Question 1

The following diagrams illustrate the flow of energy (q) and work (w) in different processes. Which one is definitely an exothermic process?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)    C

Question 2

Thermochemistry is the study of how ________ is produced and consumed during chemical reactions.

Accepted Answer

A) kinetic energy 
B) temperature 
C) energy 
D) work 
E) potential energy 
A) kinetic energy 
B) temperature 
C) energy 
D) work 
E) potential energy C

Question 3

Ethanol (CH3CH2OH) has been suggested as an alternative fuel source. Ethanol's enthalpy of combustion is F1F1F1S1F1F1F10Hcomb F1F1F1S1F1F1F10 F1F1F1S1F1F1F101,368 kJ/mol, and its density is 0.789 g/mL. What is the fuel density of ethanol (kJ/mL)?

Accepted Answer

A) 3.75 kJ/mL 
B) 12.8 kJ/mL 
C) 1.28 kJ/mL 
D) 23.4 kJ/mL 
E) 37.5 kJ/mL 
A) 3.75 kJ/mL 
B) 12.8 kJ/mL 
C) 1.28 kJ/mL 
D) 23.4 kJ/mL 
E) 37.5 kJ/mL D

Question 4

Which of the following hydrocarbons has the lowest fuel value?

Accepted Answer

A) C3H8 
B) C9H20 
C) C14H30 
D) C8H18 
E) CH4 
A) C3H8 
B) C9H20 
C) C14H30 
D) C8H18 
E) CH4

Question 5

Which statement A-D about energy units is not correct?

Accepted Answer

A) The SI unit of energy is the Joule (J). 
B) In terms of SI base units, 1 J F1F1F1S1F1F1F10 1 kg m2 sF1F1F1S1F1F1F102. 
C) A nutritional calorie (1 Cal) is equal to 1,000 cal. 
D) A nutritional calorie (1 Cal) is 4.184 kJ. 
E) Statements A-D all are correct. 
A) The SI unit of energy is the Joule (J). 
B) In terms of SI base units, 1 J F1F1F1S1F1F1F10 1 kg m2 sF1F1F1S1F1F1F102. 
C) A nutritional calorie (1 Cal) is equal to 1,000 cal. 
D) A nutritional calorie (1 Cal) is 4.184 kJ. 
E) Statements A-D all are correct.

Question 6

Sports trainers use cold packs containing ammonium nitrate for injured athletes. Calculate the change in temperature when 47 g of ammonium nitrate (NH4NO3, 80.1 g/mol) dissolves in 100 g water. Assume the specific heat of the solution is 4.5 J/(g F1F1F1S1F1F1F10 F1F1F1S1F1F1F10C).
NH4NO3(s)   F1F1F1S1F1F1F10NH4F1F1F1S1F1F1F10(aq)   F1F1F1S1F1F1F10NO3F1F1F1S1F1F1F10(aq) F1F1F1S1F1F1F10H F1F1F1S1F1F1F10 21.1 kJ/mol

Accepted Answer

F1F1F1S1F

Question 7

Which of the following fuels has the lowest fuel value (kJ/g)?

Accepted Answer

A) natural gas, CH4(g), 16.0 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F10801 kJ/mol 
B) ethanol, CH3CH2OH(l), 46.1 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F101,368 kJ/mol 
C) heating oil, C16H34(l), 226 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F1010,800 kJ/mol 
D) coal, C135H96O9NS(s), 1906 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F1044,000 kJ/mol 
E) wood, C6H12O6(s), 180 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F102,540 kJ/mol 
A) natural gas, CH4(g), 16.0 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F10801 kJ/mol 
B) ethanol, CH3CH2OH(l), 46.1 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F101,368 kJ/mol 
C) heating oil, C16H34(l), 226 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F1010,800 kJ/mol 
D) coal, C135H96O9NS(s), 1906 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F1044,000 kJ/mol 
E) wood, C6H12O6(s), 180 g/mol,   F1F1F1S1F1F1F10Hcomb   F1F1F1S1F1F1F102,540 kJ/mol

Question 8

Given the standard enthalpies of formation for the following substances, determine the reaction enthalpy for the following reaction. 2N2H4(g)   F1F1F1S1F1F1F102NO2(g)   F1F1F1S1F1F1F103N2(g)   F1F1F1S1F1F1F104H2O(g) F1F1F1S1F1F1F10Hrxn F1F1F1S1F1F1F10 ? kJ
SubstanceF1F1F1S1F1F1F10H    in kJ/mol
N2H4(g)F1F1F1S1F1F1F1095.4
NO2(g)F1F1F1S1F1F1F1033.1
H2O(g)F1F1F1S1F1F1F10241.8

