Question 1

An oxygen molecule can have several different modes of motions. One type of motion is ________

Accepted Answer

A)  kinetic energy. 
B)  potential energy. 
C)  vibrational. 
D)  elastic. 
E)  Boltzmann. 
A)  kinetic energy. 
B)  potential energy. 
C)  vibrational. 
D)  elastic. 
E)  Boltzmann.

Question 2

The entropy of a NaCl crystal is ________

Accepted Answer

A)  an intensive property and a state function. 
B)  an intensive property and a path function. 
C)  an extensive property and a state function. 
D)  an extensive property and a path function. 
E)  not appropriately described in terms of an intensive property, an extensive property, a state function, or a path function. 
A)  an intensive property and a state function. 
B)  an intensive property and a path function. 
C)  an extensive property and a state function. 
D)  an extensive property and a path function. 
E)  not appropriately described in terms of an intensive property, an extensive property, a state function, or a path function.

Question 3

Alcohols for use as biofuels can be produced from glucose that is obtained from starch and cellulose in plants. Use the information in the table below to determine the free-energy change and whether or not this reaction is spontaneous at 78°C, which is the boiling point of an ethanol-water azeotrope.
C6H12O6(s) $\longrightarrow$ 2CH3CH2OH(l) + 2CO2(g) $$\begin{array} { | c | c | c | } 
\hline \text { Compound } & & \boldsymbol { S } ^ { \circ } \
& \Delta \boldsymbol { H } _ { \mathbf { f } } ^ { \circ } & { [ \mathbf { J } / ( \mathbf { m o l } \cdot \mathbf { K } ) ] } \
\hline \text { Glucose } ( s ) & ( \mathbf { k J } / \mathbf { m o l } ) & 212 \
\hline \text { Ethanol } ( l ) & - 1,274 & 161 \
\hline \text { Carbon dioxide } ( g ) & - 278 & 214 \
\hline
\end{array}$$

Accepted Answer

A)  -6 kJ, spontaneous 
B)  +76 kJ, not spontaneous 
C)  -76 kJ, spontaneous 
D)  -258 kJ, not spontaneous 
E)  -258 kJ, spontaneous 
A)  -6 kJ, spontaneous 
B)  +76 kJ, not spontaneous 
C)  -76 kJ, spontaneous 
D)  -258 kJ, not spontaneous 
E)  -258 kJ, spontaneous

Question 4

The enthalpy of fusion for benzene (C6H6) is 127.40 kJ/kg, and its melting point is 5.5°C. What is the entropy change when 1 mole of benzene melts at 5.5°C?

Accepted Answer

A)  9.95 kJ/K 
B)  35.7 J/K 
C)  1,809 J/K 
D)  1.81 J/K 
E)  127.40 kJ/K 
A)  9.95 kJ/K 
B)  35.7 J/K 
C)  1,809 J/K 
D)  1.81 J/K 
E)  127.40 kJ/K

Question 5

Indicate which of the following has the smallest standard molar entropy (S°).

Accepted Answer

A)  CH4(g) 
B)  CH3CH2OH(l) 
C)  H2O(s) 
D)  Na(s) 
E)  He(g) 
A)  CH4(g) 
B)  CH3CH2OH(l) 
C)  H2O(s) 
D)  Na(s) 
E)  He(g)

Question 6

What are the signs of$\Delta$H°, $\Delta$S°, and $\Delta$G° for the conversion of liquid water to ice at 10°C and 1 atm? Briefly explain each answer.

Accepted Answer

@#LAT-DLM&H° is negative, because heat m

Question 7

Which of the following processes will lead to a decrease in the entropy of the system?

Accepted Answer

A)  Salt crystals dissolve in water. 
B)  Air escapes from a hole in a balloon. 
C)  Iron and oxygen react to form rust. 
D)  Ice melts in your hand. 
E)  None of these leads to a negative change in the entropy of the system, because they are all spontaneous. 
A)  Salt crystals dissolve in water. 
B)  Air escapes from a hole in a balloon. 
C)  Iron and oxygen react to form rust. 
D)  Ice melts in your hand. 
E)  None of these leads to a negative change in the entropy of the system, because they are all spontaneous.

