Question 1

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 volume.

Accepted Answer

A) 100S1U1P1$\circ$S1S1P0C 
B) 80S1U1P1$\circ$S1S1P0C 
C) 67S1U1P1$\circ$S1S1P0C 
D) 125S1U1P1$\circ$S1S1P0C 
E) 92S1U1P1$\circ$S1S1P0C 
A) 100S1U1P1$\circ$S1S1P0C 
B) 80S1U1P1$\circ$S1S1P0C 
C) 67S1U1P1$\circ$S1S1P0C 
D) 125S1U1P1$\circ$S1S1P0C 
E) 92S1U1P1$\circ$S1S1P0C E

Question 2

Calculate the standard enthalpy of combustion of butane,C4H10(g),at 298 K from standard enthalpy of formation data.

Accepted Answer

-2877.04 kJ.mol^-1

Question 3

Calculate the standard enthalpy of formation of bicyco[1.1.0]butane (shown below)   
given the standard enthalpies of formation of C(g)and H(g),717 and 218 kJ.mol-1,respectively,and the average C-H and C-C bond enthalpies,412 and 348 kJ.mol-1,respectively.

Accepted Answer

A) +175 kJ.mol-1  
B) (-472 kJ.mol-1 ) 
C) +312 kJ.mol-1  
D) (-36 kJ.mol-1 ) 
E) (-124 kJ.mol-1 ) 
A) +175 kJ.mol-1  
B) (-472 kJ.mol-1 ) 
C) +312 kJ.mol-1  
D) (-36 kJ.mol-1 ) 
E) (-124 kJ.mol-1 ) D

Question 4

The standard enthalpy of formation of ammonium perchlorate at 298 K is -295.31 kJ.mol-1 .Write the equation that corresponds to this value.

Accepted Answer

½N₂(g)+ ½Cl_2</

Question 5

Calculate the standard enthalpy of combustion of ethanol at 298 K from standard enthalpy of formation data.

Accepted Answer

A) (-957.0 kJ.mol-1 ) 
B) (-1367 kJ.mol-1 ) 
C) (-687.5 kJ.mol-1 ) 
D) (-1922 kJ.mol-1 ) 
E) (-401.7 kJ.mol-1 ) 
A) (-957.0 kJ.mol-1 ) 
B) (-1367 kJ.mol-1 ) 
C) (-687.5 kJ.mol-1 ) 
D) (-1922 kJ.mol-1 ) 
E) (-401.7 kJ.mol-1 )

Question 6

Calculate the H-Br bond enthalpy given the standard enthalpies of formation for HBr(g),H(g),and Br(g): -36.2,218,and 112 kJ.mol-1 ,respectively.

Accepted Answer

A) 320 kJ.mol-1  
B) 366 kJ.mol-1  
C) 124 kJ.mol-1  
D) 284 kJ.mol-1  
E) 196 kJ.mol-1  
A) 320 kJ.mol-1  
B) 366 kJ.mol-1  
C) 124 kJ.mol-1  
D) 284 kJ.mol-1  
E) 196 kJ.mol-1

Question 7

If an isolated system contained +5 kJ of energy,after 100 years $\Delta$U =

Accepted Answer

A) The answer is impossible to determine 
B) Slightly less than +5 kJ. 
C) +5 kJ. 
D) 0 kJ. 
E) (-5 kJ.) 
A) The answer is impossible to determine 
B) Slightly less than +5 kJ. 
C) +5 kJ. 
D) 0 kJ. 
E) (-5 kJ.)

Question 8

The lattice enthalpy of calcium bromide is the energy change for the reaction

Accepted Answer

A) CaBr2(s)$\rightarrow$  Ca(g)+ 2Br(g) 
B) CaBr2(s)$\rightarrow$ Ca2+(g)+ 2Br-(g) 
C) Ca(s)+ Br2(l)$\rightarrow$ CaBr2(s) 
D) CaBr2(s)$\rightarrow$ Ca(g)+ Br2(g) 
E) Ca(g)+ 2Br(g)$\rightarrow$  CaBr2(g) 
A) CaBr2(s)$\rightarrow$  Ca(g)+ 2Br(g) 
B) CaBr2(s)$\rightarrow$ Ca2+(g)+ 2Br-(g) 
C) Ca(s)+ Br2(l)$\rightarrow$ CaBr2(s) 
D) CaBr2(s)$\rightarrow$ Ca(g)+ Br2(g) 
E) Ca(g)+ 2Br(g)$\rightarrow$  CaBr2(g)

Question 9

The temperature of a sample increases at its boiling point until all the liquid has been vaporized.

Accepted Answer

A) True 
 B)False

Question 10

Calculate the lattice enthalpy of potassium chloride given the following enthalpy data.

Accepted Answer

+717 kJ.mo

Question 11

For any isothermal process,$\Delta$U > 0 for an ideal gas.

