Question 1

Which of the following statements is false?

Accepted Answer

A)  Breaking bonds is always endothermic. 
B)  Bond enthalpies quantify the energy change for the complete separation of two bonded atoms in a molecule at constant pressure. 
C)  Bond enthalpy values are based on molecules in the gas phase. 
D)  Breaking weak bonds and making an equal number of strong bonds is exothermic. 
E)  Breaking weak bonds and making a greater number of equally weak bonds is endothermic. 
A)  Breaking bonds is always endothermic. 
B)  Bond enthalpies quantify the energy change for the complete separation of two bonded atoms in a molecule at constant pressure. 
C)  Bond enthalpy values are based on molecules in the gas phase. 
D)  Breaking weak bonds and making an equal number of strong bonds is exothermic. 
E)  Breaking weak bonds and making a greater number of equally weak bonds is endothermic.

Question 2

What is the molar heat capacity of aluminum (specific heat = 0.902 J g-1 °C-1)?

Accepted Answer

A)  0.034 J mol-1 °C-1 
B)  24.8 J mol-1 °C-1 
C)  29.3 J mol-1 °C-1 
D)  120 J mol-1 °C-1 
E)  1.5 × 1025 J mol-1 °C-1 
A)  0.034 J mol-1 °C-1 
B)  24.8 J mol-1 °C-1 
C)  29.3 J mol-1 °C-1 
D)  120 J mol-1 °C-1 
E)  1.5 × 1025 J mol-1 °C-1

Question 3

The standard enthalpies of formation for several substances are given below:   Calculate the DH° for the reaction below.

Accepted Answer

A)  -881.4 kJ 
B)  -811.8 kJ 
C)  -149.6 kJ 
D)  +149.6 kJ 
E)  +213.4 kJ 
A)  -881.4 kJ 
B)  -811.8 kJ 
C)  -149.6 kJ 
D)  +149.6 kJ 
E)  +213.4 kJ

Question 4

Which of the following is an example of potential energy?

Accepted Answer

A)  holding a baseball 
B)  running around bases 
C)  pitching a baseball 
D)  swinging a bat 
E)  sliding into home plate 
A)  holding a baseball 
B)  running around bases 
C)  pitching a baseball 
D)  swinging a bat 
E)  sliding into home plate

Question 5

What is the enthalpy change for the combustion of 4.73 g C4H10 in excess oxygen?

Accepted Answer

A)  -23200 kJ 
B)  -8960 kJ 
C)  -401 kJ 
D)  -154 kJ 
E)  -32.7 kJ 
A)  -23200 kJ 
B)  -8960 kJ 
C)  -401 kJ 
D)  -154 kJ 
E)  -32.7 kJ

Question 6

Determine if each of the four processes below describes positive or negative changes to the internal energy of the system.
I. water absorbs heat from the surroundings and becomes steam
II. steam expands and pushes against the surrounding air
III. fuel molecules burn and heat the surroundings
IV. air is compressed into an inner tube by an external pump

Accepted Answer

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

Question 7

How much energy in kilojoules is required to vaporize a 25.0 g sample of water at 100.0°C? The heat of vaporization of water = 2260 J g-1 at 100°C.

Accepted Answer

Question 8

Which process is exothermic?

Accepted Answer

A)  freezing rain drops 
B)  evaporating alcohol 
C)  defrosting frozen food 
D)  warming milk 
E)  subliming dry ice 
A)  freezing rain drops 
B)  evaporating alcohol 
C)  defrosting frozen food 
D)  warming milk 
E)  subliming dry ice

Question 9

A sample of water containing 2.00 moles is initially at 30.0°C. If the sample absorbs 2.00 kJ of heat, what is the final temperature of the water? (specific heat of water = 4.184 J g-1 °C-1)

Accepted Answer

A)  13.3°C 
B)  30.2°C 
C)  43.3°C 
D)  46.7°C 
E)  269°C 
A)  13.3°C 
B)  30.2°C 
C)  43.3°C 
D)  46.7°C 
E)  269°C

Question 10

The temperature of 3.50 kg of water is raised by 1.17°C when 1.00 g of hydrazine N2H4 is burned in a bomb calorimeter. The calorimeter has a heat capacity of 883 J/°C. How much heat is given off by the sample? The specific heat of water = 4.184 J g-1 °C-1.

