Question 1

Calculate the standard entropy for the following reaction from standard molar entropies.
NH4ClO4(s)+ Al(s)$\rightarrow$ NH4Cl(s)+ Al2O3(s)

Accepted Answer

-69.01 J.K^-1.mol^-1

Question 2

A piece of equipment must be capable of containing water at temperatures well above its normal boiling point.If the piece of equipment withstands an internal pressure of no more than 10.0 atm,calculate the highest temperature at which the system can be safely operated.

Accepted Answer

169S1U1P1$\circ$S1S1P0C

Question 3

Which of the following has the largest molar entropy?

Accepted Answer

A) H2(g) 
B) KF(aq) 
C) CO2(s) 
D) CaO(s) 
E) He(l) 
A) H2(g) 
B) KF(aq) 
C) CO2(s) 
D) CaO(s) 
E) He(l) B

Question 4

Which of the following statements is true?

Accepted Answer

A) Labile is a term that refers to the thermodynamic tendency of a substance to decompose. B) A thermodynamically unstable compound is a compound with a positive standard free energy of formation. C) Spontaneous reactions always have $\Delta$SrS1U1P1$\circ$S1S1P0 > 0. D) Spontaneous reactions always have $\Delta$GrS1U1P1$\circ$S1S1P0 > 0. E) Spontaneous reactions always have $\Delta$HrS1U1P1$\circ$S1S1P0< 0. A) Labile is a term that refers to the thermodynamic tendency of a substance to decompose. B) A thermodynamically unstable compound is a compound with a positive standard free energy of formation. C) Spontaneous reactions always have $\Delta$SrS1U1P1$\circ$S1S1P0 > 0. D) Spontaneous reactions always have $\Delta$GrS1U1P1$\circ$S1S1P0 > 0. E) Spontaneous reactions always have $\Delta$HrS1U1P1$\circ$S1S1P0< 0.

Question 5

Which of the following is always true for a spontaneous process at constant temperature?

Accepted Answer

A) ($\Delta$Ssystem + $\Delta$Ssurroundings = q/T) B) ($\Delta$S > 0) C) ($\Delta$S = q/T) D) ($\Delta$Ssystem + $\Delta$Ssurroundings > 0) E) ($\Delta$S < q/T) A) ($\Delta$Ssystem + $\Delta$Ssurroundings = q/T) B) ($\Delta$S > 0) C) ($\Delta$S = q/T) D) ($\Delta$Ssystem + $\Delta$Ssurroundings > 0) E) ($\Delta$S < q/T)

Question 6

Which of the following statements is true?

Accepted Answer

A) The molar entropy does not depend on the structure of the compound. 
B) The molar entropy of H2O(l)is about the same as the molar entropy of ice. 
C) An isothermal process that leads to a decrease in free energy is spontaneous. 
D) If $\Delta$GrS1U1P1$\circ$S1S1P0> 0,then the reaction is spontaneous. 
E) All processes that give positive changes in energy are spontaneous. 
A) The molar entropy does not depend on the structure of the compound. 
B) The molar entropy of H2O(l)is about the same as the molar entropy of ice. 
C) An isothermal process that leads to a decrease in free energy is spontaneous. 
D) If $\Delta$GrS1U1P1$\circ$S1S1P0> 0,then the reaction is spontaneous. 
E) All processes that give positive changes in energy are spontaneous.

Question 7

The reaction 
CaO(s)+ H2O(l)→ Ca(OH)2(s)
Is spontaneous at 0oC.Pedict the sign of the reaction enthalpy and entropy,respectively.

Accepted Answer

A) (+and-) 
B) (-and -) 
C) + and + 
D) (- and +) 
E) (- and 0) 
A) (+and-) 
B) (-and -) 
C) + and + 
D) (- and +) 
E) (- and 0)

Question 8

Calculate the change in molar entropy when the pressure of argon is allowed to double isothermally (assume ideal behavior).

Accepted Answer

A) +1.39 J.K-1.mol-1  
B) (-1.39 J.K-1.mol-1 ) 
C) (-4.16 J.K-1.mol-1 ) 
D) (-5.76 J.K-1.mol-1 ) 
E) +5.76 J.K-1.mol-1  
A) +1.39 J.K-1.mol-1  
B) (-1.39 J.K-1.mol-1 ) 
C) (-4.16 J.K-1.mol-1 ) 
D) (-5.76 J.K-1.mol-1 ) 
E) +5.76 J.K-1.mol-1

Question 9

Estimate the minimum temperature at which magnetite can be reduced to iron by graphite. 
Fe3O4(s)+ 2C(s)$\rightarrow$ 2CO2(g)+ 3Fe(s)
$\Delta$SrS1U1P1$\circ$S1S1P0 = +351.44 J.K-1.mol-1
The standard molar enthalpies of formation of magnetite and CO2(g)are -1118.4 and -393.51 kJ.mol-1,respectively.