Accepted Answer

A) True 
 B)False

Question 12

What can an isolated system exchange with the surroundings?

Accepted Answer

A) Energy only 
B) Matter only 
C) Energy and matter 
D) Neither energy or matter 
E) None of the above 
A) Energy only 
B) Matter only 
C) Energy and matter 
D) Neither energy or matter 
E) None of the above

Question 13

The combustion of 1 mole of ethanol,C2H5OH(l),in a bomb calorimeter released 1240 kJ of heat.The products of the reaction are carbon dioxide and liquid water.What is the enthalpy change for this reaction?

Accepted Answer

A) (-1245 kJ.mol-1 ) 
B) (-1235 kJ.mol-1 ) 
C) +1235 kJ.mol-1  
D) +1240 kJ.mol-1  
E) (-1240 kJ.mol-1 ) 
A) (-1245 kJ.mol-1 ) 
B) (-1235 kJ.mol-1 ) 
C) +1235 kJ.mol-1  
D) +1240 kJ.mol-1  
E) (-1240 kJ.mol-1 )

Question 14

What type of process is the formation of solid magnesium chloride from a gas of its ions?

Accepted Answer

A) a state function 
B) an adiabatic process 
C) an endothermic process 
D) an exothermic process 
E) not enough information is given to permit an answer 
A) a state function 
B) an adiabatic process 
C) an endothermic process 
D) an exothermic process 
E) not enough information is given to permit an answer

Question 15

The formation of solid calcium chloride from a gas of its ions is an exothermic process.

Accepted Answer

A) True 
 B)False

Question 16

In a system composed of nitrogen gas in a cylinder fitted with a piston,when 2.00 kJ of energy is transferred as heat at an external pressure of 2.00 atm,the nitrogen gas expands from 2.00 to 5.00 L against this constant pressure.What is $\Delta$U for the process?

Accepted Answer

A) (-0.608 kJ) 
B) +1.39 kJ 
C) +2.61 kJ 
D) 0 
E) (-2.61 kJ) 
A) (-0.608 kJ) 
B) +1.39 kJ 
C) +2.61 kJ 
D) 0 
E) (-2.61 kJ)

Question 17

Calculate the average H-S bond enthalpy in H2S(g)given the standard enthalpies of formation for H2S(g),H(g),and S(g): -20.1,218,and 223 kJ.mol-1 ,respectively.

Accepted Answer

A) 340 kJ.mol-1  
B) 231 kJ.mol-1  
C) 10.1 kJ.mol-1  
D) 679 kJ.mol-1  
E) 461 kJ.mol-1  
A) 340 kJ.mol-1  
B) 231 kJ.mol-1  
C) 10.1 kJ.mol-1  
D) 679 kJ.mol-1  
E) 461 kJ.mol-1

Question 18

Calculate the change in internal energy 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) +2.14 kJ 
B) (-1.79 kJ) 
C) +2.50 kJ 
D) (-2.50 kJ) 
E) +1.79 kJ 
A) +2.14 kJ 
B) (-1.79 kJ) 
C) +2.50 kJ 
D) (-2.50 kJ) 
E) +1.79 kJ

Question 19

Given the following standard reaction enthalpies: 
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 
And the standard enthalpy of formation of ozone,+142.7 kJ.mol-1 ,calculate the standard reaction enthalpy for the reaction
NO(g)+ O(g)$\rightarrow$NO2(g)

Accepted Answer

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

Question 20

For most reactions,the value of $\Delta$U is very close to that for $\Delta$H.

Accepted Answer

A) True 
 B)False

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 volume.

Calculate the standard enthalpy of combustion of butane,C₄H₁₀(g),at 298 K from standard enthalpy of formation data.

Calculate the standard enthalpy of formation of bicyco[1.1.0]butane (shown below) given the standard enthalpies of formation of C(g)and H(g),717 and 218 kJ.mol^-1,respectively,and the average C-H and C-C bond enthalpies,412 and 348 kJ.mol^-1,respectively.

The standard enthalpy of formation of ammonium perchlorate at 298 K is -295.31 kJ.mol^-1.Write the equation that corresponds to this value.

Calculate the standard enthalpy of combustion of ethanol at 298 K from standard enthalpy of formation data.

Calculate the H-Br bond enthalpy given the standard enthalpies of formation for HBr(g),H(g),and Br(g): -36.2,218,and 112 kJ.mol^-1,respectively.

If an isolated system contained +5 kJ of energy,after 100 years $\Delta$ U =

The lattice enthalpy of calcium bromide is the energy change for the reaction

The temperature of a sample increases at its boiling point until all the liquid has been vaporized.

Calculate the lattice enthalpy of potassium chloride given the following enthalpy data.

For any isothermal process, $\Delta$ U > 0 for an ideal gas.

What can an isolated system exchange with the surroundings?

