Question 1

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 = 1 kg m2 s-2. 
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 = 1 kg m2 s-2. 
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 2

During an exothermic process, ________ for the system.

Accepted Answer

A) q > 0 B) w > 0 C) ($\Delta$H > 0) D) ($\Delta$H < 0) E) q + w = 0 A) q > 0 B) w > 0 C) ($\Delta$H > 0) D) ($\Delta$H < 0) E) q + w = 0

Question 3

Which of the following bar charts shows the correct internal energy changes that occur when a propane grill is used to cook a steak? (Consider the propane combustion reaction to be the system. Consider the grill, steak, and everything else to be the surroundings.)

Accepted Answer

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

Question 4

According to the first law of thermodynamics, which of the changes, A-D, will always increase the internal energy of a system? (q = energy transferred, and w = work done)

Accepted Answer

A)  q > 0, w  0, w > 0 
C)  q  0 
E)  None of the changes A-D will always increase the internal energy of a system. 
A)  q > 0, w  0, w > 0 
C)  q  0 
E)  None of the changes A-D will always increase the internal energy of a system.

Question 5

A new diet fad has just arrived! The idea is to drink cold water; the body has to burn up glucose to furnish the energy to warm the water to body temperature. OK, so let's see if this idea is reasonable. How many liters of water at 5°C would one have to drink to metabolize 1 kg (2.2 lbs) of glucose and lose that much weight? Body temperature is 37°C. Glucose is C6H12O6 (180 g/mol), and the enthalpy change for the metabolism of glucose is -2,802 kJ/mol.

Accepted Answer

Question 6

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

Accepted Answer

The enthalpy change for a reac

Question 7

The first law of thermodynamics implies that ________

Accepted Answer

A)  energy is transferred from the surroundings to the system during a combustion reaction. 
B)  if a system loses energy to the surroundings, then the surroundings must do an equal amount of work on the system. 
C)  if the surroundings gain energy from the system, then the system must lose an equal amount of energy. 
D)  energy is transferred from the system to the surroundings during a combustion reaction. 
E)  if a system does work on the surroundings, then the surroundings must transfer an equal amount of energy to the system. 
A)  energy is transferred from the surroundings to the system during a combustion reaction. 
B)  if a system loses energy to the surroundings, then the surroundings must do an equal amount of work on the system. 
C)  if the surroundings gain energy from the system, then the system must lose an equal amount of energy. 
D)  energy is transferred from the system to the surroundings during a combustion reaction. 
E)  if a system does work on the surroundings, then the surroundings must transfer an equal amount of energy to the system.

Question 8

The change in enthalpy and the change in internal energy of a system always will be equal when ________

Accepted Answer

A)  the process is exothermic. 
B)  the process is endothermic. 
C)  the process is isothermal. 
D)  the pressure is constant. 
E)  the volume is constant. 
A)  the process is exothermic. 
B)  the process is endothermic. 
C)  the process is isothermal. 
D)  the pressure is constant. 
E)  the volume is constant.

Question 9

Internal energy is defined as ________

Accepted Answer

A)  the total kinetic energy of all the system components. 
B)  the total potential energy of all the system components. 
C)  the total of the potential and kinetic energies of all the system components. 
D)  the total potential energy minus the total kinetic energy of all the system components. 
E)  the total kinetic energy minus the total potential energy of all the system components. 
A)  the total kinetic energy of all the system components. 
B)  the total potential energy of all the system components. 
C)  the total of the potential and kinetic energies of all the system components. 
D)  the total potential energy minus the total kinetic energy of all the system components. 
E)  the total kinetic energy minus the total potential energy of all the system components.

Question 10

Describe the difference between potential energy and kinetic energy, and give an example of each.

Accepted Answer

Potential energy is associated with the

Question 11

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?

Accepted Answer

Question 12

Complete the table below, and identify the fuel with the highest fuel value. $$\begin{array} { | l | c | c | c | c | } 
\hline  { \text { Substance } } & \begin{array} { c } 
\text { Model } \
\text { Compound }
\end{array} & \begin{array} { c } 
\text { Molar Mass } \
\text { (g/mol) }
\end{array} & \begin{array} { c } 
\text { Enthalpy of } \
\text { Combustion } \
\text { (kJ/mol) }
\end{array} & \begin{array} { c } 
\text { Fuel Value } \
\text { (kJ/g) }
\end{array} \
\hline \text { Natural gas } & \mathrm { CH } _ { 4 } & 16.04 & 801 & \
\hline \text { Petroleum gas } & \mathrm { C } _ { 3 } \mathrm { H } _ { 8 } & 44.10 & 2,040 & \
\hline \text { Heating oil } & \mathrm { C } _ { 14 } \mathrm { H } _ { 34 } & 226.0 & 10,800 & \
\hline \text { Coal } & \mathrm { C } _ { 135 } \mathrm { H } _ { 96 } \mathrm { O } _ { 9 } \mathrm { NS } & 1,906 & 44,000 & \
\hline \text { Wood } & \mathrm { C } _ { 6 } \mathrm { H } _ { 12 } \mathrm { O } _ { 6 } & 180.0 & 2,540 & \
\hline
\end{array}$$

