Question 1

What mass of propane, C3H8(g),Must be burned to supply 2580 kJ of heat? The standard enthalpy of combustion of propane at 298 K is -2220 kJ.mol-1

Accepted Answer

A)  25.6 g 
B)  51.2 g 
C)  102 g 
D)  75.9 g 
E)  37.9 g 
A)  25.6 g 
B)  51.2 g 
C)  102 g 
D)  75.9 g 
E)  37.9 g

Question 2

Reactions with positive values of $\Delta$Sro always become spontaneous at low temperatures

Accepted Answer

A) True 
 B)False

Question 3

Which of the following statements is true?

Accepted Answer

A)  All exothermic reactions are spontaneous. 
B)  Any reaction that is spontaneous can be made spontaneous in the reverse direction by raising or lowering the temperature at which it is run, if the temperature change is large enough. 
C)  Any reaction that is spontaneous can not be spontaneous in the reverse direction. 
D)  A non-spontaneous reaction for which the entropy change is positive is entropy driven. 
A)  All exothermic reactions are spontaneous. 
B)  Any reaction that is spontaneous can be made spontaneous in the reverse direction by raising or lowering the temperature at which it is run, if the temperature change is large enough. 
C)  Any reaction that is spontaneous can not be spontaneous in the reverse direction. 
D)  A non-spontaneous reaction for which the entropy change is positive is entropy driven.

Question 4

Calculate $\Delta$Ssurr$\omicron$at 298 K for the reaction
H2(g)+ F2(g)$\rightarrow$ 2HF(g)
$\Delta$Hr° = -546 kJ.mol-1,
$\Delta$Sr° = +14.1 J.K-1.mol-1

Accepted Answer

A)  +14.1 J.K-1.mol-1  
B)  +1820 J.K-1.mol-1  
C)  +1830 J.K-1.mol-1  
D) -1830 J.K-1.mol-1  
E)  -14.1 J.K-1.mol-1  
A)  +14.1 J.K-1.mol-1  
B)  +1820 J.K-1.mol-1  
C)  +1830 J.K-1.mol-1  
D) -1830 J.K-1.mol-1  
E)  -14.1 J.K-1.mol-1

Question 5

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.

Accepted Answer

A) True 
 B)False

Question 6

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)...

Question 7

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

Accepted Answer

A) True 
 B)False

Question 8

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

Question 9

The sublimation of solid carbon dioxide is a spontaneous process .
Predict the sign (+,-,Or 0) f $\Delta$Gr$\omicron$,$\Delta$Hr$\omicron$,And $\Delta$Sr$\omicron$, Respectively.

Accepted Answer

A)  -0, 0, + 
B)  -, -,,- 
C)  -, +, + 
D)  0, +, + 
E)  -, +, - 
A)  -0, 0, + 
B)  -, -,,- 
C)  -, +, + 
D)  0, +, + 
E)  -, +, -

Question 10

All the halogens exist as diatomic molecules at room temperature and 1 bar.Under these conditions,which of the halogens,F to I,has the smallest molar entropy?

Accepted Answer

The answer of All the halogens exist as diatomic molecules...

Question 11

Consider the following processes (treat all gases as ideal).
1.The pressure of 1 mole of oxygen gas is allowed to double isothermally.
2.Carbon dioxide is allowed to expand isothermally to 10 times its original volume.
3.The temperature of 1 mol of helium is increased 25$\omicron $C at constant pressure.
4.Nitrogen gas is compressed isothermally to half its original volume.
5.A glass of water loses 100 J of energy reversibly at 30$\omicron $C.
Which of these processes lead(s)
To an increase in entropy?"

Accepted Answer

A)  1 and 4 
B)  5 
C)  3 and 5 
D)  2 and 3 
E)  1 and 2 
A)  1 and 4 
B)  5 
C)  3 and 5 
D)  2 and 3 
E)  1 and 2

Question 12

Calculate the standard entropy of vaporization of ethanol at its boiling point, 352 K.The standard molar enthalpy of vaporization of ethanol at its boiling point is 40.5 kJ.mol-1.