Question 8

The change in standard molar entropy, $\Delta$S$\degree$ for the following reaction is 494.6 J/mol . K at 25$\degree$C.
2KClO3(s) $\leftrightarrow$2KCl(s) + 3O2(g)
What is the standard molar entropy of O2(g) at 25$\degree$C?
S°(KClO3, s)
= 143.1 J/mol . K
S°(KCl, s)
= 82.6 J/mol . K

Accepted Answer

Question 9

According to the second law of thermodynamics, the change in the entropy of the universe ($\Delta$Suniv) during a spontaneous reaction is ________

Accepted Answer

A)  zero. 
B)  negative. 
C)  positive. 
D)  less than the change in entropy of the system ($\Delta$Ssys). 
E)  greater than the change in entropy of the system ($\Delta$Ssys). 
A)  zero. 
B)  negative. 
C)  positive. 
D)  less than the change in entropy of the system ($\Delta$Ssys). 
E)  greater than the change in entropy of the system ($\Delta$Ssys).

Question 10

At body temperature, many proteins have a well-defined structure that is essential to their
Function. However, as the temperature is raised, the structure changes and the protein is no longer functional. This process is referred to as protein denaturation. What can be deduced from this information about the signs of the enthalpy and entropy changes for denaturation?

Accepted Answer

A) ($\Delta$H > 0 and$\Delta$S > 0) B) ($\Delta$H > 0 and $\Delta$S 0) D) ($\Delta$H < 0 and $\Delta$S < 0) E) There is insufficient information to deduce anything about the signs of $\Delta$H and $\Delta$S. A) ($\Delta$H > 0 and$\Delta$S > 0) B) ($\Delta$H > 0 and $\Delta$S 0) D) ($\Delta$H < 0 and $\Delta$S < 0) E) There is insufficient information to deduce anything about the signs of $\Delta$H and $\Delta$S.

Question 11

NO gas is converted to NO2 gas according to the following reaction:
NO(g) + $$\frac { 1 } { 2 }$$ O2(g) $\rightarrow$ NO2(g)
What is the standard entropy change when 0.5 mol of NO gas reacts with 0.5 mol of O2 gas? $$\begin{array} { l c } 
\text { Substance } & \boldsymbol { S } ^ { \circ } ( \mathbf { J } / \mathbf { m o l } \cdot \mathbf { K } ) \
\mathrm { NO } ( g ) & 210.7 \
\mathrm { O } _ { 2 } ( g ) & 205.0 \
\mathrm { NO } _ { 2 } ( g ) & 240.0
\end{array}$$

Accepted Answer

A)  -36.6 J/K 
B)  -175.7 J/K 
C)  -83.4 J/K 
D)  +83.4 J/K 
E)  +36.6 J/K 
A)  -36.6 J/K 
B)  -175.7 J/K 
C)  -83.4 J/K 
D)  +83.4 J/K 
E)  +36.6 J/K

Question 12

Determine the value of $\Delta$G° for the reaction
2NO2(g) $\leftrightarrow$N2O4(g)
Given $ \begin{array}{lcr} 
Substance&&S^{\circ}(\mathrm{J} /(\mathbf{m o l} \cdot \mathbf{K}))\
& \Delta \boldsymbol{H}_{\mathbf{f}}^{\circ} & \ & (\mathbf{k J} / \mathbf{m o l}) & \ \mathrm{NO}_{2}(g) & 33.2 & 240.0 \ \mathrm{~N}_{2} \mathrm{O}_{4}(g) & 9.2 & 304.2\end{array} $

Accepted Answer

A)  -4.8 kJ 
B)  +4.8 kJ 
C)  +52.3 kJ 
D)  -52.3 kJ 
E)  -43 kJ 
A)  -4.8 kJ 
B)  +4.8 kJ 
C)  +52.3 kJ 
D)  -52.3 kJ 
E)  -43 kJ

Question 13

Which of the following statements is/are correct? A large equilibrium constant means that ________
I. the standard free-energy change for the reaction is large and negative.
II. the standard free-energy change for the reaction is large and positive.
III. the reaction greatly favors formation of the products.
IV. only a small amount of product is produced at equilibrium.

Accepted Answer

A)  I only 
B)  II only 
C)  both I and III 
D)  both II and IV 
E)  both II and III 
A)  I only 
B)  II only 
C)  both I and III 
D)  both II and IV 
E)  both II and III

Question 14

$\Delta$Ssys can be directly related to the heat, q. Which of statements A-D is not true regarding this relationship? If all are true, select E.

Accepted Answer

A)  ($\Delta$Ssys can always be determined from the heat transferred during the actual process.) 
B)  For a reversible spontaneous endothermic process, both q and $\Delta$Ssys will be positive. 
C)  The more heat that is transferred, the larger the magnitude of the entropy change. 
D)  The higher the temperature at which heat is transferred, the lower the entropy change. 
E)  All of the above are true. 
A)  ($\Delta$Ssys can always be determined from the heat transferred during the actual process.) 
B)  For a reversible spontaneous endothermic process, both q and $\Delta$Ssys will be positive. 
C)  The more heat that is transferred, the larger the magnitude of the entropy change. 
D)  The higher the temperature at which heat is transferred, the lower the entropy change. 
E)  All of the above are true.