Accepted Answer

Fuel values in kJ/g: Natural g

Question 13

How much energy is needed to change the temperature of 25.00 mL of water from 10.0°C to 95.0°C?
(CP = 75.38 J/(mol · °C), d = 1.00 g/mL)

Accepted Answer

A)  160 kJ 
B)  2,880 kJ 
C)  8.9 kJ 
D)  6.4 kJ 
E)  105 kJ 
A)  160 kJ 
B)  2,880 kJ 
C)  8.9 kJ 
D)  6.4 kJ 
E)  105 kJ

Question 14

Ammonium nitrate sometimes is used in cold packs because its enthalpy of solvation in water is +21 kJ/mol. What is the minimum amount of ammonium nitrate (80.05 g/mol) that is needed to cool a 1.0 L soft drink (d = 1.0 g/mL, specific heat 4.5 J g-1 °C-1) and its plastic bottle (heat capacity 50 J/K) from 30°C to 5°C.

Accepted Answer

A)  540 g 
B)  320 g 
C)  110 g 
D)  430 g 
E)  250 g 
A)  540 g 
B)  320 g 
C)  110 g 
D)  430 g 
E)  250 g

Question 15

Which substance has an enthalpy of formation equal to zero at 25oC and 1 atm?

Accepted Answer

A)  N2(g) 
B)  N2(l) 
C)  N2(s) 
D)  N(g) 
E)  N(s) 
A)  N2(g) 
B)  N2(l) 
C)  N2(s) 
D)  N(g) 
E)  N(s)

Question 16

Which statement regarding combustion of a sample of gasoline in a bomb calorimeter is correct?

Accepted Answer

A)  Work is done by the system on the surroundings. 
B)  Work is done by the surroundings on the system. 
C)  No work is done because the pressure is constant. 
D)  The work done by the system equals the energy produced by the system. 
E)  The experiment provides an accurate value for the change in energy, not the change in enthalpy. 
A)  Work is done by the system on the surroundings. 
B)  Work is done by the surroundings on the system. 
C)  No work is done because the pressure is constant. 
D)  The work done by the system equals the energy produced by the system. 
E)  The experiment provides an accurate value for the change in energy, not the change in enthalpy.

Question 17

In a steam engine, steam in a cylinder expands against a piston, exerting 10 atm of external pressure. The volume of the cylinder increases by 10 L and simultaneously the steam cools, losing 3,000 kJ of energy to the surroundings. What is the change in energy of the steam?
(101.3 J = 1 L atm)

Accepted Answer

A)  -3,010 kJ 
B)  -3,001 kJ 
C)  -3,100 kJ 
D)  -13,135 kJ 
E)  -2,990 kJ 
A)  -3,010 kJ 
B)  -3,001 kJ 
C)  -3,100 kJ 
D)  -13,135 kJ 
E)  -2,990 kJ

Question 18

Which of the following bar charts shows the correct internal energy changes that occur in a pitcher of iced tea (system), the refrigerator (surroundings), and the universe, as the iced tea in the refrigerator cools?

Accepted Answer

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

Question 19

In an experiment, 74.3 g of metallic copper was heated to 100.0°C and then quickly dropped into 200.0 mL of water in a calorimeter. The heat capacity of the calorimeter with the water was
875 J/°C. The initial temperature of the calorimeter was 27.5°C, and the final temperature after addition of the metal was 29.8°C. What is the value of the specific heat capacity of copper?

Accepted Answer

A)  0.418 J/(g . °
C)  
B)  0.193 J/(g. °
C)  
C)  0.386 J/(g . °
C)  
D)  0.772 J/(g . °
C)  
E)  1.54 J/(g . °
C)  
A)  0.418 J/(g . °
C)  
B)  0.193 J/(g. °
C)  
C)  0.386 J/(g . °
C)  
D)  0.772 J/(g . °
C)  
E)  1.54 J/(g . °
C)

Question 20

Predict the temperature change produced by burning 3.55 g benzoic acid in a bomb calorimeter that has a heat capacity of 20.12 kJ/°C. The enthalpy of combustion of benzoic acid is
-26)43 kJ/g.

Accepted Answer

A)  1.171°C 
B)  2.33°C 
C)  4.66°C 
D)  9.33°C 
E)  18.6°C 
A)  1.171°C 
B)  2.33°C 
C)  4.66°C 
D)  9.33°C 
E)  18.6°C

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

During an exothermic process, ________ for the system.

Which of the following bar charts shows the correct internal energy changes that occur when a propane grill is used to cook a steak? (Consider the propane combustion reaction to be the system. Consider the grill, steak, and everything else to be the surroundings.)

