Question 1

Based on the phase diagram of a pure substance given below, what change of state occurs as the substance changes from point C to point D?

Accepted Answer

A)   The substance increases in temperature with a phase change from solid to liquid.
B)   The substance increases in temperature with a phase change from solid to vapor.
C)   The substance increases in temperature with a phase change from liquid to vapor.
D)   The substance increases in temperature but does not undergo a phase change.
E)   The substance increases in temperature and becomes a supercritical fluid.F) A) and D)
G) A) and C)

Question 2

Which is the correct equation for the molar heat of sublimation?

Accepted Answer

A)   ΔHsub = ΔHfus - ΔHvapVliq
B)   ΔHsub = ΔHdep + ΔHfus
C)   ΔUsub= ΔUfus + ΔUvap
D)   ΔHsub = ΔHfus - ΔHvap
E)   ΔHsub = ΔHfus + ΔHvapF) B) and E)
G) B) and D)

Question 3

How many phase changes are represented in the following heating curve of a pure substance?

Accepted Answer

A)   0
B)   1
C)   2
D)   3
E)   4F) B) and D)
G) D) and E)

Question 4

Identify the dominant (strongest) type of intermolecular force present in Cl2(l).

Accepted Answer

Question 5

The shape of the water-to-glass meniscus results from the strong adhesive forces between glass and water.

Accepted Answer

A) True 
 B)False

Question 6

Molecular crystals are held together by the intermolecular forces of dispersion and dipole-dipole forces and by hydrogen bonding.

Accepted Answer

A) True 
 B)False

Question 7

Which one of the following crystallizes in a metallic lattice?

Accepted Answer

A)   C
B)   NaMnO4
C)   K
D)   LiClO4
E)   K2Cr2O7F) A) and C)
G) D) and E)

Question 8

What is another name given to dispersion forces?

Accepted Answer

A)   ion-dipole interactions
B)   dipole-dipole interactions
C)   hydrogen bonding
D)   covalent forces
E)   London forcesF) B) and E)
G) A) and D)

Question 9

The energy required to increase the surface of a liquid per unit area is called the

Accepted Answer

A)   capillary action.
B)   surface tension.
C)   viscosity.
D)   cohesion.
E)   specific elasticity.F) C) and D)
G) B) and E)

Question 10

Which of the following properties indicates the presence of strong intermolecular forces in a liquid?

Accepted Answer

A)   a low heat of vaporization
B)   a low critical temperature
C)   a low vapor pressure
D)   a low boiling point
E)   a low melting pointF) C) and D)
G) A) and B) C

Question 11

________ is the name given to the phase change from a solid directly to a gas.

Accepted Answer

Sublimation

Question 12

What name is given to the curved surface of a liquid contained in a narrow tube?

Accepted Answer

A)   Surface tension
B)   Adhesion point
C)   Meniscus
D)   Capillary point
E)   Cohesion pointF) None of the above
G) C) and D)

Question 13

What is determined by the magnitude of intermolecular forces in a liquid and is a measure of a fluid's resistance to flow?

Accepted Answer

A)   Surface tension
B)   Adhesion
C)   Polarity
D)   Viscosity
E)   CohesionF) C) and E)
G) None of the above

Question 14

Based on the phase diagram of a pure substance given below, which statement is true?

Accepted Answer

A)   The solid phase has a lower density than the liquid phase.
B)   The triple point is at a higher temperature than the normal melting point.
C)   The substance changes from a solid to a liquid as one follows the line from C to D.
D)   The substance changes from a liquid to a gas as one follows the line from C to D.
E)   Point B represents the critical temperature and pressure for the substance.F) A) and E)
G) None of the above

Question 15

In a sample of hydrogen iodide, ________ are the most important intermolecular forces.

Accepted Answer

A)   dipole-dipole forces
B)   London dispersion forces
C)   hydrogen bonding
D)   covalent bonds
E)   polar covalent bondsF) B) and D)
G) B) and C)

Question 16

________ ________ are characterized by an instantaneous dipole.

Accepted Answer

London for...