Accepted Answer

A)  +40.5 kJ.K-1.mol-1  
B)  +115 J.K-1.mol-1  
C)  -40.5 J.K-1.mol-1  
D)  +513 J.K-1.mol-1  
E)  -115 J.K-1.mol-1  
A)  +40.5 kJ.K-1.mol-1  
B)  +115 J.K-1.mol-1  
C)  -40.5 J.K-1.mol-1  
D)  +513 J.K-1.mol-1  
E)  -115 J.K-1.mol-1

Question 13

The temperature of 2.00 mol Ne(g) is increased from 25$\omicron $C to 200$\omicron $C at constant pressure. Calculate the change in the entropy of neon (assume ideal behavior).

Accepted Answer

A)  +7.68 kJ.mol-1  
B)  +19.2 kJ.mol-1  
C)  -7.68 kJ.mol-1  
D)  -19.2 kJ.mol-1  
E)  +9.60 kJ.mol-1  
A)  +7.68 kJ.mol-1  
B)  +19.2 kJ.mol-1  
C)  -7.68 kJ.mol-1  
D)  -19.2 kJ.mol-1  
E)  +9.60 kJ.mol-1

Question 14

The enthalpy of fusion of H2O(s) at its normal melting point is 6.01 kJ.mol-1.The entropy change for freezing 1 mol of water at this temperature is

Accepted Answer

A)  +20.2 J.K-1.mol-1  
B)  0 J.K-1.mol-1  
C)  -20.2 J.K-1.mol-1  
D)  +22.0 J.K-1.mol-1  
E) -22.0 J.K-1.mol-1  
A)  +20.2 J.K-1.mol-1  
B)  0 J.K-1.mol-1  
C)  -20.2 J.K-1.mol-1  
D)  +22.0 J.K-1.mol-1  
E) -22.0 J.K-1.mol-1

Question 15

$\Delta$U = 0 for the isothermal expansion of an ideal gas and therefore $\Delta$S =-0wrev/T = nRln(V2/V1).

Accepted Answer

A) True 
 B)False

Question 16

For the reaction
2SO3(g)$\rightarrow$2SO2(g)+ O2(g)
$\Delta$Hr$\omicron$= +198 J.K-1.mol-1  at 298 K.Which statement is true for this reaction?

Accepted Answer

A)  The reaction is driven by the enthalpy. 
B)  The reaction will not be spontaneous at low temperatures. 
C)  $\Delta$Gr$\omicron$will be negative at high temperatures. 
D)  The reaction will not be spontaneous at any temperature. 
E)  $\Delta$Gr$\omicron$will be positive at high temperatures. 
A)  The reaction is driven by the enthalpy. 
B)  The reaction will not be spontaneous at low temperatures. 
C)  $\Delta$Gr$\omicron$will be negative at high temperatures. 
D)  The reaction will not be spontaneous at any temperature. 
E)  $\Delta$Gr$\omicron$will be positive at high temperatures.

Question 17

for the reaction
N2O5(s)$\rightarrow$ 2NO2(g)+ ½O2(g),
$\Delta$Hr = 109.5 kJ.mol-1 at 298 K
at constant temperature and pressure,
$\Delta$H > $\Delta$U.

Accepted Answer

A) True 
 B)False

Question 18

For the reaction
2SO3(g)$\rightarrow$2SO2(g)+ O2(g)
$\Delta$Hr° = +198 kJ.mol-1 and $\Delta$Sr° = 190 J.K-1.mol-1 at 298 K.
The equilibrium constant for this reaction will be greater than 1 at

Accepted Answer

A)  all temperatures. 
B)  temperatures above 1315 K. 
C)  temperatures below 1042 K. 
D)  no temperature. 
E)  temperatures above 1042 K. 
A)  all temperatures. 
B)  temperatures above 1315 K. 
C)  temperatures below 1042 K. 
D)  no temperature. 
E)  temperatures above 1042 K.

