change? (Data: H2O(l) → H2O(g) ΔH = 44.01 kJ/mol.)

Calculate the ΔH°rxn for the following reaction. (ΔH°f [AsH3(g)] = 66.4 kJ/mol; ΔH°f [H3AsO4(aq)] = -904.6 kJ/mol; ΔH°f [H2O(l)] = -285.8 kJ/mol) H3AsO4(aq) + 4H2(g) → AsH3(g) + 4H2O(l)

A system expands from a volume of 1.00 L to 2.00 L against a constant external pressure of 1.00 atm. The work (w) done by the system, in J, is

A Snickers® candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?

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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An important step in the synthesis of nitric acid is the conversion of ammonia to nitric oxide. 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g) Calculate ΔH°_rxn for this reaction. ΔH°_f[NH₃(g)] = -45.9 kJ/mol; ΔH°_f [NO(g)] = 90.3 kJ/mol; ΔH°_f [H₂O(g)] = -241.8 kJ/mol

Standard heats (enthalpies) of formation of compounds, ΔH°_f, may be positive or negative.

Your favorite candy bar, Gummy Beakers, contains 1.2 × 10⁶ J of energy while your favorite soft drink, Bolt, contains 6.7 × 10⁵ J. If you eat two packs of Gummy Beakers a day and drink 3 cans of Bolt, what percent of your 2000 Calorie daily food intake is left for broccoli, beans, beef, etc.?

Calculate the enthalpy change for the reaction NO(g) + O(g) → NO₂(g) From the following data: NO(g) + O₃(g) → NO₂(g) + O₂(g) ΔH = -198.9 kJ O₃(g) → 1.5O₂(g) ΔH = -142.3 kJ O₂(g) → 2O(g) ΔH = 495.0 kJ

The compound carbon suboxide, C₃O₂, is a gas at room temperature. Use the data supplied to calculate the heat of formation of carbon suboxide. (Data: 2CO(g) + C(s) → C₃O₂(g) ΔH° = 127.3 kJ/mol And: ΔH_f° of CO(g) = -110.5 kJ/mol)

In a phase change of water between the liquid and the gas phases, 770.1 kJ of energy was released by the system. What was the product, and how much of it was formed in the phase change? (Data: H₂O(l) → H₂O(g) ΔH = 44.01 kJ/mol.)

Calculate the ΔH°_rxn for the following reaction. (ΔH°_f[AsH₃(g)] = 66.4 kJ/mol; ΔH°_f[H₃AsO₄(aq)] = -904.6 kJ/mol; ΔH°_f[H₂O(l)] = -285.8 kJ/mol) H₃AsO₄(aq) + 4H₂(g) → AsH₃(g) + 4H₂O(l)

A Snickers^® candy bar contains 280 Calories, of which the fat content accounts for 120 Calories. What is the energy of the fat content, in kJ?