Question 1

Which of the following strong electrolytes has the most negative hydration enthalpy?

Accepted Answer

A)   NaCl
B)   KCl
C)   RbCl
D)   CsCl
E)   HClF) A) and E)
G) A) and D)

Question 2

Freon-113, C2Cl3F3, has an enthalpy of vaporization of 27.0 kJ/mol and a normal boiling point of 48.0 °C. What is the vapor pressure (in atm)  of Freon-113 at 22.0 °C? (R = 8.314 J/K⋅mol)

Accepted Answer

A)   0.21 atm
B)   0.35 atm
C)   0.41 atm
D)   0.46 atm
E)   4.4 atmF) D) and E)
G) C) and D)

Question 3

Which of the following is the slope of the line that illustrates the relationship between the natural logarithm of the vapor pressure of a gas and the reciprocal of its temperature (in kelvin) ?

Accepted Answer

A)    −RTΔvap H- \frac { R T } { \Delta _ { 	ext {vap } } H }−Δvap ​HRT​ 
B)    −R×Δvap H- R 	imes \Delta _ { 	ext {vap } } H−R×Δvap ​H 
C)   T
D)    −Δvap H- \Delta _ { 	ext {vap } } H−Δvap ​H 
E)    −Δvap HR- \frac { \Delta _ { 	ext {vap } } H } { R }−RΔvap ​H​F) C) and D)
G) A) and E)

Question 4

As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: HBr, NBr3, SBr2, and CBr4?

Accepted Answer

A)   HBr only
B)   CBr4 only
C)   HBr and SBr2
D)   NBr3 and CBr4
E)   HBr, NBr3, and SBr2F) C) and D)
G) None of the above E

Question 5

London dispersion forces are the only significant factor affecting boiling point for all the following except?

Accepted Answer

A)   Kr
B)   NH3
C)   CBr4
D)   Cl2
E)   CH4F) B) and D)
G) A) and C)

Question 6

Which of the following statements best describes what happens when a small amount of solid potassium chloride is dissolved in water?

Accepted Answer

A)   The heat from the warm water melts the solid, making it a liquid.
B)   Nothing happens, because potassium chloride is insoluble in water.
C)   The solid KCl breaks apart into separate K and Cl atoms by interacting with the water molecules.
D)   The water molecules surround each ion in the solid KCl, separating the K ions from the Cl ions.
E)   The solid undergoes a chemical change by reacting with the water.F) B) and C)
G) C) and D)

Question 7

The vapor pressure of a given liquid will increase if

Accepted Answer

A)   the liquid is moved to a container in which its surface area is very much larger.
B)   the volume of the liquid is increased.
C)   the temperature is increased.
D)   the volume of the vapor phase is increased.
E)   a more volatile liquid is added to the given liquid.F) B) and E)
G) B) and D)

Question 8

Arrange HF, HCl, and HBr in increasing order of their boiling point.

Accepted Answer

A)   HF 
B)   HF 
C)   HBr 
D)   HBr 
E)   HCl < HBr < HFF) A) and E)
G) All of the above E

Question 9

Which one of the following statements is false?

Accepted Answer

A)   All ions are hydrated in aqueous solution.
B)   All cations are hydrated in aqueous solution.
C)   All anions are hydrated in aqueous solution.
D)   Hydration is generally highly endothermic for ionic compounds.
E)   The heats of hydration of cations increases as their charge-to-radius ratios increase.F) None of the above
G) A) and B)

Question 10

Consider the following molecules: ethanol (CH3CH2OH) , acetic acid (CH3CO2H) , acetaldehyde (CH3CHO) , and dimethyl ether (CH3OCH3) . Which of these molecules is/are expected to form hydrogen bonds in the liquid or solid phase?

Accepted Answer

A)   Ethanol only
B)   Acetaldehyde only
C)   Ethanol and acetic acid
D)   Acetaldehyde and dimethyl ether
E)   Ethanol and dimethyl etherF) D) and E)
G) A) and E)

Question 11

For a particular liquid, raising its temperature from 331 K to 351 K causes its vapor pressure to double. What is the enthalpy of vaporization of this liquid? (R = 8.314 J/K · mol)

Accepted Answer

A)   34 kJ/mol
B)   288 kJ/mol
C)   2 kJ/mol
D)   244 kJ/mol
E)   115 kJ/molF) A) and B)
G) A) and C)

Question 12

Two important allotropes of phosphorus are white phosphorus and red phosphorus. White phosphorus, P4, has a melting point of 44.1 °C and spontaneously reacts with oxygen. Red phosphorus, a network solid, melts at 280 °C and is stable in air. Use your knowledge of intermolecular and intramolecular bonding to explain why these two forms of the same element have such different properties.

