Deck 11: Liquids and Intermolecular Forces

Question 1

The predominant intermolecular force in (CH₃)₂NH is ________.

A)London dispersion forces
B)ion-dipole forces
C)ionic bonding
D)dipole-dipole forces
E)hydrogen bonding

Answer 1

hydrogen bonding

Question 2

Elemental iodine (I₂)is a solid at room temperature. What is the major attractive force that exists among different I₂ molecules in the solid?

A)London dispersion forces
B)dipole-dipole rejections
C)ionic-dipole interactions
D)covalent-ionic interactions
E)dipole-dipole attractions

Answer 2

London dispersion forces

Question 3

What intermolecular force is responsible for the fact that ice is less dense than liquid water?

A)London dispersion forces
B)dipole-dipole forces
C)ion-dipole forces
D)hydrogen bonding
E)ionic bonding

Answer 3

hydrogen bonding

Question 4

The intermolecular force(s)responsible for the fact that CH₄ has the lowest boiling point in the set CH₄, SiH₄, GeH₄, SnH₄ is/are ________.

A)hydrogen bonding
B)dipole-dipole interactions
C)London dispersion forces
D)mainly hydrogen bonding but also dipole-dipole interactions
E)mainly London-dispersion forces but also dipole-dipole interactions

Question 5

Which of the following has dispersion forces as its only intermolecular force?

A)CH₄
B)HCl
C)C₆H₁₃NH₂
D)NaCl
E)CH₃Cl

Question 6

Crystalline solids ________.

A)have their particles arranged randomly
B)have highly ordered structures
C)are usually very soft
D)exist only at high temperatures
E)exist only at very low temperatures

Question 7

Which one of the following substances will not have hydrogen bonding as one of its intermolecular forces?

A)
B)
C)
D)
E)

Question 8

Which statement is true about liquids but not true about solids?

A)They flow and are highly ordered.
B)They are highly ordered and not compressible.
C)They flow and are compressible.
D)They assume both the volume and the shape of their containers.
E)They flow and are not compressible.

Question 9

As a gaseous element condenses, the atoms become ________ and they have ________ attraction for one another.

A)more separated, more
B)more separated, less
C)closer together, more
D)closer together, less
E)larger, greater

Question 10

Hydrogen bonding is a special case of ________.

A)London-dispersion forces
B)ion-dipole attraction
C)dipole-dipole attractions
D)ion-ion interactions
E)none of the above

Question 11

The ease with which the charge distribution in a molecule can be distorted by an external electrical field is called the ________.

A)electronegativity
B)hydrogen bonding
C)polarizability
D)volatility
E)viscosity

Question 12

Together, liquids and solids constitute ________ phases of matter.

A)the compressible
B)the fluid
C)the condensed
D)all of the
E)the disordered

Question 13

When NaCl dissolves in water, aqueous Na⁺ and Cl^- ions result. The force of attraction that exists between Na⁺ and H₂O is called a(n)________ interaction.

A)dipole-dipole
B)ion-ion
C)hydrogen bonding
D)ion-dipole
E)London dispersion force

Question 14

________ are particularly polarizable.

A)Small nonpolar molecules
B)Small polar molecules
C)Large nonpolar molecules
D)Large polar molecules
E)Large molecules, regardless of their polarity,

Question 15

In liquids, the attractive intermolecular forces are ________.

A)very weak compared with kinetic energies of the molecules
B)strong enough to hold molecules relatively close together
C)strong enough to keep the molecules confined to vibrating about their fixed lattice points
D)not strong enough to keep molecules from moving past each other
E)strong enough to hold molecules relatively close together but not strong enough to keep molecules from moving past each other

Question 16

A gas is ________ and assumes ________ of its container, whereas a liquid is ________ and assumes ________ of its container.

A)compressible, the volume and shape, not compressible, the shape of a portion
B)compressible, the shape, not compressible, the volume and shape
C)compressible, the volume and shape, compressible, the volume
D)condensed, the volume and shape, condensed, the volume and shape
E)condensed, the shape, compressible, the volume and shape

Question 17

The strongest interparticle attractions exist between particles of a ________, and the weakest interparticle attractions exist between particles of a ________.

A)solid, liquid
B)solid, gas
C)liquid, gas
D)liquid, solid
E)gas, solid

Question 18

Which one of the following substances will have hydrogen bonding as one of its intermolecular forces?

A)
B)
C)
D)
E)

Question 19

Of the following substances, only ________ has London dispersion forces as the only intermolecular force.

A)CH₃OH
B)NH₃
C)H₂S
D)Kr
E)HCl

Question 20

In which of the following molecules is hydrogen bonding likely to be the most significant component of the total intermolecular forces?

A)CH₄
B)C₅H₁₁OH
C)C₆H₁₃NH₂
D)CH₃OH
E)CO₂

Question 21

What types of intermolecular forces exist between HI and H₂S?

