Question 1

In the combustion of coal,C(s),the C=O bonds are stronger than the O=O bond.

Accepted Answer

A) True 
 B)False

Question 2

For the reaction CO2(aq)$\rightarrow$ CO2(g),$\Delta$Hr = 19.4 kJ.mol-1  at 298.At constant temperature and pressure,which of the following statements is true?

Accepted Answer

A) w = 0 
B) ($\Delta$U = 2.48 kJ) 
C) ($\Delta$H  $\Delta$U) 
A) w = 0 
B) ($\Delta$U = 2.48 kJ) 
C) ($\Delta$H  $\Delta$U)

Question 3

The enthalpy of sublimation of a substance is related to its enthalpy of vaporization and enthalpy of fusion by the equation,$\Delta$Hsublimation = $\Delta$Hvaporization - $\Delta$Hfusion.True or false?

Accepted Answer

A) True 
 B)False

Question 4

If 2.00 mol of an ideal gas at 300 K and 3.00 atm expands from 6.00 L to 18.00 L and a final pressure of 1.20 atm in two steps: (1)the gas is cooled at constant volume until its pressure has fallen to 1.20 atm,and (2)it is heated and allowed to expand against a constant pressure of 1.20 atm until its volume reaches 18.00 L,which of the following is correct?

Accepted Answer

A) w = 0 for step (1)and w = -1.46 kJ for step (2) 
B) w = -4.57 kJ for the overall process 
C) w = -6.03 kJ for the overall process 
D) w = -4.57 kJ for step (1)and w = -1.46 kJ for step (2) 
E) w = 0 for the overall process 
A) w = 0 for step (1)and w = -1.46 kJ for step (2) 
B) w = -4.57 kJ for the overall process 
C) w = -6.03 kJ for the overall process 
D) w = -4.57 kJ for step (1)and w = -1.46 kJ for step (2) 
E) w = 0 for the overall process

Question 5

A CD player and its battery together do 500 kJ of work.The battery also releases 250 kJ of energy as heat and the CD player releases 50 kJ as heat due to friction from spinning.What is the change in internal energy of the system,with the system regarded as the battery and CD player together?

Accepted Answer

A) +200 kJ 
B) (-700 kJ) 
C) (-800 kJ) 
D) (-200 kJ) 
E) (-750 kJ) 
A) +200 kJ 
B) (-700 kJ) 
C) (-800 kJ) 
D) (-200 kJ) 
E) (-750 kJ)

Question 6

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol N2 at 298 K and 1 atm at constant pressure.

Accepted Answer

A) 75S1U1P1$\circ$S1S1P0C 
B) 159S1U1P1$\circ$S1S1P0C 
C) 80S1U1P1$\circ$S1S1P0C 
D) 82S1U1P1$\circ$S1S1P0C 
E) 92S1U1P1$\circ$S1S1P0C 
A) 75S1U1P1$\circ$S1S1P0C 
B) 159S1U1P1$\circ$S1S1P0C 
C) 80S1U1P1$\circ$S1S1P0C 
D) 82S1U1P1$\circ$S1S1P0C 
E) 92S1U1P1$\circ$S1S1P0C

Question 7

If the standard enthalpy of combustion of ethanol,C2H5OH(l),at 298 K is -1368 kJ.mol-1 ,what is the standard enthalpy of formation of ethanol? The standard enthalpies of formation of carbon dioxide and liquid water are -393.51 and -285.83 kJ.mol-1 ,respectively.

Accepted Answer

A) +688.7 kJ.mol-1  
B) (-344.3 kJ.mol-1 ) 
C) +276.5 kJ.mol-1  
D) (-276.5 kJ.mol-1 ) 
E) (-688.7 kJ.mol-1 ) 
A) +688.7 kJ.mol-1  
B) (-344.3 kJ.mol-1 ) 
C) +276.5 kJ.mol-1  
D) (-276.5 kJ.mol-1 ) 
E) (-688.7 kJ.mol-1 )

Question 8

If the standard reaction enthalpy for the reaction NO2(g)$\rightarrow$ NO(g)+ O(g)
Is needed,calculate it from the standard enthalpy of formation of ozone,+142.7 kJ.mol-1 ,and from the reactions listed below:
O2(g)$\rightarrow$ 2O(g)
$\Delta$H° = +498.4 kJ.mol-1 
NO(g)+ O3(g)$\rightarrow$ NO2(g)+ O2(g)
$\Delta$H° = -200 kJ.mol-1

Accepted Answer

A) +355 kJ.mol-1  
B) +555 kJ.mol-1  
C) +192 kJ.mol-1  
D) +592 kJ.mol-1  
E) +306 kJ.mol-1  
A) +355 kJ.mol-1  
B) +555 kJ.mol-1  
C) +192 kJ.mol-1  
D) +592 kJ.mol-1  
E) +306 kJ.mol-1

Question 9

A piece of a newly synthesized material of mass 25.0 g at 80.0S1U1P1$\circ$S1S1P0C is placed in a calorimeter containing 100.0 g of water at 20.0S1U1P1$\circ$S1S1P0C.If the final temperature of the system is 24.0S1U1P1$\circ$S1S1P0C,what is the specific heat capacity of this material?