Accepted Answer

White phosphorus is a molecular solid composed of tetrahedral P₄ molecules. The P₄ molecules are held together by London dispersion forces. Red phosphorus is a network solid; all phosphorus atoms are connected through covalent bonds. It is easier to disrupt the weaker London dispersion forces of P₄ than it is to break the covalent bonds of red phosphorus.

Question 13

Ammonia (NH3)  is used as a refrigerant. At its boiling point of -33 °C, the standard enthalpy of vaporization of ammonia is 23.3 kJ/mol. How much heat is released when 50.0 g of ammonia is condensed at -33 °C?

Accepted Answer

A)   -0.466 kJ
B)   -7.94 kJ
C)   -36.6 × 103 kJ
D)   -68.4 kJ
E)   -1.17 × 103 kJF) All of the above
G) A) and C)

Question 14

Which of the following nonpolar molecules has the highest boiling point?

Accepted Answer

A)   N2
B)   C2H4
C)   F2
D)   O2
E)   CS2F) C) and E)
G) A) and E)

Question 15

A particular compound has an enthalpy of vaporization of 29600 J/mol. At 274 K it has a vapor pressure of 103 mmHg. What is its vapor pressure at 309 K? (R = 8.31 J/K·mol; 1 atm = 760 mmHg)

Accepted Answer

A)   98.6 mmHg
B)   241 mmHg
C)   23.6 mmHg
D)   449 mmHg
E)   107 mmHgF) C) and D)
G) All of the above

Question 16

As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: PH3, SO3, HCl, and CO2?

Accepted Answer

A)   PH3 only
B)   HCl only
C)   SO3 and CO2
D)   PH3 and HCl
E)   SO3, HCl, and CO2F) B) and E)
G) B) and D)

Question 17

In a certain mountain range, water boils at 93°C. What is the atmospheric pressure under these conditions? The enthalpy of vaporization of water at 100°C is 40.7 kJ/mol. (R = 8.314 J/K·mol; 1 atm = 760 mmHg)

Accepted Answer

A)   2040 mmHg
B)   278 mmHg
C)   591 mmHg
D)   977 mmHg
E)   283 mmHgF) A) and E)
G) A) and D)

Question 18

Equilibrium is established between a liquid and its vapor when

Accepted Answer

A)   the rate of evaporation equals the rate of condensation.
B)   equal masses exist in the liquid and gas phases.
C)   equal concentrations (in molarity)  exist in the liquid and gas phases.
D)   all the liquid has evaporated.
E)   the liquid ceases to evaporate and the gas ceases to condense.F) B) and C)
G) B) and D)

Question 19

When a glass tube with a small diameter is placed in water, the water rises in the tube. This is known as ________ action.

Accepted Answer

The answer of When a glass tube with a small...

Question 20

Above its critical temperature and pressure, a substance becomes a(n) ________ fluid.

Accepted Answer

The answer of Above its critical temperature and pressure, a...

Exam 12: Intermolecular Forces and Liquids

Which of the following strong electrolytes has the most negative hydration enthalpy?

Correct Answer
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Freon-113, C₂Cl₃F₃, has an enthalpy of vaporization of 27.0 kJ/mol and a normal boiling point of 48.0 °C. What is the vapor pressure (in atm) of Freon-113 at 22.0 °C? (R = 8.314 J/K⋅mol)

Correct Answer
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Which of the following is the slope of the line that illustrates the relationship between the natural logarithm of the vapor pressure of a gas and the reciprocal of its temperature (in kelvin) ?

Correct Answer
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As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: HBr, NBr₃, SBr₂, and CBr₄?

Correct Answer
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E

London dispersion forces are the only significant factor affecting boiling point for all the following except?

Correct Answer
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Which of the following statements best describes what happens when a small amount of solid potassium chloride is dissolved in water?

Correct Answer
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The vapor pressure of a given liquid will increase if

Correct Answer
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Arrange HF, HCl, and HBr in increasing order of their boiling point.

Correct Answer
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E

Which one of the following statements is false?

Correct Answer
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Consider the following molecules: ethanol (CH3CH2OH) , acetic acid (CH3CO2H) , acetaldehyde (CH3CHO) , and dimethyl ether (CH3OCH3) . Which of these molecules is/are expected to form hydrogen bonds in the liquid or solid phase?

Correct Answer
verified

For a particular liquid, raising its temperature from 331 K to 351 K causes its vapor pressure to double. What is the enthalpy of vaporization of this liquid? (R = 8.314 J/K · mol)

Correct Answer
verified

Ammonia (NH₃) is used as a refrigerant. At its boiling point of -33 °C, the standard enthalpy of vaporization of ammonia is 23.3 kJ/mol. How much heat is released when 50.0 g of ammonia is condensed at -33 °C?

Correct Answer
verified

Which of the following nonpolar molecules has the highest boiling point?

