Question 1

Which of the following is true for ΔrG?

Accepted Answer

A) If ΔrG > 0,the reaction is spontaneous in the forward direction. 
B) If Q = 1,then DrG > ΔrG. 
C) If ΔrG ≠ 0,the reaction is spontaneous in both the reverse and forward directions. 
D) If ΔrG rG = 0. 
A) If ΔrG > 0,the reaction is spontaneous in the forward direction. 
B) If Q = 1,then DrG > ΔrG. 
C) If ΔrG ≠ 0,the reaction is spontaneous in both the reverse and forward directions. 
D) If ΔrG rG = 0.

Question 2

Below what temperature does the following reaction become nonspontaneous? 2HNO3(aq)+ NO(g)→ 3NO2(g)+ H2O(l)ΔrH = +136.5 kJ; ΔrS = +287.5 J K-1 mol-1

Accepted Answer

A) 39.2 K 
B) 151 K 
C) 475 K 
D) 4.75 × 103 K 
E) 298.17 K 
A) 39.2 K 
B) 151 K 
C) 475 K 
D) 4.75 × 103 K 
E) 298.17 K

Question 3

Estimate ?S1U1B1rS1U1B0G° for the following reaction at 449.0 K. 
CHS1U1B12S1U1B0O(g)+ 2HS1U1B12S1U1B0(g)? CHS1U1B14S1U1B0g)+ HS1U1B12S1U1B0O(g)$\quad$$\quad$?S1U1B1rS1U1B0H°= -94.9 kJ molS1U1P1-1S1S1P0; ?S1U1B1rS1U1B0S°= -224.2 J KS1U1P1-1S1S1P0 moS1U1P1-1S1S1P0

Accepted Answer

A) +5.8 kJ molS1U1P1-1S1S1P0 
B) +12.9 kJ molS1U1P1-1S1S1P0 
C) -101 kJ molS1U1P1-1S1S1P0 
D) +2.4 kJ molS1U1P1-1S1S1P0 
E) -4.2 kJ molS1U1P1-1S1S1P0 
A) +5.8 kJ molS1U1P1-1S1S1P0 
B) +12.9 kJ molS1U1P1-1S1S1P0 
C) -101 kJ molS1U1P1-1S1S1P0 
D) +2.4 kJ molS1U1P1-1S1S1P0 
E) -4.2 kJ molS1U1P1-1S1S1P0

Question 4

Given the following equation, 
$\quad$$\quad$$\quad$N2O(g)+ NO2(g)→ 3 NO(g)$\quad$$\quad$ΔrG° = -23.0 kJ mol-1
Calculate ΔrG° for the following reaction:
$\quad$$\quad$$\quad$9NO(g)→ 3N2O(g)+ 3NO2(g)

Accepted Answer

A) -23.0 kJ mol-1 
B) 69.0 kJ mol-1 
C) -69.0 kJ mol-1 
D) -7.67 kJ mol-1 
E) 23.0 kJ mol-1 
A) -23.0 kJ mol-1 
B) 69.0 kJ mol-1 
C) -69.0 kJ mol-1 
D) -7.67 kJ mol-1 
E) 23.0 kJ mol-1

Question 5

$\quad$
-Use the following thermodynamic values to calculate ?r  $ G^{0} $ .
$\Delta_{r}$$ H^{\circ} $ = -95 kJ $\mathrm { mol } ^ { - 1 }$ ,$\Delta_{r}$$S ^ { 0 }$ = -157 J $\mathrm { mol } ^ { - 1 }$ ,T = 298 K

Accepted Answer

A) -48 kJ $\mathrm { mol } ^ { - 1 }$ 
B) -68 kJ $\mathrm { mol } ^ { - 1 }$ 
C) + 39 kJ $\mathrm { mol } ^ { - 1 }$ 
D) -157 kJ $\mathrm { mol } ^ { - 1 }$ 
E) +142 kJ $\mathrm { mol } ^ { - 1 }$ 
A) -48 kJ $\mathrm { mol } ^ { - 1 }$ 
B) -68 kJ $\mathrm { mol } ^ { - 1 }$ 
C) + 39 kJ $\mathrm { mol } ^ { - 1 }$ 
D) -157 kJ $\mathrm { mol } ^ { - 1 }$ 
E) +142 kJ $\mathrm { mol } ^ { - 1 }$

Question 6

Determine the equilibrium constant for the following reaction at 498 K: 2 Hg(g)+ O2(g)→ 2HgO(s)ΔrH° = -304.2 kJ mol-1; $\quad$ΔrS° = -414.2 J K-1 mol-1