Accepted Answer

A) 0.30 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1  
B) 7.46 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1  
C) 1.19 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1  
D) 4.76 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1  
E) 0.84 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1  
A) 0.30 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1  
B) 7.46 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1  
C) 1.19 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1  
D) 4.76 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1  
E) 0.84 J.g-1.(S1U1P1$\circ$S1S1P0
C) -1

Question 10

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol N2 at 298 K and 1 atm at constant volume.

Accepted Answer

A) 80S1U1P1$\circ$S1S1P0C 
B) 145S1U1P1$\circ$S1S1P0C 
C) 159S1U1P1$\circ$S1S1P0C 
D) 120S1U1P1$\circ$S1S1P0C 
E) 105S1U1P1$\circ$S1S1P0C 
A) 80S1U1P1$\circ$S1S1P0C 
B) 145S1U1P1$\circ$S1S1P0C 
C) 159S1U1P1$\circ$S1S1P0C 
D) 120S1U1P1$\circ$S1S1P0C 
E) 105S1U1P1$\circ$S1S1P0C

Question 11

When a solution of 1.691 g of silver nitrate is mixed with an excess of sodium chloride in a calorimeter of heat capacity 216 J.(S1U1P1$\circ$S1S1P0C)-1,the temperature rises 3.03S1U1P1$\circ$S1S1P0C.What is the reaction enthalpy?

Accepted Answer

A) (-65.7 kJ.mol-1 ) 
B) (-0.654 kJ.mol-1 ) 
C) (+111 kJ.mol-1 ) 
D) (+65.7 kJ.mol-1 ) 
E) (+0.654 kJ.mol-1 ) 
A) (-65.7 kJ.mol-1 ) 
B) (-0.654 kJ.mol-1 ) 
C) (+111 kJ.mol-1 ) 
D) (+65.7 kJ.mol-1 ) 
E) (+0.654 kJ.mol-1 )

Question 12

A battery does 35 kJ of work driving an electric motor and 7 kJ of heat are released.What is the change in internal energy of the system?

Accepted Answer

A) (-35 kJ) 
B) +42 kJ 
C) (-42 kJ) 
D) (-28 kJ) 
E) +28 kJ 
A) (-35 kJ) 
B) +42 kJ 
C) (-42 kJ) 
D) (-28 kJ) 
E) +28 kJ

Question 13

What is the standard enthalpy of formation of Br2(l)?

Accepted Answer

A) a positive value. 
B) a negative value. 
C) zero. 
D) a positive value if it is forming from ions or a solid. 
E) a negative value if it is forming from ions or a solid. 
A) a positive value. 
B) a negative value. 
C) zero. 
D) a positive value if it is forming from ions or a solid. 
E) a negative value if it is forming from ions or a solid.

Question 14

Hot coffee in a vacuum flask (thermos)is an example of a(n)__________________ (open,closed,isolated)system.

Accepted Answer

The answer of Hot coffee in a vacuum flask (thermos)is...

Question 15

Match the values with the correct enthalpy change.

Accepted Answer

The answer of Match the values with the correct enthalpy...

Question 16

Given the standard reaction enthalpies below: 
N2(g)+ O2 $\rightarrow$ 2NO(g)
$\Delta$H° = +180.5 kJ.mol-1 
2NO2(g)$\rightarrow$ N2(g)+ 2O2(g)
$\Delta$H° = -66.4 kJ.mol-1 
Calculate the standard reaction enthalpy for the oxidation of nitric oxide to nitrogen dioxide,shown below:
2NO(g)+ O2(g)$\rightarrow$ 2NO2(g)

Accepted Answer

A) (+114.1 kJ.mol-1 ) 
B) (+246.9 kJ.mol-1 ) 
C) (-114.1 kJ.mol-1 ) 
D) (-294.6 kJ.mol-1 ) 
E) (-246.9 kJ.mol-1 ) 
A) (+114.1 kJ.mol-1 ) 
B) (+246.9 kJ.mol-1 ) 
C) (-114.1 kJ.mol-1 ) 
D) (-294.6 kJ.mol-1 ) 
E) (-246.9 kJ.mol-1 )