Accepted Answer

A) (F1F1F1S1F1F1F101,220 kJ) 
B) (F1F1F1S1F1F1F101,220 kJ) 
C) (F1F1F1S1F1F1F10967 kJ/mol) 
D) (F1F1F1S1F1F1F10967 kJ/mol) 
E) (F1F1F1S1F1F1F10257 kJ/mol) 
A) (F1F1F1S1F1F1F101,220 kJ) 
B) (F1F1F1S1F1F1F101,220 kJ) 
C) (F1F1F1S1F1F1F10967 kJ/mol) 
D) (F1F1F1S1F1F1F10967 kJ/mol) 
E) (F1F1F1S1F1F1F10257 kJ/mol)

Question 9

What is the kinetic energy of a skier weighing 175 lb traveling 60 mph? (2.205 lb = 1 kg, 1 mi = 1.609 km, 1 J = 1 kg m2s-2)

Accepted Answer

A) 29 kJ 
B) 57 kJ 
C) 2.1 kJ 
D) 1.1 kJ 
E) 130 kJ 
A) 29 kJ 
B) 57 kJ 
C) 2.1 kJ 
D) 1.1 kJ 
E) 130 kJ

Question 10

Which of the changes A-D will always increase the internal energy of a system?

Accepted Answer

A) The system gains energy and performs work. 
B) The system gains energy and work is performed on it. 
C) The system loses energy and performs work. 
D) The system loses energy and work is performed on it. 
E) None of the changes A-D will always increase the internal energy of a system. 
A) The system gains energy and performs work. 
B) The system gains energy and work is performed on it. 
C) The system loses energy and performs work. 
D) The system loses energy and work is performed on it. 
E) None of the changes A-D will always increase the internal energy of a system.

Question 11

If a chemical reaction causes the temperature of the container to drop, it is a(n) ________ reaction.

Accepted Answer

A) endothermic 
B) exothermic 
C) spontaneous 
D) fast 
E) slow 
A) endothermic 
B) exothermic 
C) spontaneous 
D) fast 
E) slow

Question 12

An expanding gas does 175 kJ of work on its surroundings at a constant pressure of 5.55 atm. If the gas initially occupied 125 mL, what is the final volume of the gas? (101.3 J F1F1F1S1F1F1F10 1 L atm)

Accepted Answer

A) 31.5 L 
B) 31,500 mL 
C) 311 mL 
D) 311 L 
E) 31,500 L 
A) 31.5 L 
B) 31,500 mL 
C) 311 mL 
D) 311 L 
E) 31,500 L

Question 13

When solid sodium hydroxide (NaOH) pellets are dissolved in water, the temperature of the water and beaker rises. This is an example of ________

Accepted Answer

A) an exothermic process. 
B) an endothermic process. 
C) a combustion reaction. 
D) a thermodynamic cycle. 
E) all solvation processes. 
A) an exothermic process. 
B) an endothermic process. 
C) a combustion reaction. 
D) a thermodynamic cycle. 
E) all solvation processes.

Question 14

The complete combustion of 2.500 g of cinnamaldehyde (C9H8O, 132.16 g/mol), which is a component in cinnamon, produces an increase in temperature of 26.65F1F1F1S1F1F1F10C in a bomb calorimeter (Ccal F1F1F1S1F1F1F10 3.640 kJ/F1F1F1S1F1F1F10C). What is the molar enthalpy of combustion of cinnamaldehyde in kJ/mol?

Accepted Answer

F1F1F1S1F

Question 15

The heating curve for a substance is shown below. The substance initially is a solid. It then becomes a liquid and a gas. Which of the line segments (I-V) represents the solid-to-liquid phase transition?

Accepted Answer

A) I 
B) II 
C) III 
D) IV 
E) V 
A) I 
B) II 
C) III 
D) IV 
E) V

Question 16

A food sample was burned in a bomb calorimeter containing 524 mL water. How much thermal energy was produced when the temperature of the water and the calorimeter rose from 20.0F1F1F1S1F1F1F10C to 25.0F1F1F1S1F1F1F10C? The metal calorimeter had a heat capacity of 725 J/F1F1F1S1F1F1F10C without the water. The specific heat capacity of water is 4.184 J/(g F1F1F1S1F1F1F10C).

Accepted Answer

A) 3.63 kJ 
B) 14.6 kJ 
C) 58.4 kJ 
D) 45.8 kJ 
E) 46.1 kJ 
A) 3.63 kJ 
B) 14.6 kJ 
C) 58.4 kJ 
D) 45.8 kJ 
E) 46.1 kJ

Question 17

Work requires ________

Accepted Answer

A) a use of potential energy. 
B) a release of kinetic energy. 
C) that a force moves an object. 
D) a change in temperature. 
E) the application of a force. 
A) a use of potential energy. 
B) a release of kinetic energy. 
C) that a force moves an object. 
D) a change in temperature. 
E) the application of a force.