Accepted Answer

A) 1.87 × 1010 
B) 8.10 × 1031 
C) 2.31 × 10-22 
D) 5.34 × 10-11 
E) 4.33 × 1021 
A) 1.87 × 1010 
B) 8.10 × 1031 
C) 2.31 × 10-22 
D) 5.34 × 10-11 
E) 4.33 × 1021

Question 7

Calculate the equilibrium constant for the following reaction at 298 K: 
$\quad$2CO(g)+ O2(g)→ 2CO2(g)

Accepted Answer

A) 1.48 × 1090 
B) 4.68 × 1032 
C) 1.18 × 1014 
D) 9.32 × 1092 
E) 4.17 × 1063 
A) 1.48 × 1090 
B) 4.68 × 1032 
C) 1.18 × 1014 
D) 9.32 × 1092 
E) 4.17 × 1063

Question 8

Identify the change in state that does not have an increase in entropy.

Accepted Answer

A) water freezing 
B) water boiling 
C) ice melting 
D) dry ice subliming 
E) water evaporating 
A) water freezing 
B) water boiling 
C) ice melting 
D) dry ice subliming 
E) water evaporating

Question 9

Phosphorus and chlorine gases combine to produce phosphorus trichloride: 
$P _ { 2 }$ (g)+ $\mathrm { 3Cl } _ { 2 }$ (g)? $2 \mathrm { PCl } _ { 3 }$ (g) 
?rG° at 298 K for this reaction is -642.9 kJ mol-1.The value of ?rG at 298 K for a reaction mixture that consists of $1.8 \text { atm } P _ { 2 }$ $1.2 \mathrm {~atm} \mathrm { Cl } 2$ and $0.66 \text { atm } \mathrm { PCl } _ { 3 }$ is ________ kJ mol-1.

Accepted Answer

A) -5.51 × 103 
B) -90.0 
C) -71.1 
D) -4.87 × 103 
E) -647.8 
A) -5.51 × 103 
B) -90.0 
C) -71.1 
D) -4.87 × 103 
E) -647.8

Question 10

Use Hess's law to calculate ΔrG° using the following information: ClO(g)+ O3(g)→ Cl(g)+ 2O2(g)$\quad$$\quad$$\quad$$\quad$$\quad$ ΔrG° = ?
2O3(g)→ 3O2(g)$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$  ΔrG° = +489.6 kJ mol-1
Cl(g)+ O3(g)→ ClO(g)+ O2(g)$\quad$$\quad$ΔrG° = -34.5 kJ mol-1

Accepted Answer

A) -472.4 kJ mol-1 
B) -210.3 kJ mol-1 
C) +455.1 kJ mol-1 
D) +262.1 kJ mol-1 
E) +524.1 kJ mol-1 
A) -472.4 kJ mol-1 
B) -210.3 kJ mol-1 
C) +455.1 kJ mol-1 
D) +262.1 kJ mol-1 
E) +524.1 kJ mol-1

Question 11

Use the following thermodynamic values to calculate ?r  $G ^ { 0 }$ .
$\Delta_{r}$$ H^{\circ} $ = +95 kJ $\mathrm { mol } ^ { - 1 }$ ,$\Delta_{r}$$S ^ { 0 }$ = -157 J $\mathrm { mol } ^ { - 1 }$ ,T = 398 K

Accepted Answer

A) -48 kJ $\mathrm { mol } ^ { - 1 }$ 
B) -68 kJ $\mathrm { mol } ^ { - 1 }$ 
C) +39 kJ $\mathrm { mol } ^ { - 1 }$ 
D) +157 kJ $\mathrm { mol } ^ { - 1 }$ 
E) +142 kJ $\mathrm { mol } ^ { - 1 }$ 
A) -48 kJ $\mathrm { mol } ^ { - 1 }$ 
B) -68 kJ $\mathrm { mol } ^ { - 1 }$ 
C) +39 kJ $\mathrm { mol } ^ { - 1 }$ 
D) +157 kJ $\mathrm { mol } ^ { - 1 }$ 
E) +142 kJ $\mathrm { mol } ^ { - 1 }$

Question 12

Which of the following relationships is correct at constant T and P?

