Question 1

Under which of the following conditions would one mole of Ne have the highest entropy,S?

Accepted Answer

A) 29°C and 26 L 
B) 135°C and 26 L 
C) 29°C and 34 L 
D) 135°C and 34 L 
A) 29°C and 26 L 
B) 135°C and 26 L 
C) 29°C and 34 L 
D) 135°C and 34 L

Question 2

Which one of the following has the lowest standard molar entropy,S°,at 25°C?

Accepted Answer

A) C5H12(s) 
B) C9H20(l) 
C) C12H26(s) 
D) C18H38(l) 
A) C5H12(s) 
B) C9H20(l) 
C) C12H26(s) 
D) C18H38(l)

Question 3

Which statement is true about the formation of CaCO3(s)from CaO(s)and CO2(g)at 1.00 atm? CaO(s)+ CO2(g)→ CaCO3(s) ΔH° = -178.7 kJ and ΔS° = -150.4 J/K

Accepted Answer

A) The reaction is spontaneous at all temperatures. 
B) The reaction is spontaneous at high temperatures. 
C) The reaction is spontaneous at low temperatures. 
D) The reaction is not spontaneous at any temperature. 
A) The reaction is spontaneous at all temperatures. 
B) The reaction is spontaneous at high temperatures. 
C) The reaction is spontaneous at low temperatures. 
D) The reaction is not spontaneous at any temperature.

Question 4

The solubility of manganese(II)fluoride in water is 6.6 g/mL at 40°C and 4.8 g/L at 100°C.Based on these data,what is the sign of ΔH° and ΔS° for the process below? MnF2(s)⇌ Mn2+(aq)+ 2 F-(aq)

Accepted Answer

A) ΔH° is negative but the sign of ΔS° cannot be determined from this information. 
B) ΔH° is negative and ΔS° is definitely negative. 
C) ΔH° is positive but the sign of ΔS° cannot be determined from this information. 
D) ΔH° is positive and ΔS° is definitely negative. 
A) ΔH° is negative but the sign of ΔS° cannot be determined from this information. 
B) ΔH° is negative and ΔS° is definitely negative. 
C) ΔH° is positive but the sign of ΔS° cannot be determined from this information. 
D) ΔH° is positive and ΔS° is definitely negative.

Question 5

-According to the diagram above,

Accepted Answer

A) ΔG° is positive and is equal to a - b. 
B) ΔG° is positive and is equal to b - c. 
C) ΔG° is negative and is equal to b - c. 
D) ΔG° is negative and is equal to a - c. 
A) ΔG° is positive and is equal to a - b. 
B) ΔG° is positive and is equal to b - c. 
C) ΔG° is negative and is equal to b - c. 
D) ΔG° is negative and is equal to a - c.

Question 6

The synthesis of ethanol from ethylene and water proceeds using the following reaction. C2H4(g)+ H2O(l)C2H5OH(l)ΔGºrxn = -116.6 kJ/mol
Determine the Gibbs free energy if the pressure of the vessel is 325 atm at 570 K.

Accepted Answer

A) -27526 kJ/mole 
B) -89 kJ/mole 
C) -144.0 kJ/mole 
D) none of these 
A) -27526 kJ/mole 
B) -89 kJ/mole 
C) -144.0 kJ/mole 
D) none of these

Question 7

Which statement is true concerning the standard states of F2(g)and C12H22O11(aq)?

Accepted Answer

A) The standard state for F2(g)is the pure gas at 1 atm and for C12H22O11(aq)is the pure solid at 1 atm. 
B) The standard state for F2(g)is the pure gas at 1 mol/L and for C12H22O11(aq)is the pure solid at 1 atm. 
C) The standard state for F2(g)is the pure gas at 1 atm and for C12H22O11(aq)is the solution at a concentration of 1 mol/L. 
D) The standard state for F2(g)is the pure gas at 1 mol/L and for C12H22O11(aq)is the solution at a concentration of 1 mol/L. 
A) The standard state for F2(g)is the pure gas at 1 atm and for C12H22O11(aq)is the pure solid at 1 atm. 
B) The standard state for F2(g)is the pure gas at 1 mol/L and for C12H22O11(aq)is the pure solid at 1 atm. 
C) The standard state for F2(g)is the pure gas at 1 atm and for C12H22O11(aq)is the solution at a concentration of 1 mol/L. 
D) The standard state for F2(g)is the pure gas at 1 mol/L and for C12H22O11(aq)is the solution at a concentration of 1 mol/L.

Question 8

The entropy change associated with the expansion of one mole of an ideal gas from an initial volume of Vi to a final volume of Vf at constant temperature is given by the equation,ΔS = R ln (Vf/Vi).What is the entropy change associated with the expansion of five moles of an ideal gas from an initial volume of Vi to a final volume of Vf at constant temperature?