According to the first law of thermodynamics, which of the changes, A-D, will always increase the internal energy of a system? (q = energy transferred, and w = work done)

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

The first law of thermodynamics implies that ________

The change in enthalpy and the change in internal energy of a system always will be equal when ________

Internal energy is defined as ________

Describe the difference between potential energy and kinetic energy, and give an example of each.

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?

Complete the table below, and identify the fuel with the highest fuel value. Substance Model Compound Molar Mass (g/mol) Enthalpy of Combustion (kJ/mol) Fuel Value (kJ/g) Natural gas 16.04 801 Petroleum gas 44.10 2,040 Heating oil 226.0 10,800 Coal 1,906 44,000 Wood 180.0 2,540

How much energy is needed to change the temperature of 25.00 mL of water from 10.0°C to 95.0°C? (C_P = 75.38 J/(mol · °C), d = 1.00 g/mL)

Which substance has an enthalpy of formation equal to zero at 25^oC and 1 atm?

Which statement regarding combustion of a sample of gasoline in a bomb calorimeter is correct?

In a steam engine, steam in a cylinder expands against a piston, exerting 10 atm of external pressure. The volume of the cylinder increases by 10 L and simultaneously the steam cools, losing 3,000 kJ of energy to the surroundings. What is the change in energy of the steam? (101.3 J = 1 L atm)

Which of the following bar charts shows the correct internal energy changes that occur in a pitcher of iced tea (system), the refrigerator (surroundings), and the universe, as the iced tea in the refrigerator cools?

Predict the temperature change produced by burning 3.55 g benzoic acid in a bomb calorimeter that has a heat capacity of 20.12 kJ/°C. The enthalpy of combustion of benzoic acid is -26)43 kJ/g.

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: Structures and Applications

Organic Chemistry: Fuels, Pharmaceuticals, Materials, and Life

Chemical Kinetics: Reactions in the Air We Breathe

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acid-Base and Solubility Equilibria: Reactions in Soil and Water

Metal Ions: Colorful and Essential

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: the Quest for Clean Energy

Biochemistry: the Compounds of Life

Nuclear Chemistry: Applications to Energy and Medicine

Life and the Periodic Table

Filters

Exam 5: Thermochemistry: Energy Changes in Reactions

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

During an exothermic process, ________ for the system.

Which of the following bar charts shows the correct internal energy changes that occur when a propane grill is used to cook a steak? (Consider the propane combustion reaction to be the system. Consider the grill, steak, and everything else to be the surroundings.)

According to the first law of thermodynamics, which of the changes, A-D, will always increase the internal energy of a system? (q = energy transferred, and w = work done)

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

The first law of thermodynamics implies that ________

The change in enthalpy and the change in internal energy of a system always will be equal when ________

Internal energy is defined as ________

Describe the difference between potential energy and kinetic energy, and give an example of each.

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?

Complete the table below, and identify the fuel with the highest fuel value. Substance Model Compound Molar Mass (g/mol) Enthalpy of Combustion (kJ/mol) Fuel Value (kJ/g) Natural gas 16.04 801 Petroleum gas 44.10 2,040 Heating oil 226.0 10,800 Coal 1,906 44,000 Wood 180.0 2,540

How much energy is needed to change the temperature of 25.00 mL of water from 10.0°C to 95.0°C? (CP = 75.38 J/(mol · °C), d = 1.00 g/mL)

Which substance has an enthalpy of formation equal to zero at 25oC and 1 atm?

Which statement regarding combustion of a sample of gasoline in a bomb calorimeter is correct?

In a steam engine, steam in a cylinder expands against a piston, exerting 10 atm of external pressure. The volume of the cylinder increases by 10 L and simultaneously the steam cools, losing 3,000 kJ of energy to the surroundings. What is the change in energy of the steam? (101.3 J = 1 L atm)

Which of the following bar charts shows the correct internal energy changes that occur in a pitcher of iced tea (system), the refrigerator (surroundings), and the universe, as the iced tea in the refrigerator cools?

Predict the temperature change produced by burning 3.55 g benzoic acid in a bomb calorimeter that has a heat capacity of 20.12 kJ/°C. The enthalpy of combustion of benzoic acid is -26)43 kJ/g.

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: Structures and Applications

Organic Chemistry: Fuels, Pharmaceuticals, Materials, and Life

Chemical Kinetics: Reactions in the Air We Breathe

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acid-Base and Solubility Equilibria: Reactions in Soil and Water

Metal Ions: Colorful and Essential

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: the Quest for Clean Energy

Biochemistry: the Compounds of Life

Nuclear Chemistry: Applications to Energy and Medicine

Life and the Periodic Table

Filters

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?

How much energy is needed to change the temperature of 25.00 mL of water from 10.0°C to 95.0°C? (C_P = 75.38 J/(mol · °C), d = 1.00 g/mL)

Which substance has an enthalpy of formation equal to zero at 25^oC and 1 atm?