Question 15

Nitrogen monoxide molecules can react to form dinitrogen oxide and nitrogen dioxide. Determine the equilibrium constant for this reaction under standard conditions from the following data and note whether the reaction is product-favored or reactant-favored.
$\Delta$G°(NO, g) = 86.6 kJ/mol
$\Delta$G°(N2O, g) = 104.2 kJ/mol
$\Delta$G°(NO2, g) = 51.3 kJ/mol

Accepted Answer

K = 1.9 *1

Question 16

What is the overall standard free-energy change for the following two reactions?
A + B $\rightarrow$ C 
$\Delta$GS1U1B1 S1U1B0 S1U1P1°S1S1P0  S1U1B1rxnS1U1B0S1U1B1 S1U1B0= $\Delta$GS1U1B11S1U1B0
C + D $\rightarrow$ E 
$\Delta$G S1U1P1°S1S1P0 S1U1B1rxnS1U1B0= $\Delta$GS1U1B12S1U1B0

Accepted Answer

A)  ($\Delta$GS1U1B11S1U1B0 + $\Delta$GS1U1B12S1U1B0) 
B)  ($\Delta$GS1U1B11S1U1B0 - $\Delta$GS1U1B12S1U1B0) 
C)  ($\Delta$GS1U1B12S1U1B0 - $\Delta$GS1U1B11S1U1B0) 
D) ($\Delta$GS1U1B11S1U1B0$\Delta$GS1U1B12S1U1B0) 
E) ($\Delta$GS1U1B11S1U1B0/$\Delta$GS1U1B12S1U1B0) 
A)  ($\Delta$GS1U1B11S1U1B0 + $\Delta$GS1U1B12S1U1B0) 
B)  ($\Delta$GS1U1B11S1U1B0 - $\Delta$GS1U1B12S1U1B0) 
C)  ($\Delta$GS1U1B12S1U1B0 - $\Delta$GS1U1B11S1U1B0) 
D) ($\Delta$GS1U1B11S1U1B0$\Delta$GS1U1B12S1U1B0) 
E) ($\Delta$GS1U1B11S1U1B0/$\Delta$GS1U1B12S1U1B0)

Question 17

Determine $\Delta$S $$\begin{array} { l } 
\circ\
\mathrm { rxn }
\end{array}$$ for H2(g) + I2(g)$\leftrightarrow$  2HI(g) given the following information: $$\begin{array} { l c } 
\text { Substance } & \mathbf { S } ^ { \circ } ( \mathbf { J } / \mathbf { m o l } \cdot \mathbf { K } ) \
\mathrm { H } _ { 2 } ( g ) & 130.58 \
\mathrm { I } _ { 2 } ( g ) & 116.73 \
\mathrm { HI } ( g ) & 206.3
\end{array}$$

Accepted Answer

A)  -41.10 J/K 
B)  -165.29 J/K 
C)  +398.75 J/K 
D)  +165.29 J/K 
E)  +41.10 J/K 
A)  -41.10 J/K 
B)  -165.29 J/K 
C)  +398.75 J/K 
D)  +165.29 J/K 
E)  +41.10 J/K

Question 18

In a spontaneous process, which of the following always increases?

Accepted Answer

A)  the entropy of the system 
B)  the entropy of the surroundings 
C)  the entropy of the universe 
D)  the entropy of the system and the universe 
E)  the entropy of the system, the surroundings, and the universe 
A)  the entropy of the system 
B)  the entropy of the surroundings 
C)  the entropy of the universe 
D)  the entropy of the system and the universe 
E)  the entropy of the system, the surroundings, and the universe

Question 19

The entropy of fusion for ice at 0°C and 1 atm is 22 J/mol .K. How many joules of heat are required to melt a typical ice cube at 0°C and 1 atm? Assume an ice cube is about 1 oz or 28
g.

Accepted Answer

The answer of The entropy of fusion for ice at...