Accepted Answer

A) ΔrG is proportional to -ΔSuniv. 
B) ΔrG > 0 represents a spontaneous process. 
C) ΔrG > 0 represents an increase in kinetic energy. 
D) ΔrG rG is not a function of temperature. 
A) ΔrG is proportional to -ΔSuniv. 
B) ΔrG > 0 represents a spontaneous process. 
C) ΔrG > 0 represents an increase in kinetic energy. 
D) ΔrG rG is not a function of temperature.

Question 13

Given the following equation, 
$\quad$$\quad$N2O(g)+ NO2(g)→ 3NO(g)$\quad$$\quad$ΔrG° = -23.0 kJ mol-1
Calculate ΔrG° for the following reaction:
$\quad$$\quad$3N2O(g)+ 3NO2(g)→ 9NO(g)

Accepted Answer

A) -23.0 kJ mol-1 
B) 69.0 kJ mol-1 
C) -69.0 kJ mol-1 
D) -7.67 kJ mol-1 
E) 23.0 kJ mol-1 
A) -23.0 kJ mol-1 
B) 69.0 kJ mol-1 
C) -69.0 kJ mol-1 
D) -7.67 kJ mol-1 
E) 23.0 kJ mol-1

Question 14

For the following example,what is true about ΔrH and ΔrS? 
$\quad$$\quad$$\quad$$\quad$H2O(l)→ H2O(s)

Accepted Answer

A) a negative ΔrH and a negative ΔrS 
B) a positive ΔrH and a negative ΔrS 
C) a negative ΔrH and a positive ΔrS 
D) a positive ΔrH and a positive ΔrS 
E) ΔrH = 0 and a positive ΔrS 
A) a negative ΔrH and a negative ΔrS 
B) a positive ΔrH and a negative ΔrS 
C) a negative ΔrH and a positive ΔrS 
D) a positive ΔrH and a positive ΔrS 
E) ΔrH = 0 and a positive ΔrS

Question 15

Why is the quantity of energy required to recharge a battery greater than the quantity of work done?

Accepted Answer

Some of th

Question 16

Calculate ΔrG° at 298 K using the following information: 
$\quad$$\quad$$\quad$$\quad$$\quad$4HNO3(g)+ 5N2H4(l)→ 7N2(g)+ 12H2O(l)ΔrG° = ?
ΔfH° (kJ mol-1)-133.9 $\quad$$\quad$50.6 $\quad$$\quad$$\quad$-285.8
S°(J K-1 mol-1) 266.9 $\quad$$\quad$ 121.2 $\quad$191.6 $\quad$70.0

Accepted Answer

A) +4.90 × 103 kJ mol-1 
B) +3.90 × 103 kJ mol-1 
C) -2.04 × 103 kJ mol-1 
D) -3.15 × 103 kJ mol-1 
E) -3.30 × 103 kJ mol-1 
A) +4.90 × 103 kJ mol-1 
B) +3.90 × 103 kJ mol-1 
C) -2.04 × 103 kJ mol-1 
D) -3.15 × 103 kJ mol-1 
E) -3.30 × 103 kJ mol-1

Question 17

Calculate ΔrS° for the following reaction.The S° for each species is shown below the reaction. 
$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$$\quad$4NH3(g)+ 5O2(g)→ 4NO(g)+ 6H2O(g)
S°(J K-1 mol-1)$\quad$$\quad$192.8 $\quad$205.2 $\quad$$\quad$210.8 $\quad$$\quad$188.8

Accepted Answer

A) +287.4 J K-1 mol-1 
B) -401.2 J K-1 mol-1 
C) +160.0 J K-1 mol-1 
D) -336.6 J K-1 mol-1 
E) +178.8 J K-1 mol-1 
A) +287.4 J K-1 mol-1 
B) -401.2 J K-1 mol-1 
C) +160.0 J K-1 mol-1 
D) -336.6 J K-1 mol-1 
E) +178.8 J K-1 mol-1

Question 18

Identify the compound with the lowest standard Gibbs energy of formation.

Accepted Answer

A) NaCl(s) 
B) N2(g) 
C) NO(g) 
D) O3(g) 
E) Cl2(g) 
A) NaCl(s) 
B) N2(g) 
C) NO(g) 
D) O3(g) 
E) Cl2(g)

Question 19

Place the following in order of decreasing standard molar entropy. 
$\quad$NaCl(s)$\quad$Na3PO4(aq)$\quad$NaCl(aq)