Accepted Answer

A)  0.944 kJ 
B)  16.3 kJ 
C)  17.1 kJ 
D)  18.2 kJ 
E)  21.5 kJ 
A)  0.944 kJ 
B)  16.3 kJ 
C)  17.1 kJ 
D)  18.2 kJ 
E)  21.5 kJ

Question 11

What is the enthalpy change when 22.5 g of CH4 are burned in excess O2?

Accepted Answer

A)  -39.5 kJ 
B)  -890 kJ 
C)  -1250 kJ 
D)  +890 kJ 
E)  +1250 kJ 
A)  -39.5 kJ 
B)  -890 kJ 
C)  -1250 kJ 
D)  +890 kJ 
E)  +1250 kJ

Question 12

How much energy is required to raise the temperature of 200.0 g of water by 25.0°C? The specific heat of water = 4.184 J g-1 °C-1.

Accepted Answer

A)  20.9 kJ 
B)  9.36 kJ 
C)  10.5 kJ 
D)  210 kJ 
E)  1200 kJ 
A)  20.9 kJ 
B)  9.36 kJ 
C)  10.5 kJ 
D)  210 kJ 
E)  1200 kJ

Question 13

When does an endothermic reaction occur?

Accepted Answer

A)  when the enthalpy of the reactants is greater than the enthalpy of the products 
B)  when bonds are formed 
C)  when the energy of bonds breaking is greater than the energy of bonds formed 
D)  when the energy of bonds breaking is less than the energy of bonds formed 
E)  when stronger bonds are formed and weaker bonds are broken 
A)  when the enthalpy of the reactants is greater than the enthalpy of the products 
B)  when bonds are formed 
C)  when the energy of bonds breaking is greater than the energy of bonds formed 
D)  when the energy of bonds breaking is less than the energy of bonds formed 
E)  when stronger bonds are formed and weaker bonds are broken

Question 14

How much heat is required to melt 125 g of ice at 0°C? The enthalpy of fusion of ice = 333 J g-1 at 0 °C.

Accepted Answer

A)  0.375 J 
B)  41.6 kJ 
C)  283 kJ 
D)  333 J 
E)  523 J 
A)  0.375 J 
B)  41.6 kJ 
C)  283 kJ 
D)  333 J 
E)  523 J

Question 15

How much energy in kilojoules is required to raise the temperature of 20.0 g of water from 22.0°C to 37.0°C? The specific heat of water = 4.184 J g-1 °C-1.

Accepted Answer

Question 16

The standard enthalpies of formation for several substances are given below:   Calculate the DH° for the reaction below.

Accepted Answer

A)  -219.0 kJ 
B)  -69.2 kJ 
C)  34.6 kJ 
D)  69.2 kJ 
E)  219.0 kJ 
A)  -219.0 kJ 
B)  -69.2 kJ 
C)  34.6 kJ 
D)  69.2 kJ 
E)  219.0 kJ

Question 17

How many joules are there in one glass of milk containing 110 Calories?

Accepted Answer

A)  4.6 × 105 J 
B)  460 kJ 
C)  2.6 × 104 J 
D)  26 J 
E)  0.46 J 
A)  4.6 × 105 J 
B)  460 kJ 
C)  2.6 × 104 J 
D)  26 J 
E)  0.46 J

Question 18

The standard enthalpies of formation for several substances are given below:   Determine the DH° for the reaction below.

Accepted Answer

A)  -366.4 kJ 
B)  -299.9 kJ 
C)  -298.5 kJ 
D)  -255.9 kJ 
E)  255.9 kJ 
A)  -366.4 kJ 
B)  -299.9 kJ 
C)  -298.5 kJ 
D)  -255.9 kJ 
E)  255.9 kJ

Question 19

A bomb calorimeter has a heat capacity of 783 J/°C and contains 254 g of water. How much energy is evolved or absorbed when the temperature of the calorimeter goes from 23.73°C to 26.01°C? The specific heat of water = 4.184 J g-1 °C-1.