Question 19

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 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

What mass of propane, C₃H₈(g),Must be burned to supply 2580 kJ of heat? The standard enthalpy of combustion of propane at 298 K is -2220 kJ.mol^-¹

Reactions with positive values of $\Delta$ S_r^o always become spontaneous at low temperatures

Which of the following statements is true?

Calculate $\Delta$ S_surr^$\omicron$at 298 K for the reaction H₂(g)+ F₂(g) $\rightarrow$ 2HF(g) $\Delta$ H_r° = -546 kJ.mol^-¹, $\Delta$ S_r° = +14.1 J.K^-¹.mol^-¹

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.

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

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

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.

The sublimation of solid carbon dioxide is a spontaneous process . Predict the sign (+,-,Or 0) f $\Delta$ G_r^$\omicron$, $\Delta$ H_r^$\omicron$,And $\Delta$ S_r^$\omicron$, Respectively.

All the halogens exist as diatomic molecules at room temperature and 1 bar.Under these conditions,which of the halogens,F to I,has the smallest molar entropy?

Calculate the standard entropy of vaporization of ethanol at its boiling point, 352 K.The standard molar enthalpy of vaporization of ethanol at its boiling point is 40.5 kJ.mol^-¹.

The temperature of 2.00 mol Ne(g) is increased from 25^$\omicron$C to 200^$\omicron$C at constant pressure. Calculate the change in the entropy of neon (assume ideal behavior).

The enthalpy of fusion of H₂O(s) at its normal melting point is 6.01 kJ.mol^-¹.The entropy change for freezing 1 mol of water at this temperature is

$\Delta$ U = 0 for the isothermal expansion of an ideal gas and therefore $\Delta$ S =-0w_rev/T = nRln(V₂/V₁).

For the reaction 2SO₃(g) $\rightarrow$ 2SO₂(g)+ O₂(g) $\Delta$ H_r^$\omicron$= +198 J.K^-¹.mol^-¹ at 298 K.Which statement is true for this reaction?

for the reaction N₂O₅(s) $\rightarrow$ 2NO₂(g)+ ½O₂(g), $\Delta$ H_r = 109.5 kJ.mol^-¹at 298 K at constant temperature and pressure, $\Delta$ H > $\Delta$ U.

For the reaction 2SO₃(g) $\rightarrow$ 2SO₂(g)+ O₂(g) $\Delta$ H_r° = +198 kJ.mol^-¹ and $\Delta$ S_r° = 190 J.K^-¹.mol^-¹ at 298 K. The equilibrium constant for this reaction will be greater than 1 at

Of the following, which is not a state function?

Atoms

Molecules

States of Matter

Equilibrium

Reactions

Kinetics

The Main-Group Elements

The D-Block Elements

Nuclear Chemistry

Organic Chemistry

Filters

Exam 4: Thermodynamics

What mass of propane, C3H8(g),Must be burned to supply 2580 kJ of heat? The standard enthalpy of combustion of propane at 298 K is -2220 kJ.mol-1

Reactions with positive values of Δ\DeltaΔ Sro always become spontaneous at low temperatures

Which of the following statements is true?

Calculate Δ\DeltaΔ Ssurr ο\omicronο at 298 K for the reaction H2(g)+ F2(g) →\rightarrow→ 2HF(g) Δ\DeltaΔ Hr° = -546 kJ.mol-1, Δ\DeltaΔ Sr° = +14.1 J.K-1.mol-1

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.

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

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

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.

The sublimation of solid carbon dioxide is a spontaneous process . Predict the sign (+,-,Or 0) f Δ\DeltaΔ Gr ο\omicronο , Δ\DeltaΔ Hr ο\omicronο ,And Δ\DeltaΔ Sr ο\omicronο , Respectively.

All the halogens exist as diatomic molecules at room temperature and 1 bar.Under these conditions,which of the halogens,F to I,has the smallest molar entropy?

Calculate the standard entropy of vaporization of ethanol at its boiling point, 352 K.The standard molar enthalpy of vaporization of ethanol at its boiling point is 40.5 kJ.mol-1.