Accepted Answer

A) 670S1U1P1$\circ$S1S1P0C 
B) Magnetite cannot be reduced by carbon at any temperature. 
C) 787S1U1P1$\circ$S1S1P0C 
D) 943S1U1P1$\circ$S1S1P0C 
E) 1790S1U1P1$\circ$S1S1P0C 
A) 670S1U1P1$\circ$S1S1P0C 
B) Magnetite cannot be reduced by carbon at any temperature. 
C) 787S1U1P1$\circ$S1S1P0C 
D) 943S1U1P1$\circ$S1S1P0C 
E) 1790S1U1P1$\circ$S1S1P0C

Question 10

The sublimation of solid carbon dioxide is a spontaneous process.Predict the sign (+,-,or 0)of $\Delta$GrS1U1P1$\circ$S1S1P0,$\Delta$HrS1U1P1$\circ$S1S1P0,and $\Delta$SrS1U1P1$\circ$S1S1P0,respectively.

Accepted Answer

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

Question 11

Calculate the normal boiling point of chloroform,given that the standard entropy and enthalpy of vaporization of chloroform is +93.7 J.K-1.mol-1  and 31.4 J.K-1.mol-1

Accepted Answer

The answer of Calculate the normal boiling point of chloroform,given...

Question 12

For the reaction 
2C(s)+ 2H2(g)$\rightarrow$C2H4(g)
$\Delta$HrS1U1P1$\circ$S1S1P0 = +52.3 kJ.mol-1 and $\Delta$SrS1U1P1$\circ$S1S1P0 = -53.07 J.K-1.mol-1 at 298 K.This reaction will be spontaneous at

Accepted Answer

A) no temperature. 
B) all temperatures. 
C) temperatures below 985 K. 
D) temperatures above 985 K. 
E) temperatures below 1015 K. 
A) no temperature. 
B) all temperatures. 
C) temperatures below 985 K. 
D) temperatures above 985 K. 
E) temperatures below 1015 K.

Question 13

Rank the standard molar entropy of the following from lowest to highest.
1. H2O(l)
2. H2O(g)
3. H2O2(l)
4. H2O2(aq)

Accepted Answer

A) 4 < 1 < 3 < 2 
B) 1 < 3 < 4 < 2 
C) 3 < 1 < 4 < 2 
D) 2 < 4 < 3 < 1 
E) 1 < 3 < 2 < 4 
A) 4 < 1 < 3 < 2 
B) 1 < 3 < 4 < 2 
C) 3 < 1 < 4 < 2 
D) 2 < 4 < 3 < 1 
E) 1 < 3 < 2 < 4

Question 14

The molar entropy of Pb(s)at 298 K is equal to

Accepted Answer

A) CP × 298. 
B) zero. 
C) the sum of the integral of CPdT/T from 0 K to 298 K. 
A) CP × 298. 
B) zero. 
C) the sum of the integral of CPdT/T from 0 K to 298 K.

Question 15

Consider the compounds 
PCl5(g),HCN(g),CuO(s),NO(g),NH3(g),and SO2(g).
Which compound will become more stable with respect to its elements if the temperature is raised?

Accepted Answer

A) SO2(g) 
B) CuO(s) 
C) NH3(g) 
D) PCl5(g) 
E) NO(g) 
A) SO2(g) 
B) CuO(s) 
C) NH3(g) 
D) PCl5(g) 
E) NO(g)

Question 16

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

Accepted Answer

A) True 
 B)False

Question 17

Which of the following quantities is not equal to zero at 298 K?

Accepted Answer

A) ($\Delta$HfSS1U1P1$\circ$S1S1P0(H+(aq))) 
B) (SS1U1P1$\circ$S1S1P0(H2(g))) 
C) (SS1U1P1$\circ$S1S1P0(H+(aq)) 
D) ($\Delta$GfSS1U1P1$\circ$S1S1P0(H+(aq))) 
E) ($\Delta$HfSS1U1P1$\circ$S1S1P0(H2(g))) 
A) ($\Delta$HfSS1U1P1$\circ$S1S1P0(H+(aq))) 
B) (SS1U1P1$\circ$S1S1P0(H2(g))) 
C) (SS1U1P1$\circ$S1S1P0(H+(aq)) 
D) ($\Delta$GfSS1U1P1$\circ$S1S1P0(H+(aq))) 
E) ($\Delta$HfSS1U1P1$\circ$S1S1P0(H2(g)))

Question 18

The standard free energy of formation of benzene,C6H6(l),is +124.3 kJ.mol-1  at 298 K.This means that at 298 K benzene is thermodynamically unstable even though it can be kept indefinitely without decomposing.Explain.