Accepted Answer

A)  1.78 kJ evolved 
B)  2.42 kJ evolved 
C)  4.21 kJ evolved 
D)  2420 kJ absorbed 
E)  4210 kJ evolved 
A)  1.78 kJ evolved 
B)  2.42 kJ evolved 
C)  4.21 kJ evolved 
D)  2420 kJ absorbed 
E)  4210 kJ evolved

Question 20

The standard enthalpies of formation for several substances are given below:   Determine the DH° for the reaction below.

Accepted Answer

A)  -2322.5 kJ 
B)  -2219.9 kJ 
C)  -782.8 kJ 
D)  -575.2.7 kJ 
E)  +575.2 kJ 
A)  -2322.5 kJ 
B)  -2219.9 kJ 
C)  -782.8 kJ 
D)  -575.2.7 kJ 
E)  +575.2 kJ

Which of the following statements is false?

What is the molar heat capacity of aluminum (specific heat = 0.902 J g^-1 °C^-1)?

The standard enthalpies of formation for several substances are given below: Calculate the DH° for the reaction below.

Which of the following is an example of potential energy?

What is the enthalpy change for the combustion of 4.73 g C₄H₁₀ in excess oxygen?

How much energy in kilojoules is required to vaporize a 25.0 g sample of water at 100.0°C? The heat of vaporization of water = 2260 J g^-1 at 100°C.

Which process is exothermic?

A sample of water containing 2.00 moles is initially at 30.0°C. If the sample absorbs 2.00 kJ of heat, what is the final temperature of the water? (specific heat of water = 4.184 J g^-1 °C^-1)

The temperature of 3.50 kg of water is raised by 1.17°C when 1.00 g of hydrazine N₂H₄ is burned in a bomb calorimeter. The calorimeter has a heat capacity of 883 J/°C. How much heat is given off by the sample? The specific heat of water = 4.184 J g^-1 °C^-1.

What is the enthalpy change when 22.5 g of CH₄ are burned in excess O₂?

How much energy is required to raise the temperature of 200.0 g of water by 25.0°C? The specific heat of water = 4.184 J g^-1 °C^-1.

When does an endothermic reaction occur?

How much heat is required to melt 125 g of ice at 0°C? The enthalpy of fusion of ice = 333 J g^-1 at 0 °C.

How much energy in kilojoules is required to raise the temperature of 20.0 g of water from 22.0°C to 37.0°C? The specific heat of water = 4.184 J g^-1 °C^-1.

The standard enthalpies of formation for several substances are given below: Calculate the DH° for the reaction below.

How many joules are there in one glass of milk containing 110 Calories?

The standard enthalpies of formation for several substances are given below: Determine the DH° for the reaction below.

A bomb calorimeter has a heat capacity of 783 J/°C and contains 254 g of water. How much energy is evolved or absorbed when the temperature of the calorimeter goes from 23.73°C to 26.01°C? The specific heat of water = 4.184 J g^-1 °C^-1.

The standard enthalpies of formation for several substances are given below: Determine the DH° for the reaction below.

The Nature of Chemistry

Atoms and Elements

Chemical Compounds

Quantities of Reactants and Products

Chemical Reactions

Electron Configurations and the Periodic Table

Covalent Bonding

Molecular Structure

Gases and the Atmosphere

Liquids, Solids, and Materials

Chemical Kinetics: Rates of Reactions

Chemical Equilibrium

The Chemistry of Solutes and Solutions

Acids and Bases

Additional Aqueous Equilibria

Thermodynamics: Directionality of Chemical Reactions

Electrochemistry and Its Applications

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Exam 6: Energy and Chemical Reactions

Which of the following statements is false?

What is the molar heat capacity of aluminum (specific heat = 0.902 J g-1 °C-1)?

The standard enthalpies of formation for several substances are given below: Calculate the DH° for the reaction below.

Which of the following is an example of potential energy?