Question 18

What is the change in internal energy (F1F1F1S1F1F1F10E) when a system is heated with 35 J of energy while it does 15 J of work?

Accepted Answer

A) (F1F1F1S1F1F1F1050 J) 
B) (F1F1F1S1F1F1F1020 J) 
C) (F1F1F1S1F1F1F1020 J) 
D) (F1F1F1S1F1F1F1050 J) 
E) (F1F1F1S1F1F1F1035 K) 
A) (F1F1F1S1F1F1F1050 J) 
B) (F1F1F1S1F1F1F1020 J) 
C) (F1F1F1S1F1F1F1020 J) 
D) (F1F1F1S1F1F1F1050 J) 
E) (F1F1F1S1F1F1F1035 K)

Question 19

Determine the enthalpy for the following reaction, given   (NH3(g)) F1F1F1S1F1F1F10 F1F1F1S1F1F1F1046.1 kJ/mol, F1F1F1S1F1F1F10F1F1F1S1F1F1F10   F1F1F1S1F1F1F10(NO(g))   F1F1F1S1F1F1F1090.3 kJ/mol, and   (H2O(g))   F1F1F1S1F1F1F10241.8 kJ/mol.
4NH3(g)   F1F1F1S1F1F1F105O2(g)   F1F1F1S1F1F1F104NO(g)   F1F1F1S1F1F1F106H2O(g) F1F1F1S1F1F1F10Hrxn   F1F1F1S1F1F1F10? kJ

Accepted Answer

F1F1F1S1F

Question 20

State Hess's law as it applies to changes in enthalpy.

Accepted Answer

The enthalpy change for a reac

The following diagrams illustrate the flow of energy (q) and work (w) in different processes. Which one is definitely an exothermic process?

Thermochemistry is the study of how ________ is produced and consumed during chemical reactions.

Ethanol (CH₃CH₂OH) has been suggested as an alternative fuel source. Ethanol's enthalpy of combustion is H_comb  1,368 kJ/mol, and its density is 0.789 g/mL. What is the fuel density of ethanol (kJ/mL)?

Which of the following hydrocarbons has the lowest fuel value?

Which statement A-D about energy units is not correct?

Which of the following fuels has the lowest fuel value (kJ/g)?

Given the standard enthalpies of formation for the following substances, determine the reaction enthalpy for the following reaction. 2N₂H₄(g) 2NO₂(g) 3N₂(g) 4H₂O(g) H_rxn  ? kJ SubstanceH in kJ/mol N₂H₄(g)95.4 NO₂(g)33.1 H₂O(g)241.8

What is the kinetic energy of a skier weighing 175 lb traveling 60 mph? (2.205 lb = 1 kg, 1 mi = 1.609 km, 1 J = 1 kg m²s^-2)

Which of the changes A-D will always increase the internal energy of a system?

If a chemical reaction causes the temperature of the container to drop, it is a(n) ________ reaction.

An expanding gas does 175 kJ of work on its surroundings at a constant pressure of 5.55 atm. If the gas initially occupied 125 mL, what is the final volume of the gas? (101.3 J  1 L atm)

When solid sodium hydroxide (NaOH) pellets are dissolved in water, the temperature of the water and beaker rises. This is an example of ________

The complete combustion of 2.500 g of cinnamaldehyde (C₉H₈O, 132.16 g/mol), which is a component in cinnamon, produces an increase in temperature of 26.65C in a bomb calorimeter (C_cal  3.640 kJ/C). What is the molar enthalpy of combustion of cinnamaldehyde in kJ/mol?

The heating curve for a substance is shown below. The substance initially is a solid. It then becomes a liquid and a gas. Which of the line segments (I-V) represents the solid-to-liquid phase transition?

Work requires ________

What is the change in internal energy (E) when a system is heated with 35 J of energy while it does 15 J of work?

Determine the enthalpy for the following reaction, given (NH₃(g))  46.1 kJ/mol,  (NO(g)) 90.3 kJ/mol, and (H₂O(g)) 241.8 kJ/mol. 4NH₃(g) 5O₂(g) 4NO(g) 6H₂O(g) H_rxn ? kJ

State Hess's law as it applies to changes in enthalpy.