The temperature of 2.00 mol Ne(g) is increased from 25 ο\omicron ο C to 200 ο\omicron ο C at constant pressure. Calculate the change in the entropy of neon (assume ideal behavior).

The enthalpy of fusion of H2O(s) at its normal melting point is 6.01 kJ.mol-1.The entropy change for freezing 1 mol of water at this temperature is

Δ\DeltaΔ U = 0 for the isothermal expansion of an ideal gas and therefore Δ\DeltaΔ S =-0wrev/T = nRln(V2/V1).

For the reaction 2SO3(g) →\rightarrow→ 2SO2(g)+ O2(g) Δ\DeltaΔ Hr ο\omicronο = +198 J.K-1.mol-1 at 298 K.Which statement is true for this reaction?

for the reaction N2O5(s) →\rightarrow→ 2NO2(g)+ ½O2(g), Δ\DeltaΔ Hr = 109.5 kJ.mol-1 at 298 K at constant temperature and pressure, Δ\DeltaΔ H > Δ\DeltaΔ U.

For the reaction 2SO3(g) →\rightarrow→ 2SO2(g)+ O2(g) Δ\DeltaΔ Hr° = +198 kJ.mol-1 and Δ\DeltaΔ Sr° = 190 J.K-1.mol-1 at 298 K. The equilibrium constant for this reaction will be greater than 1 at

Of the following, which is not a state function?

Atoms

Molecules

States of Matter

Equilibrium

Reactions

Kinetics

The Main-Group Elements

The D-Block Elements

Nuclear Chemistry

Organic Chemistry

Filters

What mass of propane, C₃H₈(g),Must be burned to supply 2580 kJ of heat? The standard enthalpy of combustion of propane at 298 K is -2220 kJ.mol^-¹

Reactions with positive values of $\Delta$ S_r^o always become spontaneous at low temperatures

Calculate $\Delta$ S_surr^$\omicron$at 298 K for the reaction H₂(g)+ F₂(g) $\rightarrow$ 2HF(g) $\Delta$ H_r° = -546 kJ.mol^-¹, $\Delta$ S_r° = +14.1 J.K^-¹.mol^-¹

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.

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.

The sublimation of solid carbon dioxide is a spontaneous process . Predict the sign (+,-,Or 0) f $\Delta$ G_r^$\omicron$, $\Delta$ H_r^$\omicron$,And $\Delta$ S_r^$\omicron$, Respectively.

Calculate the standard entropy of vaporization of ethanol at its boiling point, 352 K.The standard molar enthalpy of vaporization of ethanol at its boiling point is 40.5 kJ.mol^-¹.

The temperature of 2.00 mol Ne(g) is increased from 25^$\omicron$C to 200^$\omicron$C at constant pressure. Calculate the change in the entropy of neon (assume ideal behavior).

The enthalpy of fusion of H₂O(s) at its normal melting point is 6.01 kJ.mol^-¹.The entropy change for freezing 1 mol of water at this temperature is

$\Delta$ U = 0 for the isothermal expansion of an ideal gas and therefore $\Delta$ S =-0w_rev/T = nRln(V₂/V₁).

For the reaction 2SO₃(g) $\rightarrow$ 2SO₂(g)+ O₂(g) $\Delta$ H_r^$\omicron$= +198 J.K^-¹.mol^-¹ at 298 K.Which statement is true for this reaction?

for the reaction N₂O₅(s) $\rightarrow$ 2NO₂(g)+ ½O₂(g), $\Delta$ H_r = 109.5 kJ.mol^-¹at 298 K at constant temperature and pressure, $\Delta$ H > $\Delta$ U.

For the reaction 2SO₃(g) $\rightarrow$ 2SO₂(g)+ O₂(g) $\Delta$ H_r° = +198 kJ.mol^-¹ and $\Delta$ S_r° = 190 J.K^-¹.mol^-¹ at 298 K. The equilibrium constant for this reaction will be greater than 1 at