Accepted Answer

A) NaCl(s)> NaCl(aq)> Na3PO4(aq) 
B) NaCl(aq)> NaCl(s)> Na3PO4(aq) 
C) Na3PO4(aq)> NaCl(aq)> NaCl(s) 
D) NaCl(s)> Na3PO4(aq)> NaCl(aq) 
E) NaCl(aq)> Na3PO4(aq)> NaCl(s) 
A) NaCl(s)> NaCl(aq)> Na3PO4(aq) 
B) NaCl(aq)> NaCl(s)> Na3PO4(aq) 
C) Na3PO4(aq)> NaCl(aq)> NaCl(s) 
D) NaCl(s)> Na3PO4(aq)> NaCl(aq) 
E) NaCl(aq)> Na3PO4(aq)> NaCl(s)

Question 20

Place the following in order of increasing molar entropy at 298 K. 
$\quad$$\quad$Ne $\quad$$\quad$Xe $\quad$$\quad$He $\quad$$\quad$Ar $\quad$$\quad$Kr

Accepted Answer

A) He < Kr < Ne < Ar < Xe 
B) Xe < Kr < Ar < Ne < He 
C) Ar < He < Ar < Ne < Kr 
D) Ar < Ne < Xe < Kr < He 
E) He < Ne < Ar < Kr < Xe 
A) He < Kr < Ne < Ar < Xe 
B) Xe < Kr < Ar < Ne < He 
C) Ar < He < Ar < Ne < Kr 
D) Ar < Ne < Xe < Kr < He 
E) He < Ne < Ar < Kr < Xe

Exam 17: Gibbs Energy and Thermodynamics

Which of the following is true for ΔrG?

Below what temperature does the following reaction become nonspontaneous? 2HNO3(aq)+ NO(g)→ 3NO2(g)+ H2O(l)ΔrH = +136.5 kJ; ΔrS = +287.5 J K-1 mol-1

Estimate ?rG° for the following reaction at 449.0 K. CH2O(g)+ 2H2(g)? CH4g)+ H2O(g) \quad\quad ?rH°= -94.9 kJ mol-1; ?rS°= -224.2 J K-1 mo-1

Given the following equation, \quad\quad\quad N2O(g)+ NO2(g)→ 3 NO(g) \quad\quad ΔrG° = -23.0 kJ mol-1 Calculate ΔrG° for the following reaction: \quad\quad\quad 9NO(g)→ 3N2O(g)+ 3NO2(g)

\quad -Use the following thermodynamic values to calculate ?r G0 G^{0} G0 . Δr\Delta_{r}Δr​H∘ H^{\circ} H∘ = -95 kJ mol−1\mathrm { mol } ^ { - 1 }mol−1 , Δr\Delta_{r}Δr​S0S ^ { 0 }S0 = -157 J mol−1\mathrm { mol } ^ { - 1 }mol−1 ,T = 298 K

Determine the equilibrium constant for the following reaction at 498 K: 2 Hg(g)+ O2(g)→ 2HgO(s)ΔrH° = -304.2 kJ mol-1; \quad ΔrS° = -414.2 J K-1 mol-1

Calculate the equilibrium constant for the following reaction at 298 K: \quad 2CO(g)+ O2(g)→ 2CO2(g)

Identify the change in state that does not have an increase in entropy.

Use Hess's law to calculate ΔrG° using the following information: ClO(g)+ O3(g)→ Cl(g)+ 2O2(g) \quad\quad\quad\quad\quad ΔrG° = ? 2O3(g)→ 3O2(g) \quad\quad\quad\quad\quad\quad\quad ΔrG° = +489.6 kJ mol-1 Cl(g)+ O3(g)→ ClO(g)+ O2(g) \quad\quad ΔrG° = -34.5 kJ mol-1

Use the following thermodynamic values to calculate ?r G0G ^ { 0 }G0 . Δr\Delta_{r}Δr​H∘ H^{\circ} H∘ = +95 kJ mol−1\mathrm { mol } ^ { - 1 }mol−1 , Δr\Delta_{r}Δr​S0S ^ { 0 }S0 = -157 J mol−1\mathrm { mol } ^ { - 1 }mol−1 ,T = 398 K

Which of the following relationships is correct at constant T and P?

Given the following equation, \quad\quad N2O(g)+ NO2(g)→ 3NO(g) \quad\quad ΔrG° = -23.0 kJ mol-1 Calculate ΔrG° for the following reaction: \quad\quad 3N2O(g)+ 3NO2(g)→ 9NO(g)

For the following example,what is true about ΔrH and ΔrS? \quad\quad\quad\quad H2O(l)→ H2O(s)

Why is the quantity of energy required to recharge a battery greater than the quantity of work done?