Correct Answer
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A particular compound has an enthalpy of vaporization of 29600 J/mol. At 274 K it has a vapor pressure of 103 mmHg. What is its vapor pressure at 309 K? (R = 8.31 J/K·mol; 1 atm = 760 mmHg)

Correct Answer
verified

As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: PH₃, SO₃, HCl, and CO₂?

Correct Answer
verified

In a certain mountain range, water boils at 93°C. What is the atmospheric pressure under these conditions? The enthalpy of vaporization of water at 100°C is 40.7 kJ/mol. (R = 8.314 J/K·mol; 1 atm = 760 mmHg)

Correct Answer
verified

Equilibrium is established between a liquid and its vapor when

Correct Answer
verified

When a glass tube with a small diameter is placed in water, the water rises in the tube. This is known as ________ action.

Correct Answer
verified

Above its critical temperature and pressure, a substance becomes a(n) ________ fluid.

Correct Answer
verified

Exam 12: Intermolecular Forces and Liquids

Which of the following strong electrolytes has the most negative hydration enthalpy?

Correct AnswerverifiedShow Answer

Freon-113, C2Cl3F3, has an enthalpy of vaporization of 27.0 kJ/mol and a normal boiling point of 48.0 °C. What is the vapor pressure (in atm) of Freon-113 at 22.0 °C? (R = 8.314 J/K⋅mol)

Correct AnswerverifiedShow Answer

Which of the following is the slope of the line that illustrates the relationship between the natural logarithm of the vapor pressure of a gas and the reciprocal of its temperature (in kelvin) ?

Correct AnswerverifiedShow Answer

As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: HBr, NBr3, SBr2, and CBr4?

Correct AnswerverifiedE

London dispersion forces are the only significant factor affecting boiling point for all the following except?

Correct AnswerverifiedShow Answer

Which of the following statements best describes what happens when a small amount of solid potassium chloride is dissolved in water?

Correct AnswerverifiedShow Answer

The vapor pressure of a given liquid will increase if

Correct AnswerverifiedShow Answer

Arrange HF, HCl, and HBr in increasing order of their boiling point.

Correct AnswerverifiedE

Which one of the following statements is false?

Correct AnswerverifiedShow Answer

Consider the following molecules: ethanol (CH3CH2OH) , acetic acid (CH3CO2H) , acetaldehyde (CH3CHO) , and dimethyl ether (CH3OCH3) . Which of these molecules is/are expected to form hydrogen bonds in the liquid or solid phase?

Correct AnswerverifiedShow Answer

For a particular liquid, raising its temperature from 331 K to 351 K causes its vapor pressure to double. What is the enthalpy of vaporization of this liquid? (R = 8.314 J/K · mol)

Correct AnswerverifiedShow Answer

Ammonia (NH3) is used as a refrigerant. At its boiling point of -33 °C, the standard enthalpy of vaporization of ammonia is 23.3 kJ/mol. How much heat is released when 50.0 g of ammonia is condensed at -33 °C?

Correct AnswerverifiedShow Answer

Which of the following nonpolar molecules has the highest boiling point?

Correct AnswerverifiedShow Answer

A particular compound has an enthalpy of vaporization of 29600 J/mol. At 274 K it has a vapor pressure of 103 mmHg. What is its vapor pressure at 309 K? (R = 8.31 J/K·mol; 1 atm = 760 mmHg)

Correct AnswerverifiedShow Answer

As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: PH3, SO3, HCl, and CO2?

Correct AnswerverifiedShow Answer

In a certain mountain range, water boils at 93°C. What is the atmospheric pressure under these conditions? The enthalpy of vaporization of water at 100°C is 40.7 kJ/mol. (R = 8.314 J/K·mol; 1 atm = 760 mmHg)

Correct AnswerverifiedShow Answer

Equilibrium is established between a liquid and its vapor when

Correct AnswerverifiedShow Answer

When a glass tube with a small diameter is placed in water, the water rises in the tube. This is known as ________ action.

Correct AnswerverifiedShow Answer

Above its critical temperature and pressure, a substance becomes a(n) ________ fluid.

Correct AnswerverifiedShow Answer

Correct Answer
verified

Freon-113, C₂Cl₃F₃, has an enthalpy of vaporization of 27.0 kJ/mol and a normal boiling point of 48.0 °C. What is the vapor pressure (in atm) of Freon-113 at 22.0 °C? (R = 8.314 J/K⋅mol)

Correct Answer
verified

Correct Answer
verified

As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: HBr, NBr₃, SBr₂, and CBr₄?

Correct Answer
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E

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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E

Correct Answer
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Correct Answer
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Correct Answer
verified

Ammonia (NH₃) is used as a refrigerant. At its boiling point of -33 °C, the standard enthalpy of vaporization of ammonia is 23.3 kJ/mol. How much heat is released when 50.0 g of ammonia is condensed at -33 °C?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

As pure molecular solids, which of the following exhibits dipole-dipole intermolecular forces: PH₃, SO₃, HCl, and CO₂?

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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