Accepted Answer

Benzene is kinetical

Question 19

Which of the following would have the largest calculated value of the residual entropy?

Accepted Answer

A) C6H5Cl(s)(chlorobenzene) 
B) CO(s) 
C) N2O(s) 
D) FClO3(s) 
E) CCl4(s) 
A) C6H5Cl(s)(chlorobenzene) 
B) CO(s) 
C) N2O(s) 
D) FClO3(s) 
E) CCl4(s)

Question 20

Which of the following has the smallest entropy at 298 K?

Accepted Answer

A) Kr(g) 
B) Br2(l) 
C) Xe(g) 
D) Cl2(g) 
E) Br2(g) 
A) Kr(g) 
B) Br2(l) 
C) Xe(g) 
D) Cl2(g) 
E) Br2(g)

Calculate the standard entropy for the following reaction from standard molar entropies. NH₄ClO₄(s)+ Al(s) $\rightarrow$ NH₄Cl(s)+ Al₂O₃_(s)

A piece of equipment must be capable of containing water at temperatures well above its normal boiling point.If the piece of equipment withstands an internal pressure of no more than 10.0 atm,calculate the highest temperature at which the system can be safely operated.

Which of the following has the largest molar entropy?

Which of the following statements is true?

Which of the following is always true for a spontaneous process at constant temperature?

Which of the following statements is true?

The reaction CaO(s)+ H₂O(l)→ Ca(OH)₂(s) Is spontaneous at 0^oC.Pedict the sign of the reaction enthalpy and entropy,respectively.

Calculate the change in molar entropy when the pressure of argon is allowed to double isothermally (assume ideal behavior).

Estimate the minimum temperature at which magnetite can be reduced to iron by graphite. Fe₃O₄(s)+ 2C(s) $\rightarrow$ 2CO₂(g)+ 3Fe(s) $\Delta$ S_r^$\circ$ = +351.44 J.K^-1.mol^-1 The standard molar enthalpies of formation of magnetite and CO₂(g)are -1118.4 and -393.51 kJ.mol^-1,respectively.

The sublimation of solid carbon dioxide is a spontaneous process.Predict the sign (+,-,or 0)of $\Delta$ G_r^$\circ$, $\Delta$ H_r^$\circ$,and $\Delta$ S_r^$\circ$,respectively.

Calculate the normal boiling point of chloroform,given that the standard entropy and enthalpy of vaporization of chloroform is +93.7 J.K^-1.mol^-1 and 31.4 J.K^-1.mol^-1

For the reaction 2C(s)+ 2H₂(g) $\rightarrow$ C₂H₄(g) $\Delta$ H_r^$\circ$ = +52.3 kJ.mol^-1and $\Delta$ S_r^$\circ$ = -53.07 J.K^-1.mol^-1 at 298 K.This reaction will be spontaneous at

Rank the standard molar entropy of the following from lowest to highest. 1. H₂O(l) 2. H₂O(g) 3. H2O₂(l) 4. H₂O₂(aq)

The molar entropy of Pb(s)at 298 K is equal to

Consider the compounds PCl₅(g),HCN(g),CuO(s),NO(g),NH₃(g),and SO₂(g). Which compound will become more stable with respect to its elements if the temperature is raised?

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

Which of the following quantities is not equal to zero at 298 K?

The standard free energy of formation of benzene,C₆H₆(l),is +124.3 kJ.mol^-1 at 298 K.This means that at 298 K benzene is thermodynamically unstable even though it can be kept indefinitely without decomposing.Explain.

Which of the following would have the largest calculated value of the residual entropy?

Which of the following has the smallest entropy at 298 K?

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Exam 9: Thermodynamics: The Second and Third Laws

Calculate the standard entropy for the following reaction from standard molar entropies. NH4ClO4(s)+ Al(s) →\rightarrow→ NH4Cl(s)+ Al2O3(s)

A piece of equipment must be capable of containing water at temperatures well above its normal boiling point.If the piece of equipment withstands an internal pressure of no more than 10.0 atm,calculate the highest temperature at which the system can be safely operated.