Accepted Answer

A) ΔS = R ln (Vf/Vi) 
B) ΔS = 5 mol × R ln (Vf/Vi) 
C) ΔS = R ln (Vf × 23/Vi) 
D) ΔS = R ln (Vf × 5!/Vi) 
A) ΔS = R ln (Vf/Vi) 
B) ΔS = 5 mol × R ln (Vf/Vi) 
C) ΔS = R ln (Vf × 23/Vi) 
D) ΔS = R ln (Vf × 5!/Vi)

Question 9

For the following reaction find Kp at 25°C and indicate whether Kp should increase or decrease as the temperature rises. NH4HS(s)⇌ H2S(g)+ NH3(g)ΔH° = 83.47 kJ and ΔG° = 17.5 kJ at 25°C.

Accepted Answer

A) Kp = 8.6 × 10-4 and Kp should increase as the temperature rises. 
B) Kp = 8.6 × 10-4 and Kp should decrease as the temperature rises. 
C) Kp = 1.2 × 103 and Kp should increase as the temperature rises. 
D) Kp = 1.2 × 103 and Kp should decrease as the temperature rises. 
A) Kp = 8.6 × 10-4 and Kp should increase as the temperature rises. 
B) Kp = 8.6 × 10-4 and Kp should decrease as the temperature rises. 
C) Kp = 1.2 × 103 and Kp should increase as the temperature rises. 
D) Kp = 1.2 × 103 and Kp should decrease as the temperature rises.

Question 10

The following pictures represent three equilibrium mixtures for the interconversion of A,B,and C molecules (unshaded spheres)into X,Y,and Z molecules (shaded spheres),respectively.What is the sign of ΔG ° for each of the three reactions?

Accepted Answer

A) ΔG °(1)= -;ΔG °(2)= +;ΔG °(3)= 0 
B) ΔG °(1)= -;ΔG °(2)= 0;ΔG °(3)= + 
C) ΔG °(1)= 0;ΔG °(2)= -;ΔG °(3)= + 
D) ΔG °(1)= +;ΔG °(2)= 0;ΔG °(3)= - 
A) ΔG °(1)= -;ΔG °(2)= +;ΔG °(3)= 0 
B) ΔG °(1)= -;ΔG °(2)= 0;ΔG °(3)= + 
C) ΔG °(1)= 0;ΔG °(2)= -;ΔG °(3)= + 
D) ΔG °(1)= +;ΔG °(2)= 0;ΔG °(3)= -

Question 11

Consider the reaction 2A(g)⇌ AS1U1B12S1U1B0(g).The following pictures represent two possible initial states and the equilibrium state of the system.  
-For initial state 1 what is the relationship between the reaction quotient,Qp,and the equilibrium constant,Kp?

Accepted Answer

A) Qp p 
B) Qp = Kp = 1 
C) Qp = Kp ≠ 1 
D) Qp > Kp 
A) Qp p 
B) Qp = Kp = 1 
C) Qp = Kp ≠ 1 
D) Qp > Kp

Question 12

-According to the diagram above,the forward reaction is

Accepted Answer

A) nonspontaneous at d and e,and spontaneous at f. 
B) nonspontaneous at d,at equilibrium at e,and spontaneous at f. 
C) spontaneous at d,at equilibrium at e,and nonspontaneous at f. 
D) spontaneous at d,e,and f. 
A) nonspontaneous at d and e,and spontaneous at f. 
B) nonspontaneous at d,at equilibrium at e,and spontaneous at f. 
C) spontaneous at d,at equilibrium at e,and nonspontaneous at f. 
D) spontaneous at d,e,and f.

Question 13

The standard molar entropy for Br2(g)is 245.46 J/(mol ∙ K)at 25°C.Given that ΔS° = 104.58 J/K for the dissociation of one mole of Br2(g)into Br(g)at 25°C,find the standard molar entropy for Br(g)at 25°C.

Accepted Answer

A) 70.44 J/(mol ∙ K) 
B) 140.08 J/(mol ∙ K) 
C) 175.02 J/(mol ∙ K) 
D) 350.04 J/(mol ∙ K) 
A) 70.44 J/(mol ∙ K) 
B) 140.08 J/(mol ∙ K) 
C) 175.02 J/(mol ∙ K) 
D) 350.04 J/(mol ∙ K)

Question 14

Standard molar entropies,S°,in J/Kmol,are given below each reactant and product in the reaction shown below.The standard entropy of reaction,ΔS°,for this reaction is ________ J/K.
2 SO2(g)+ O2(g)→ 2 SO3(g)
248.1 205.0 256.6

Accepted Answer

Question 15

For the process CaCO3(calcite)→ CaCO3(aragonite)ΔH° = -0.21 kJ,ΔS° = -4.2 J/K
Assuming that the surroundings can be considered a large heat reservoir at 25°C,calculate ΔSsurr and ΔStotal for the process at 25°C and 1 atm pressure.Is the process spontaneous at 25°C and 1 atm pressure?