The combustion of 1 mole of ethanol,C₂H₅OH(l),in a bomb calorimeter released 1240 kJ of heat.The products of the reaction are carbon dioxide and liquid water.What is the enthalpy change for this reaction?

What type of process is the formation of solid magnesium chloride from a gas of its ions?

The formation of solid calcium chloride from a gas of its ions is an exothermic process.

In a system composed of nitrogen gas in a cylinder fitted with a piston,when 2.00 kJ of energy is transferred as heat at an external pressure of 2.00 atm,the nitrogen gas expands from 2.00 to 5.00 L against this constant pressure.What is $\Delta$ U for the process?

Calculate the average H-S bond enthalpy in H₂S(g)given the standard enthalpies of formation for H₂S(g),H(g),and S(g): -20.1,218,and 223 kJ.mol^-1,respectively.

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

For most reactions,the value of $\Delta$ U is very close to that for $\Delta$ H.

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Exam 8: Thermodynamics: The First Law

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 volume.

Calculate the standard enthalpy of combustion of butane,C4H10(g),at 298 K from standard enthalpy of formation data.

Calculate the standard enthalpy of formation of bicyco[1.1.0]butane (shown below) given the standard enthalpies of formation of C(g)and H(g),717 and 218 kJ.mol-1,respectively,and the average C-H and C-C bond enthalpies,412 and 348 kJ.mol-1,respectively.

The standard enthalpy of formation of ammonium perchlorate at 298 K is -295.31 kJ.mol-1 .Write the equation that corresponds to this value.

Calculate the standard enthalpy of combustion of ethanol at 298 K from standard enthalpy of formation data.

Calculate the H-Br bond enthalpy given the standard enthalpies of formation for HBr(g),H(g),and Br(g): -36.2,218,and 112 kJ.mol-1 ,respectively.

If an isolated system contained +5 kJ of energy,after 100 years Δ\DeltaΔ U =

The lattice enthalpy of calcium bromide is the energy change for the reaction

The temperature of a sample increases at its boiling point until all the liquid has been vaporized.

Calculate the lattice enthalpy of potassium chloride given the following enthalpy data.

For any isothermal process, Δ\DeltaΔ U > 0 for an ideal gas.

What can an isolated system exchange with the surroundings?

The combustion of 1 mole of ethanol,C2H5OH(l),in a bomb calorimeter released 1240 kJ of heat.The products of the reaction are carbon dioxide and liquid water.What is the enthalpy change for this reaction?

What type of process is the formation of solid magnesium chloride from a gas of its ions?

The formation of solid calcium chloride from a gas of its ions is an exothermic process.

In a system composed of nitrogen gas in a cylinder fitted with a piston,when 2.00 kJ of energy is transferred as heat at an external pressure of 2.00 atm,the nitrogen gas expands from 2.00 to 5.00 L against this constant pressure.What is Δ\DeltaΔ U for the process?

Calculate the average H-S bond enthalpy in H2S(g)given the standard enthalpies of formation for H2S(g),H(g),and S(g): -20.1,218,and 223 kJ.mol-1 ,respectively.

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

For most reactions,the value of Δ\DeltaΔ U is very close to that for Δ\DeltaΔ H.

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

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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 volume.

Calculate the standard enthalpy of combustion of butane,C₄H₁₀(g),at 298 K from standard enthalpy of formation data.

Calculate the standard enthalpy of formation of bicyco[1.1.0]butane (shown below) given the standard enthalpies of formation of C(g)and H(g),717 and 218 kJ.mol^-1,respectively,and the average C-H and C-C bond enthalpies,412 and 348 kJ.mol^-1,respectively.

The standard enthalpy of formation of ammonium perchlorate at 298 K is -295.31 kJ.mol^-1.Write the equation that corresponds to this value.

Calculate the H-Br bond enthalpy given the standard enthalpies of formation for HBr(g),H(g),and Br(g): -36.2,218,and 112 kJ.mol^-1,respectively.

If an isolated system contained +5 kJ of energy,after 100 years $\Delta$ U =

For any isothermal process, $\Delta$ U > 0 for an ideal gas.

The combustion of 1 mole of ethanol,C₂H₅OH(l),in a bomb calorimeter released 1240 kJ of heat.The products of the reaction are carbon dioxide and liquid water.What is the enthalpy change for this reaction?

In a system composed of nitrogen gas in a cylinder fitted with a piston,when 2.00 kJ of energy is transferred as heat at an external pressure of 2.00 atm,the nitrogen gas expands from 2.00 to 5.00 L against this constant pressure.What is $\Delta$ U for the process?

Calculate the average H-S bond enthalpy in H₂S(g)given the standard enthalpies of formation for H₂S(g),H(g),and S(g): -20.1,218,and 223 kJ.mol^-1,respectively.

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

For most reactions,the value of $\Delta$ U is very close to that for $\Delta$ H.