Which of the following has the largest molar entropy?

Which of the following statements is true?

Which of the following is always true for a spontaneous process at constant temperature?

Which of the following statements is true?

The reaction CaO(s)+ H2O(l)→ Ca(OH)2(s) Is spontaneous at 0oC.Pedict the sign of the reaction enthalpy and entropy,respectively.

Calculate the change in molar entropy when the pressure of argon is allowed to double isothermally (assume ideal behavior).

Estimate the minimum temperature at which magnetite can be reduced to iron by graphite. Fe3O4(s)+ 2C(s) →\rightarrow→ 2CO2(g)+ 3Fe(s) Δ\DeltaΔ Sr ∘\circ∘ = +351.44 J.K-1.mol-1 The standard molar enthalpies of formation of magnetite and CO2(g)are -1118.4 and -393.51 kJ.mol-1,respectively.

The sublimation of solid carbon dioxide is a spontaneous process.Predict the sign (+,-,or 0)of Δ\DeltaΔ Gr ∘\circ∘ , Δ\DeltaΔ Hr ∘\circ∘ ,and Δ\DeltaΔ Sr ∘\circ∘ ,respectively.

Calculate the normal boiling point of chloroform,given that the standard entropy and enthalpy of vaporization of chloroform is +93.7 J.K-1.mol-1 and 31.4 J.K-1.mol-1

For the reaction 2C(s)+ 2H2(g) →\rightarrow→ C2H4(g) Δ\DeltaΔ Hr ∘\circ∘ = +52.3 kJ.mol-1 and Δ\DeltaΔ Sr ∘\circ∘ = -53.07 J.K-1.mol-1 at 298 K.This reaction will be spontaneous at

Rank the standard molar entropy of the following from lowest to highest. 1. H2O(l) 2. H2O(g) 3. H2O2(l) 4. H2O2(aq)

The molar entropy of Pb(s)at 298 K is equal to

Consider the compounds PCl5(g),HCN(g),CuO(s),NO(g),NH3(g),and SO2(g). Which compound will become more stable with respect to its elements if the temperature is raised?

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

Which of the following quantities is not equal to zero at 298 K?

The standard free energy of formation of benzene,C6H6(l),is +124.3 kJ.mol-1 at 298 K.This means that at 298 K benzene is thermodynamically unstable even though it can be kept indefinitely without decomposing.Explain.

Which of the following would have the largest calculated value of the residual entropy?

Which of the following has the smallest entropy at 298 K?

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Quantum Mechanics in Action: Atoms

Chemical Bonds

Molecular Shape and Structure

The Properties of Gases

Liquids and Solids

Inorganic Materials

Thermodynamics: The First Law

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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Calculate the standard entropy for the following reaction from standard molar entropies. NH₄ClO₄(s)+ Al(s) $\rightarrow$ NH₄Cl(s)+ Al₂O₃_(s)

The reaction CaO(s)+ H₂O(l)→ Ca(OH)₂(s) Is spontaneous at 0^oC.Pedict the sign of the reaction enthalpy and entropy,respectively.

The sublimation of solid carbon dioxide is a spontaneous process.Predict the sign (+,-,or 0)of $\Delta$ G_r^$\circ$, $\Delta$ H_r^$\circ$,and $\Delta$ S_r^$\circ$,respectively.

Calculate the normal boiling point of chloroform,given that the standard entropy and enthalpy of vaporization of chloroform is +93.7 J.K^-1.mol^-1 and 31.4 J.K^-1.mol^-1

For the reaction 2C(s)+ 2H₂(g) $\rightarrow$ C₂H₄(g) $\Delta$ H_r^$\circ$ = +52.3 kJ.mol^-1and $\Delta$ S_r^$\circ$ = -53.07 J.K^-1.mol^-1 at 298 K.This reaction will be spontaneous at

Rank the standard molar entropy of the following from lowest to highest. 1. H₂O(l) 2. H₂O(g) 3. H2O₂(l) 4. H₂O₂(aq)

Consider the compounds PCl₅(g),HCN(g),CuO(s),NO(g),NH₃(g),and SO₂(g). Which compound will become more stable with respect to its elements if the temperature is raised?

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

The standard free energy of formation of benzene,C₆H₆(l),is +124.3 kJ.mol^-1 at 298 K.This means that at 298 K benzene is thermodynamically unstable even though it can be kept indefinitely without decomposing.Explain.