Accepted Answer

A) ΔSsurr = 4.2 J/K,Δtotal = 0,not spontaneous 
B) ΔSsurr = 0.7 J/K,ΔStotal = -3.5 J/K,not spontaneous 
C) ΔSsurr = -0.7 J/K,ΔStotal = -4.9 J/K,spontaneous 
D) ΔSsurr = -0.7 J/K,ΔStotal = -4.9 J/K,not spontaneous 
A) ΔSsurr = 4.2 J/K,Δtotal = 0,not spontaneous 
B) ΔSsurr = 0.7 J/K,ΔStotal = -3.5 J/K,not spontaneous 
C) ΔSsurr = -0.7 J/K,ΔStotal = -4.9 J/K,spontaneous 
D) ΔSsurr = -0.7 J/K,ΔStotal = -4.9 J/K,not spontaneous

Question 16

Which of the three laws of thermodynamics states the criterion for spontaneity?

Accepted Answer

A) the first law of thermodynamics 
B) the second law of thermodynamics 
C) the third law of thermodynamics 
D) both the second and third laws of thermodynamics 
A) the first law of thermodynamics 
B) the second law of thermodynamics 
C) the third law of thermodynamics 
D) both the second and third laws of thermodynamics

Question 17

Which has the lowest entropy?

Accepted Answer

A) CH3OH(s,-26°
C)  
B) CH3OH(s,-13°
C)  
C) CH3OH(l,16°
C)  
D) CH3OH(l,30°
C)  
A) CH3OH(s,-26°
C)  
B) CH3OH(s,-13°
C)  
C) CH3OH(l,16°
C)  
D) CH3OH(l,30°
C)

Question 18

The sign (+ or -)of ΔH is ________ and the sign (+ or -)of ΔS is ________ for the evaporation of water.

Accepted Answer

The answer of The sign (+ or -)of ΔH is...

Question 19

Without doing any calculations,determine whether the standard entropy change,ΔS° is positive or negative for each of the following reactions. reaction 1: S(s,rhombic)+ O2(g)→ SO2(g)
Reaction 2: 2 SO2(g)+ O2(g)→ 2 SO3(g)

Accepted Answer

A) ΔS° is positive for both reactions. 
B) ΔS° is positive for reaction 1 but negative for reaction 2. 
C) ΔS° is positive for reaction 2 but negative for reaction 1. 
D) ΔS° is negative for both reactions. 
A) ΔS° is positive for both reactions. 
B) ΔS° is positive for reaction 1 but negative for reaction 2. 
C) ΔS° is positive for reaction 2 but negative for reaction 1. 
D) ΔS° is negative for both reactions.

Question 20

If ΔG is small and positive,

Accepted Answer

A) the forward reaction is spontaneous and the system is far from equilibrium. 
B) the forward reaction is spontaneous and the system is near equilibrium. 
C) the reverse reaction is spontaneous and the system is far from equilibrium. 
D) the reverse reaction is spontaneous and the system is near equilibrium. 
A) the forward reaction is spontaneous and the system is far from equilibrium. 
B) the forward reaction is spontaneous and the system is near equilibrium. 
C) the reverse reaction is spontaneous and the system is far from equilibrium. 
D) the reverse reaction is spontaneous and the system is near equilibrium.

Exam 17: Thermodynamics: Entropy, free Energy, and Equilibrium

Under which of the following conditions would one mole of Ne have the highest entropy,S?

Which one of the following has the lowest standard molar entropy,S°,at 25°C?

Which statement is true about the formation of CaCO3(s)from CaO(s)and CO2(g)at 1.00 atm? CaO(s)+ CO2(g)→ CaCO3(s) ΔH° = -178.7 kJ and ΔS° = -150.4 J/K

The solubility of manganese(II)fluoride in water is 6.6 g/mL at 40°C and 4.8 g/L at 100°C.Based on these data,what is the sign of ΔH° and ΔS° for the process below? MnF2(s)⇌ Mn2+(aq)+ 2 F-(aq)

-According to the diagram above,

The synthesis of ethanol from ethylene and water proceeds using the following reaction. C2H4(g)+ H2O(l)C2H5OH(l)ΔGºrxn = -116.6 kJ/mol Determine the Gibbs free energy if the pressure of the vessel is 325 atm at 570 K.