Question 17

The heat flow for the reaction 
C2H6(g)+ 3.5O2(g)$\rightarrow$ 2CO2(g)+ 3H2O(l)
Measured in a bomb calorimeter is -1553.5 kJ/mol at 298 K.At this temperature,$\Delta$U is

Accepted Answer

A) (-1553.5 kJ/mol) 
B) (-1552.3 kJ/mol) 
C) (-1547.3 kJ/mol) 
D) (-1559.7 kJ/mol) 
A) (-1553.5 kJ/mol) 
B) (-1552.3 kJ/mol) 
C) (-1547.3 kJ/mol) 
D) (-1559.7 kJ/mol)

Question 18

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol BF3 at 298 K and 1 atm at constant pressure.

Accepted Answer

A) 82S1U1P1$\circ$S1S1P0C 
B) 80S1U1P1$\circ$S1S1P0C 
C) 159S1U1P1$\circ$S1S1P0C 
D) 75S1U1P1$\circ$S1S1P0C 
E) 92S1U1P1$\circ$S1S1P0C 
A) 82S1U1P1$\circ$S1S1P0C 
B) 80S1U1P1$\circ$S1S1P0C 
C) 159S1U1P1$\circ$S1S1P0C 
D) 75S1U1P1$\circ$S1S1P0C 
E) 92S1U1P1$\circ$S1S1P0C

Question 19

What is the total motional contribution to the molar internal energy of gaseous HCN?

Accepted Answer

A) 3RT 
B) 3.5RT 
C) 2.5RT 
D) RT 
E) 1.5RT 
A) 3RT 
B) 3.5RT 
C) 2.5RT 
D) RT 
E) 1.5RT

Question 20

Of the following,which is not a state function?

Accepted Answer

A) q 
B) T 
C) U 
D) H 
E) A and B 
A) q 
B) T 
C) U 
D) H 
E) A and B

In the combustion of coal,C(s),the C=O bonds are stronger than the O=O bond.

For the reaction CO₂(aq) $\rightarrow$ CO₂(g), $\Delta$ H_r = 19.4 kJ.mol^-1 at 298.At constant temperature and pressure,which of the following statements is true?

The enthalpy of sublimation of a substance is related to its enthalpy of vaporization and enthalpy of fusion by the equation, $\Delta$ H_sublimation = $\Delta$ H_vaporization - $\Delta$ H_fusion.True or false?

A CD player and its battery together do 500 kJ of work.The battery also releases 250 kJ of energy as heat and the CD player releases 50 kJ as heat due to friction from spinning.What is the change in internal energy of the system,with the system regarded as the battery and CD player together?

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol N₂ at 298 K and 1 atm at constant pressure.

If the standard enthalpy of combustion of ethanol,C₂H₅OH(l),at 298 K is -1368 kJ.mol^-1,what is the standard enthalpy of formation of ethanol? The standard enthalpies of formation of carbon dioxide and liquid water are -393.51 and -285.83 kJ.mol^-1,respectively.

A piece of a newly synthesized material of mass 25.0 g at 80.0^$\circ$C is placed in a calorimeter containing 100.0 g of water at 20.0^$\circ$C.If the final temperature of the system is 24.0^$\circ$C,what is the specific heat capacity of this material?

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol N₂ at 298 K and 1 atm at constant volume.

When a solution of 1.691 g of silver nitrate is mixed with an excess of sodium chloride in a calorimeter of heat capacity 216 J.(^$\circ$C)^-1,the temperature rises 3.03^$\circ$C.What is the reaction enthalpy?

A battery does 35 kJ of work driving an electric motor and 7 kJ of heat are released.What is the change in internal energy of the system?

What is the standard enthalpy of formation of Br₂(l)?

Hot coffee in a vacuum flask (thermos)is an example of a(n)__________________ (open,closed,isolated)system.

Match the values with the correct enthalpy change.

The heat flow for the reaction C₂H₆(g)+ 3.5O₂(g) $\rightarrow$ 2CO₂(g)+ 3H₂O(l) Measured in a bomb calorimeter is -1553.5 kJ/mol at 298 K.At this temperature, $\Delta$ U is

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol BF₃ at 298 K and 1 atm at constant pressure.

What is the total motional contribution to the molar internal energy of gaseous HCN?

Of the following,which is not a state function?

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Exam 8: Thermodynamics: The First Law

In the combustion of coal,C(s),the C=O bonds are stronger than the O=O bond.

For the reaction CO2(aq) →\rightarrow→ CO2(g), Δ\DeltaΔ Hr = 19.4 kJ.mol-1 at 298.At constant temperature and pressure,which of the following statements is true?