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Properties of Gases: The Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Crystals, Alloys, and Polymers

Chemical Kinetics: Reactions in the Atmosphere

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acidbase Equilibria: Proton Transfer in Biological Systems

Additional Aqueous Equilibria: Chemistry and the Oceans

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: The Quest for Clean Energy

Nuclear Chemistry: Applications to Energy and Medicine

Organic and Biological Molecules: the Compounds of Life

The Main Group Elements: Life and the Periodic Table

Transition Metals: Biological and Medical Applications

Filters

Exam 5: Thermochemistry: Energy Changes in Reactions

The following diagrams illustrate the flow of energy (q) and work (w) in different processes. Which one is definitely an exothermic process?

Thermochemistry is the study of how ________ is produced and consumed during chemical reactions.

Ethanol (CH3CH2OH) has been suggested as an alternative fuel source. Ethanol's enthalpy of combustion is Hcomb  1,368 kJ/mol, and its density is 0.789 g/mL. What is the fuel density of ethanol (kJ/mL)?

Which of the following hydrocarbons has the lowest fuel value?

Which statement A-D about energy units is not correct?

Which of the following fuels has the lowest fuel value (kJ/g)?

Given the standard enthalpies of formation for the following substances, determine the reaction enthalpy for the following reaction. 2N2H4(g) 2NO2(g) 3N2(g) 4H2O(g) Hrxn  ? kJ SubstanceH in kJ/mol N2H4(g)95.4 NO2(g)33.1 H2O(g)241.8

What is the kinetic energy of a skier weighing 175 lb traveling 60 mph? (2.205 lb = 1 kg, 1 mi = 1.609 km, 1 J = 1 kg m2s-2)

Which of the changes A-D will always increase the internal energy of a system?

If a chemical reaction causes the temperature of the container to drop, it is a(n) ________ reaction.

An expanding gas does 175 kJ of work on its surroundings at a constant pressure of 5.55 atm. If the gas initially occupied 125 mL, what is the final volume of the gas? (101.3 J  1 L atm)

When solid sodium hydroxide (NaOH) pellets are dissolved in water, the temperature of the water and beaker rises. This is an example of ________

The complete combustion of 2.500 g of cinnamaldehyde (C9H8O, 132.16 g/mol), which is a component in cinnamon, produces an increase in temperature of 26.65C in a bomb calorimeter (Ccal  3.640 kJ/C). What is the molar enthalpy of combustion of cinnamaldehyde in kJ/mol?

The heating curve for a substance is shown below. The substance initially is a solid. It then becomes a liquid and a gas. Which of the line segments (I-V) represents the solid-to-liquid phase transition?

Work requires ________

What is the change in internal energy (E) when a system is heated with 35 J of energy while it does 15 J of work?

Determine the enthalpy for the following reaction, given (NH3(g))  46.1 kJ/mol,  (NO(g)) 90.3 kJ/mol, and (H2O(g)) 241.8 kJ/mol. 4NH3(g) 5O2(g) 4NO(g) 6H2O(g) Hrxn ? kJ

State Hess's law as it applies to changes in enthalpy.

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Properties of Gases: The Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Crystals, Alloys, and Polymers

Chemical Kinetics: Reactions in the Atmosphere

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acidbase Equilibria: Proton Transfer in Biological Systems

Additional Aqueous Equilibria: Chemistry and the Oceans

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: The Quest for Clean Energy

Nuclear Chemistry: Applications to Energy and Medicine

Organic and Biological Molecules: the Compounds of Life

The Main Group Elements: Life and the Periodic Table

Transition Metals: Biological and Medical Applications

Filters

Ethanol (CH₃CH₂OH) has been suggested as an alternative fuel source. Ethanol's enthalpy of combustion is H_comb  1,368 kJ/mol, and its density is 0.789 g/mL. What is the fuel density of ethanol (kJ/mL)?

Given the standard enthalpies of formation for the following substances, determine the reaction enthalpy for the following reaction. 2N₂H₄(g) 2NO₂(g) 3N₂(g) 4H₂O(g) H_rxn  ? kJ SubstanceH in kJ/mol N₂H₄(g)95.4 NO₂(g)33.1 H₂O(g)241.8

What is the kinetic energy of a skier weighing 175 lb traveling 60 mph? (2.205 lb = 1 kg, 1 mi = 1.609 km, 1 J = 1 kg m²s^-2)

The complete combustion of 2.500 g of cinnamaldehyde (C₉H₈O, 132.16 g/mol), which is a component in cinnamon, produces an increase in temperature of 26.65C in a bomb calorimeter (C_cal  3.640 kJ/C). What is the molar enthalpy of combustion of cinnamaldehyde in kJ/mol?

Determine the enthalpy for the following reaction, given (NH₃(g))  46.1 kJ/mol,  (NO(g)) 90.3 kJ/mol, and (H₂O(g)) 241.8 kJ/mol. 4NH₃(g) 5O₂(g) 4NO(g) 6H₂O(g) H_rxn ? kJ