Calculate ΔrG° at 298 K using the following information: \quad\quad\quad\quad\quad 4HNO3(g)+ 5N2H4(l)→ 7N2(g)+ 12H2O(l)ΔrG° = ? ΔfH° (kJ mol-1)-133.9 \quad\quad 50.6 \quad\quad\quad -285.8 S°(J K-1 mol-1) 266.9 \quad\quad 121.2 \quad 191.6 \quad 70.0

Calculate ΔrS° for the following reaction.The S° for each species is shown below the reaction. \quad\quad\quad\quad\quad\quad\quad 4NH3(g)+ 5O2(g)→ 4NO(g)+ 6H2O(g) S°(J K-1 mol-1) \quad\quad 192.8 \quad 205.2 \quad\quad 210.8 \quad\quad 188.8

Identify the compound with the lowest standard Gibbs energy of formation.

Place the following in order of decreasing standard molar entropy. \quad NaCl(s) \quad Na3PO4(aq) \quad NaCl(aq)

Place the following in order of increasing molar entropy at 298 K. \quad\quad Ne \quad\quad Xe \quad\quad He \quad\quad Ar \quad\quad Kr

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Which of the following is true for Δ_rG?

Below what temperature does the following reaction become nonspontaneous? 2HNO₃(aq)+ NO(g)→ 3NO₂(g)+ H₂O(l)Δ_rH = +136.5 kJ; Δ_rS = +287.5 J K^-1 mol^-1

Estimate ?_rG° for the following reaction at 449.0 K. CH₂O(g)+ 2H₂(g)? CH₄g)+ H₂O(g) $\quad$ $\quad$ ?_rH°= -94.9 kJ mol^-1; ?_rS°= -224.2 J K^-1 mo^-1

Given the following equation, $\quad$ $\quad$ $\quad$ N₂O(g)+ NO₂(g)→ 3 NO(g) $\quad$ $\quad$ Δ_rG° = -23.0 kJ mol^-1 Calculate Δ_rG° for the following reaction: $\quad$ $\quad$ $\quad$ 9NO(g)→ 3N₂O(g)+ 3NO₂(g)

$\quad$ -Use the following thermodynamic values to calculate ?_r $G^{0}$ . $\Delta_{r}$ $H^{\circ}$ = -95 kJ $\mathrm { mol } ^ { - 1 }$ , $\Delta_{r}$ $S ^ { 0 }$ = -157 J $\mathrm { mol } ^ { - 1 }$ ,T = 298 K

Determine the equilibrium constant for the following reaction at 498 K: 2 Hg(g)+ O₂(g)→ 2HgO(s)Δ_rH° = -304.2 kJ mol^-1; $\quad$ Δ_rS° = -414.2 J K^-1 mol^-1

Calculate the equilibrium constant for the following reaction at 298 K: $\quad$ 2CO(g)+ O₂(g)→ 2CO₂(g)

Use the following thermodynamic values to calculate ?_r $G ^ { 0 }$ . $\Delta_{r}$ $H^{\circ}$ = +95 kJ $\mathrm { mol } ^ { - 1 }$ , $\Delta_{r}$ $S ^ { 0 }$ = -157 J $\mathrm { mol } ^ { - 1 }$ ,T = 398 K

Given the following equation, $\quad$ $\quad$ N₂O(g)+ NO₂(g)→ 3NO(g) $\quad$ $\quad$ Δ_rG° = -23.0 kJ mol^-1 Calculate Δ_rG° for the following reaction: $\quad$ $\quad$ 3N₂O(g)+ 3NO₂(g)→ 9NO(g)

For the following example,what is true about Δ_rH and Δ_rS? $\quad$ $\quad$ $\quad$ $\quad$ H₂O(l)→ H₂O(s)

Calculate Δ_rS° for the following reaction.The S° for each species is shown below the reaction. $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ $\quad$ 4NH₃(g)+ 5O₂(g)→ 4NO(g)+ 6H₂O(g) S°(J K^-1 mol^-1) $\quad$ $\quad$ 192.8 $\quad$ 205.2 $\quad$ $\quad$ 210.8 $\quad$ $\quad$ 188.8

Place the following in order of decreasing standard molar entropy. $\quad$ NaCl(s) $\quad$ Na₃PO₄(aq) $\quad$ NaCl(aq)

Place the following in order of increasing molar entropy at 298 K. $\quad$ $\quad$ Ne $\quad$ $\quad$ Xe $\quad$ $\quad$ He $\quad$ $\quad$ Ar $\quad$ $\quad$ Kr