Question 20

Which statement about the reaction below, where en = ethylenediamine (H2NCH2CH2NH2), is not correct?
Cr(NH3)63+ + 3en$\leftrightarrow$Cr(en)33+ + 6NH3

Accepted Answer

A)  The reaction is product-favored because the entropy of the system increases. 
B)  The Lewis basicity of the amino groups in en is comparable to that of the ammonia molecules. 
C)  The reaction is reactant-favored because the concentration of ammonia on the right side is higher than the concentration of en on the left side. 
D)  The reaction enthalpy is small because the Cr-NH3 and Cr-en bond strengths are very similar. 
E)  Both Cr(NH3)63+ and Cr(en)33+ have an octahedral coordination geometry and a coordination number of 6. 
A)  The reaction is product-favored because the entropy of the system increases. 
B)  The Lewis basicity of the amino groups in en is comparable to that of the ammonia molecules. 
C)  The reaction is reactant-favored because the concentration of ammonia on the right side is higher than the concentration of en on the left side. 
D)  The reaction enthalpy is small because the Cr-NH3 and Cr-en bond strengths are very similar. 
E)  Both Cr(NH3)63+ and Cr(en)33+ have an octahedral coordination geometry and a coordination number of 6.

An oxygen molecule can have several different modes of motions. One type of motion is ________

The entropy of a NaCl crystal is ________

The enthalpy of fusion for benzene (C₆H₆) is 127.40 kJ/kg, and its melting point is 5.5°C. What is the entropy change when 1 mole of benzene melts at 5.5°C?

Indicate which of the following has the smallest standard molar entropy (S°).

What are the signs of $\Delta$ H°, $\Delta$ S°, and $\Delta$ G° for the conversion of liquid water to ice at 10°C and 1 atm? Briefly explain each answer.

Which of the following processes will lead to a decrease in the entropy of the system?

The change in standard molar entropy, $\Delta$ S $\degree$ for the following reaction is 494.6 J/mol . K at 25 $\degree$ C. 2KClO₃(s) $\leftrightarrow$ 2KCl(s) + 3O₂(g) What is the standard molar entropy of O₂(g) at 25 $\degree$ C? S°(KClO₃, s) = 143.1 J/mol . K S°(KCl, s) = 82.6 J/mol . K

According to the second law of thermodynamics, the change in the entropy of the universe ( $\Delta$ S_univ) during a spontaneous reaction is ________

NO gas is converted to NO₂ gas according to the following reaction: NO(g) + $\frac { 1 } { 2 }$ O₂(g) $\rightarrow$ NO₂(g) What is the standard entropy change when 0.5 mol of NO gas reacts with 0.5 mol of O₂ gas? Substance (/\cdot) (g) 210.7 (g) 205.0 (g) 240.0

Determine the value of $\Delta$ G° for the reaction 2NO₂(g) $\leftrightarrow$ N₂O₄(g) Given Substance (/(\cdot)) \Delta (/) (g) 33.2 240.0 (g) 9.2 304.2

$\Delta$ S_sys can be directly related to the heat, q. Which of statements A-D is not true regarding this relationship? If all are true, select E.

What is the overall standard free-energy change for the following two reactions? A + B $\rightarrow$ C $\Delta$ G ^° _rxn= $\Delta$ G₁ C + D $\rightarrow$ E $\Delta$ G ^° _rxn= $\Delta$ G₂

Determine $\Delta$ S \circ for H₂(g) + I₂(g) $\leftrightarrow$ 2HI(g) given the following information: Substance (/\cdot) (g) 130.58 (g) 116.73 (g) 206.3

In a spontaneous process, which of the following always increases?

The entropy of fusion for ice at 0°C and 1 atm is 22 J/mol .K. How many joules of heat are required to melt a typical ice cube at 0°C and 1 atm? Assume an ice cube is about 1 oz or 28 g.

Which statement about the reaction below, where en = ethylenediamine (H₂NCH₂CH₂NH₂), is not correct? Cr(NH₃)₆³⁺ + 3en $\leftrightarrow$ Cr(en)₃³⁺ + 6NH₃

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: the Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Structures and Applications

Organic Chemistry: Fuels, Pharmaceuticals, Materials, and Life

Chemical Kinetics: Reactions in the Air We Breathe

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acid-Base and Solubility Equilibria: Reactions in Soil and Water

Metal Ions: Colorful and Essential

Electrochemistry: the Quest for Clean Energy

Biochemistry: the Compounds of Life

Nuclear Chemistry: Applications to Energy and Medicine

Life and the Periodic Table

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Exam 18: Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

An oxygen molecule can have several different modes of motions. One type of motion is ________

The entropy of a NaCl crystal is ________

The enthalpy of fusion for benzene (C6H6) is 127.40 kJ/kg, and its melting point is 5.5°C. What is the entropy change when 1 mole of benzene melts at 5.5°C?

Indicate which of the following has the smallest standard molar entropy (S°).