Question 17

Liquid sodium can be used as a heat transfer fluid. Its vapor pressure is 40.0 torr at 633°C and 400.0 torr at 823°C. What is its heat of vaporization?

Accepted Answer

A)   43.4 kJ/mol
B)   52.5 kJ/mol
C)   70.6 kJ/mol
D)   1.00 × 102 kJ/mol
E)   3.64 kJ/molF) B) and E)
G) A) and E) D

Question 18

At a temperature of 27 K, neon condenses due to

Accepted Answer

A)   dipole-dipole forces.
B)   London dispersion forces.
C)   hydrogen bonding.
D)   covalent bonding.
E)   intramolecular forces.F) A) and E)
G) A) and D)

Question 19

What is defined as the number of atoms surrounding an atom in a crystal lattice and indicates how tightly the atoms are packed together?

Accepted Answer

A)   The unit cell
B)   The radius of the cubic cell
C)   The coordination number
D)   The area of the cubic cell
E)   The atoms themselvesF) A) and B)
G) B) and E)

Question 20

Based on the phase diagram of a pure substance given below, what is the significance of the point labeled B?

Accepted Answer

A)   It is the normal melting point.
B)   It is the triple point.
C)   It is the critical point.
D)   It is the normal sublimation point.
E)   It is the normal boiling point.F) B) and D)
G) None of the above

Exam 11: Intermolecular Forces and the Physical Properties of Liquids and Solids

Based on the phase diagram of a pure substance given below, what change of state occurs as the substance changes from point C to point D?

Correct AnswerverifiedShow Answer

Which is the correct equation for the molar heat of sublimation?

Correct AnswerverifiedShow Answer

How many phase changes are represented in the following heating curve of a pure substance?

Correct AnswerverifiedShow Answer

Identify the dominant (strongest) type of intermolecular force present in Cl2(l).

Correct AnswerverifiedShow Answer

The shape of the water-to-glass meniscus results from the strong adhesive forces between glass and water.

Correct AnswerverifiedShow Answer

Molecular crystals are held together by the intermolecular forces of dispersion and dipole-dipole forces and by hydrogen bonding.

Correct AnswerverifiedShow Answer

Which one of the following crystallizes in a metallic lattice?

Correct AnswerverifiedShow Answer

What is another name given to dispersion forces?

Correct AnswerverifiedShow Answer

The energy required to increase the surface of a liquid per unit area is called the

Correct AnswerverifiedShow Answer

Which of the following properties indicates the presence of strong intermolecular forces in a liquid?

Correct AnswerverifiedC

________ is the name given to the phase change from a solid directly to a gas.

Correct AnswerverifiedSublimation

What name is given to the curved surface of a liquid contained in a narrow tube?

Correct AnswerverifiedShow Answer

What is determined by the magnitude of intermolecular forces in a liquid and is a measure of a fluid's resistance to flow?

Correct AnswerverifiedShow Answer

Based on the phase diagram of a pure substance given below, which statement is true?

Correct AnswerverifiedShow Answer

In a sample of hydrogen iodide, ________ are the most important intermolecular forces.

Correct AnswerverifiedShow Answer

________ ________ are characterized by an instantaneous dipole.

Correct AnswerverifiedLondon for...View AnswerShow Answer

Liquid sodium can be used as a heat transfer fluid. Its vapor pressure is 40.0 torr at 633°C and 400.0 torr at 823°C. What is its heat of vaporization?

Correct AnswerverifiedD

At a temperature of 27 K, neon condenses due to

Correct AnswerverifiedShow Answer

What is defined as the number of atoms surrounding an atom in a crystal lattice and indicates how tightly the atoms are packed together?

Correct AnswerverifiedShow Answer

Based on the phase diagram of a pure substance given below, what is the significance of the point labeled B?

Correct AnswerverifiedShow Answer

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Identify the dominant (strongest) type of intermolecular force present in Cl₂(l).

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C

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Sublimation

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are characterized by an instantaneous dipole.

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London for...
View Answer

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D

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