The enthalpy of sublimation of a substance is related to its enthalpy of vaporization and enthalpy of fusion by the equation, Δ\DeltaΔ Hsublimation = Δ\DeltaΔ Hvaporization - Δ\DeltaΔ Hfusion.True or false?

A CD player and its battery together do 500 kJ of work.The battery also releases 250 kJ of energy as heat and the CD player releases 50 kJ as heat due to friction from spinning.What is the change in internal energy of the system,with the system regarded as the battery and CD player together?

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol N2 at 298 K and 1 atm at constant pressure.

If the standard enthalpy of combustion of ethanol,C2H5OH(l),at 298 K is -1368 kJ.mol-1 ,what is the standard enthalpy of formation of ethanol? The standard enthalpies of formation of carbon dioxide and liquid water are -393.51 and -285.83 kJ.mol-1 ,respectively.

A piece of a newly synthesized material of mass 25.0 g at 80.0 ∘\circ∘ C is placed in a calorimeter containing 100.0 g of water at 20.0 ∘\circ∘ C.If the final temperature of the system is 24.0 ∘\circ∘ C,what is the specific heat capacity of this material?

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol N2 at 298 K and 1 atm at constant volume.

When a solution of 1.691 g of silver nitrate is mixed with an excess of sodium chloride in a calorimeter of heat capacity 216 J.( ∘\circ∘ C)-1,the temperature rises 3.03 ∘\circ∘ C.What is the reaction enthalpy?

A battery does 35 kJ of work driving an electric motor and 7 kJ of heat are released.What is the change in internal energy of the system?

What is the standard enthalpy of formation of Br2(l)?

Hot coffee in a vacuum flask (thermos)is an example of a(n)__________________ (open,closed,isolated)system.

Match the values with the correct enthalpy change.

The heat flow for the reaction C2H6(g)+ 3.5O2(g) →\rightarrow→ 2CO2(g)+ 3H2O(l) Measured in a bomb calorimeter is -1553.5 kJ/mol at 298 K.At this temperature, Δ\DeltaΔ U is

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol BF3 at 298 K and 1 atm at constant pressure.

What is the total motional contribution to the molar internal energy of gaseous HCN?

Of the following,which is not a state function?

The Quantum World

Quantum Mechanics in Action: Atoms

Chemical Bonds

Molecular Shape and Structure

The Properties of Gases

Liquids and Solids

Inorganic Materials

Thermodynamics: The Second and Third Laws

Physical Equilibria

Chemical Equilibria

Acids and Bases

Aqueous Equilibria

Electrochemistry

Chemical Kinetics

The Elements: the Main Group Elements

The Elements: The D Block

Nuclear Chemistry

Organic Chemistry I

Organic Chemistry II

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For the reaction CO₂(aq) $\rightarrow$ CO₂(g), $\Delta$ H_r = 19.4 kJ.mol^-1 at 298.At constant temperature and pressure,which of the following statements is true?

The enthalpy of sublimation of a substance is related to its enthalpy of vaporization and enthalpy of fusion by the equation, $\Delta$ H_sublimation = $\Delta$ H_vaporization - $\Delta$ H_fusion.True or false?

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol N₂ at 298 K and 1 atm at constant pressure.

If the standard enthalpy of combustion of ethanol,C₂H₅OH(l),at 298 K is -1368 kJ.mol^-1,what is the standard enthalpy of formation of ethanol? The standard enthalpies of formation of carbon dioxide and liquid water are -393.51 and -285.83 kJ.mol^-1,respectively.

A piece of a newly synthesized material of mass 25.0 g at 80.0^$\circ$C is placed in a calorimeter containing 100.0 g of water at 20.0^$\circ$C.If the final temperature of the system is 24.0^$\circ$C,what is the specific heat capacity of this material?

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol N₂ at 298 K and 1 atm at constant volume.

When a solution of 1.691 g of silver nitrate is mixed with an excess of sodium chloride in a calorimeter of heat capacity 216 J.(^$\circ$C)^-1,the temperature rises 3.03^$\circ$C.What is the reaction enthalpy?

What is the standard enthalpy of formation of Br₂(l)?

The heat flow for the reaction C₂H₆(g)+ 3.5O₂(g) $\rightarrow$ 2CO₂(g)+ 3H₂O(l) Measured in a bomb calorimeter is -1553.5 kJ/mol at 298 K.At this temperature, $\Delta$ U is

Calculate the final temperature when 2.50 kJ of energy is transferred as heat to 1.50 mol BF₃ at 298 K and 1 atm at constant pressure.