What are the signs of Δ\DeltaΔ H°, Δ\DeltaΔ S°, and Δ\DeltaΔ G° for the conversion of liquid water to ice at 10°C and 1 atm? Briefly explain each answer.

Which of the following processes will lead to a decrease in the entropy of the system?

According to the second law of thermodynamics, the change in the entropy of the universe ( Δ\DeltaΔ Suniv) during a spontaneous reaction is ________

NO gas is converted to NO2 gas according to the following reaction: NO(g) + 12\frac { 1 } { 2 }21​ O2(g) →\rightarrow→ NO2(g) What is the standard entropy change when 0.5 mol of NO gas reacts with 0.5 mol of O2 gas? Substance (/\cdot) (g) 210.7 (g) 205.0 (g) 240.0

Determine the value of Δ\DeltaΔ G° for the reaction 2NO2(g) ↔\leftrightarrow↔ N2O4(g) Given Substance (/(\cdot)) \Delta (/) (g) 33.2 240.0 (g) 9.2 304.2

Δ\DeltaΔ Ssys can be directly related to the heat, q. Which of statements A-D is not true regarding this relationship? If all are true, select E.

What is the overall standard free-energy change for the following two reactions? A + B →\rightarrow→ C Δ\DeltaΔ G ° rxn = Δ\DeltaΔ G1 C + D →\rightarrow→ E Δ\DeltaΔ G ° rxn= Δ\DeltaΔ G2

Determine Δ\DeltaΔ S \circ for H2(g) + I2(g) ↔\leftrightarrow↔ 2HI(g) given the following information: Substance (/\cdot) (g) 130.58 (g) 116.73 (g) 206.3

In a spontaneous process, which of the following always increases?

The entropy of fusion for ice at 0°C and 1 atm is 22 J/mol .K. How many joules of heat are required to melt a typical ice cube at 0°C and 1 atm? Assume an ice cube is about 1 oz or 28 g.

Which statement about the reaction below, where en = ethylenediamine (H2NCH2CH2NH2), is not correct? Cr(NH3)63+ + 3en ↔\leftrightarrow↔ Cr(en)33+ + 6NH3

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: the Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Structures and Applications

Organic Chemistry: Fuels, Pharmaceuticals, Materials, and Life

Chemical Kinetics: Reactions in the Air We Breathe

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acid-Base and Solubility Equilibria: Reactions in Soil and Water

Metal Ions: Colorful and Essential

Electrochemistry: the Quest for Clean Energy

Biochemistry: the Compounds of Life

Nuclear Chemistry: Applications to Energy and Medicine

Life and the Periodic Table

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The enthalpy of fusion for benzene (C₆H₆) is 127.40 kJ/kg, and its melting point is 5.5°C. What is the entropy change when 1 mole of benzene melts at 5.5°C?

What are the signs of $\Delta$ H°, $\Delta$ S°, and $\Delta$ G° for the conversion of liquid water to ice at 10°C and 1 atm? Briefly explain each answer.

According to the second law of thermodynamics, the change in the entropy of the universe ( $\Delta$ S_univ) during a spontaneous reaction is ________

NO gas is converted to NO₂ gas according to the following reaction: NO(g) + $\frac { 1 } { 2 }$ O₂(g) $\rightarrow$ NO₂(g) What is the standard entropy change when 0.5 mol of NO gas reacts with 0.5 mol of O₂ gas? Substance (/\cdot) (g) 210.7 (g) 205.0 (g) 240.0

Determine the value of $\Delta$ G° for the reaction 2NO₂(g) $\leftrightarrow$ N₂O₄(g) Given Substance (/(\cdot)) \Delta (/) (g) 33.2 240.0 (g) 9.2 304.2

$\Delta$ S_sys can be directly related to the heat, q. Which of statements A-D is not true regarding this relationship? If all are true, select E.

What is the overall standard free-energy change for the following two reactions? A + B $\rightarrow$ C $\Delta$ G ^° _rxn= $\Delta$ G₁ C + D $\rightarrow$ E $\Delta$ G ^° _rxn= $\Delta$ G₂

Determine $\Delta$ S \circ for H₂(g) + I₂(g) $\leftrightarrow$ 2HI(g) given the following information: Substance (/\cdot) (g) 130.58 (g) 116.73 (g) 206.3

Which statement about the reaction below, where en = ethylenediamine (H₂NCH₂CH₂NH₂), is not correct? Cr(NH₃)₆³⁺ + 3en $\leftrightarrow$ Cr(en)₃³⁺ + 6NH₃