Which statement is true concerning the standard states of F2(g)and C12H22O11(aq)?

For the following reaction find Kp at 25°C and indicate whether Kp should increase or decrease as the temperature rises. NH4HS(s)⇌ H2S(g)+ NH3(g)ΔH° = 83.47 kJ and ΔG° = 17.5 kJ at 25°C.

The following pictures represent three equilibrium mixtures for the interconversion of A,B,and C molecules (unshaded spheres)into X,Y,and Z molecules (shaded spheres),respectively.What is the sign of ΔG ° for each of the three reactions?

Consider the reaction 2A(g)⇌ A2(g).The following pictures represent two possible initial states and the equilibrium state of the system. -For initial state 1 what is the relationship between the reaction quotient,Qp,and the equilibrium constant,Kp?

-According to the diagram above,the forward reaction is

The standard molar entropy for Br2(g)is 245.46 J/(mol ∙ K)at 25°C.Given that ΔS° = 104.58 J/K for the dissociation of one mole of Br2(g)into Br(g)at 25°C,find the standard molar entropy for Br(g)at 25°C.

Standard molar entropies,S°,in J/Kmol,are given below each reactant and product in the reaction shown below.The standard entropy of reaction,ΔS°,for this reaction is ________ J/K. 2 SO2(g)+ O2(g)→ 2 SO3(g) 248.1 205.0 256.6

For the process CaCO3(calcite)→ CaCO3(aragonite)ΔH° = -0.21 kJ,ΔS° = -4.2 J/K Assuming that the surroundings can be considered a large heat reservoir at 25°C,calculate ΔSsurr and ΔStotal for the process at 25°C and 1 atm pressure.Is the process spontaneous at 25°C and 1 atm pressure?

Which of the three laws of thermodynamics states the criterion for spontaneity?

Which has the lowest entropy?

The sign (+ or -)of ΔH is ________ and the sign (+ or -)of ΔS is ________ for the evaporation of water.

Without doing any calculations,determine whether the standard entropy change,ΔS° is positive or negative for each of the following reactions. reaction 1: S(s,rhombic)+ O2(g)→ SO2(g) Reaction 2: 2 SO2(g)+ O2(g)→ 2 SO3(g)

If ΔG is small and positive,

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Which statement is true about the formation of CaCO₃(s)from CaO(s)and CO₂(g)at 1.00 atm? CaO(s)+ CO₂(g)→ CaCO₃(s) ΔH° = -178.7 kJ and ΔS° = -150.4 J/K

The solubility of manganese(II)fluoride in water is 6.6 g/mL at 40°C and 4.8 g/L at 100°C.Based on these data,what is the sign of ΔH° and ΔS° for the process below? MnF₂(s)⇌ Mn²⁺(aq)+ 2 F^-(aq)

The synthesis of ethanol from ethylene and water proceeds using the following reaction. C₂H₄(g)+ H₂O(l)C₂H₅OH(l)ΔGº_rxn= -116.6 kJ/mol Determine the Gibbs free energy if the pressure of the vessel is 325 atm at 570 K.

Which statement is true concerning the standard states of F₂(g)and C₁₂H₂₂O₁₁(aq)?

For the following reaction find K_p at 25°C and indicate whether K_p should increase or decrease as the temperature rises. NH₄HS(s)⇌ H₂S(g)+ NH₃(g)ΔH° = 83.47 kJ and ΔG° = 17.5 kJ at 25°C.

Consider the reaction 2A(g)⇌ A₂(g).The following pictures represent two possible initial states and the equilibrium state of the system. -For initial state 1 what is the relationship between the reaction quotient,Q_p,and the equilibrium constant,K_p?

The standard molar entropy for Br₂(g)is 245.46 J/(mol ∙ K)at 25°C.Given that ΔS° = 104.58 J/K for the dissociation of one mole of Br₂(g)into Br(g)at 25°C,find the standard molar entropy for Br(g)at 25°C.

Standard molar entropies,S°,in J/Kmol,are given below each reactant and product in the reaction shown below.The standard entropy of reaction,ΔS°,for this reaction is ________ J/K. 2 SO₂(g)+ O₂(g)→ 2 SO₃(g) 248.1 205.0 256.6

The sign (+ or -)of ΔH is and the sign (+ or -)of ΔS is for the evaporation of water.

Without doing any calculations,determine whether the standard entropy change,ΔS° is positive or negative for each of the following reactions. reaction 1: S(s,rhombic)+ O₂(g)→ SO₂(g) Reaction 2: 2 SO₂(g)+ O₂(g)→ 2 SO₃(g)