What is the enthalpy change for the combustion of 4.73 g C4H10 in excess oxygen?

How much energy in kilojoules is required to vaporize a 25.0 g sample of water at 100.0°C? The heat of vaporization of water = 2260 J g-1 at 100°C.

Which process is exothermic?

A sample of water containing 2.00 moles is initially at 30.0°C. If the sample absorbs 2.00 kJ of heat, what is the final temperature of the water? (specific heat of water = 4.184 J g-1 °C-1)

The temperature of 3.50 kg of water is raised by 1.17°C when 1.00 g of hydrazine N2H4 is burned in a bomb calorimeter. The calorimeter has a heat capacity of 883 J/°C. How much heat is given off by the sample? The specific heat of water = 4.184 J g-1 °C-1.

What is the enthalpy change when 22.5 g of CH4 are burned in excess O2?

How much energy is required to raise the temperature of 200.0 g of water by 25.0°C? The specific heat of water = 4.184 J g-1 °C-1.

When does an endothermic reaction occur?

How much heat is required to melt 125 g of ice at 0°C? The enthalpy of fusion of ice = 333 J g-1 at 0 °C.

How much energy in kilojoules is required to raise the temperature of 20.0 g of water from 22.0°C to 37.0°C? The specific heat of water = 4.184 J g-1 °C-1.

The standard enthalpies of formation for several substances are given below: Calculate the DH° for the reaction below.

How many joules are there in one glass of milk containing 110 Calories?

The standard enthalpies of formation for several substances are given below: Determine the DH° for the reaction below.

A bomb calorimeter has a heat capacity of 783 J/°C and contains 254 g of water. How much energy is evolved or absorbed when the temperature of the calorimeter goes from 23.73°C to 26.01°C? The specific heat of water = 4.184 J g-1 °C-1.

The standard enthalpies of formation for several substances are given below: Determine the DH° for the reaction below.

The Nature of Chemistry

Atoms and Elements

Chemical Compounds

Quantities of Reactants and Products

Chemical Reactions

Electron Configurations and the Periodic Table

Covalent Bonding

Molecular Structure

Gases and the Atmosphere

Liquids, Solids, and Materials

Chemical Kinetics: Rates of Reactions

Chemical Equilibrium

The Chemistry of Solutes and Solutions

Acids and Bases

Additional Aqueous Equilibria

Thermodynamics: Directionality of Chemical Reactions

Electrochemistry and Its Applications

Nuclear Chemistry

Filters

What is the molar heat capacity of aluminum (specific heat = 0.902 J g^-1 °C^-1)?

What is the enthalpy change for the combustion of 4.73 g C₄H₁₀ in excess oxygen?

How much energy in kilojoules is required to vaporize a 25.0 g sample of water at 100.0°C? The heat of vaporization of water = 2260 J g^-1 at 100°C.

A sample of water containing 2.00 moles is initially at 30.0°C. If the sample absorbs 2.00 kJ of heat, what is the final temperature of the water? (specific heat of water = 4.184 J g^-1 °C^-1)

The temperature of 3.50 kg of water is raised by 1.17°C when 1.00 g of hydrazine N₂H₄ is burned in a bomb calorimeter. The calorimeter has a heat capacity of 883 J/°C. How much heat is given off by the sample? The specific heat of water = 4.184 J g^-1 °C^-1.

What is the enthalpy change when 22.5 g of CH₄ are burned in excess O₂?

How much energy is required to raise the temperature of 200.0 g of water by 25.0°C? The specific heat of water = 4.184 J g^-1 °C^-1.

How much heat is required to melt 125 g of ice at 0°C? The enthalpy of fusion of ice = 333 J g^-1 at 0 °C.

How much energy in kilojoules is required to raise the temperature of 20.0 g of water from 22.0°C to 37.0°C? The specific heat of water = 4.184 J g^-1 °C^-1.

A bomb calorimeter has a heat capacity of 783 J/°C and contains 254 g of water. How much energy is evolved or absorbed when the temperature of the calorimeter goes from 23.73°C to 26.01°C? The specific heat of water = 4.184 J g^-1 °C^-1.