A)dipole-dipole and ion-dipole
B)dispersion forces, dipole-dipole, and ion-dipole
C)dispersion forces, hydrogen bonding, dipole-dipole, and ion-dipole
D)dispersion forces and dipole-dipole
E)dispersion forces and ion-dipole

Question 22

Which of the following molecules has hydrogen bonding as its only intermolecular force?

A)HF
B)H₂O
C)C₆H₁₃NH₂
D)C₅H₁₁OH
E)None, all of the above exhibit dispersion forces.

Question 23

Based on the following information, which compound has the strongest intermolecular forces? Substance ΔH_vap (kJ/mol)
Argon (Ar)6.3
Benzene (C₆H₆)31.0
Ethanol (C₂H₅OH)39.3
Water (H₂O)40.8
Methane (CH₄)9.2

A)Argon
B)Benzene
C)Ethanol
D)Water
E)Methane

Question 24

C₁₂H₂₆ molecules are held together by ________.

A)ion-ion interactions
B)hydrogen bonding
C)ion-dipole interactions
D)dipole-dipole interactions
E)dispersion forces

Question 25

The shape of a liquid's meniscus is determined by ________.

A)the viscosity of the liquid
B)the type of material the container is made of
C)the relative magnitudes of cohesive forces in the liquid and adhesive forces between the liquid and its container
D)the amount of hydrogen bonding in the liquid
E)the volume of the liquid

Question 26

Large intermolecular forces in a substance are manifested by ________.

A)low vapor pressure
B)high boiling point
C)high heats of fusion and vaporization
D)high critical temperatures and pressures
E)all of the above

Question 27

What type(s)of intermolecular forces exist between PH₃ and CO₃^2-?

A)dispersion forces
B)dispersion forces and ion-dipole
C)dispersion forces, ion-dipole, and dipole-dipole
D)dispersion forces and dipole-dipole
E)dispersion forces, ion-dipole, dipole-dipole, and hydrogen bonds

Question 28

The phase changes B → C and D → E are not associated with temperature increases because the heat energy is used up to ________.

A)increase distances between molecules
B)break intramolecular bonds
C)rearrange atoms within molecules
D)increase the velocity of molecules
E)increase the density of the sample

Question 29

Which statements about viscosity are true? (i)Viscosity increases as temperature decreases.
(ii)Viscosity increases as molecular weight increases.
(iii)Viscosity increases as intermolecular forces increase.

A)(i)only
B)(ii)and (iii)
C)(i)and (iii)
D)none
E)all

Question 30

What type(s)of intermolecular forces exist between Br₂ and CCl₄?

A)dispersion forces
B)dispersion forces and ion-dipole
C)dispersion forces and dipole-dipole
D)dispersion forces, ion-dipole, and dipole-dipole
E)None. Since both are gases at room temperature, they do not interact with each other.

Question 31

Heat of sublimation can be approximated by adding together ________ and ________.

A)heat of fusion, heat of condensation
B)heat of fusion, heat of vaporization
C)heat of freezing (solidification), heat of condensation
D)heat of freezing (solidification), heat of vaporization
E)heat of deposition, heat of vaporization

Question 32

________ is the energy required to expand the surface area of a liquid by a unit amount of area.

A)Viscosity
B)Surface tension
C)Volatility
D)Meniscus
E)Capillary action

Question 33

Viscosity is ________.

A)the "skin" on a liquid surface caused by intermolecular attraction
B)the resistance to flow
C)the same as density
D)inversely proportional to molar mass
E)unaffected by temperature

Question 34

The property responsible for the "beading up" of water is ________.

A)density
B)viscosity
C)vapor pressure
D)surface tension
E)hydrogen bonding

Question 35

What types of intermolecular forces exist between NH₃ and H₂S?

A)dispersion forces and dipole-dipole forces
B)dispersion forces
C)dispersion forces and hydrogen bonds
D)dispersion forces, hydrogen bonds, and dipole-dipole forces
E)dispersion forces, hydrogen bonds, and ion-dipole forces

Question 36

Which of the following statements is false?

A)The absolute value of the heat of sublimation is equal to the absolute value of the heat of deposition.
B)The heat of sublimation is equal to the sum of the heat of vaporization and the heat of melting.
C)The heat of sublimation is equal to the sum of the heat of vaporization and the heat of freezing.
D)The absolute value of the heat of sublimation is equal to the absolute value of the sum of the heat of condensation and the heat of freezing.
E)The absolute value of the heat of deposition is equal to sum of the absolute value of the heat of vaporization and the absolute value of the heat of freezing.

Question 37

What types of intermolecular forces exist between NH₃ and HF?

A)dispersion forces and dipole-dipole forces
B)dispersion forces and hydrogen bonds
C)dispersion forces, dipole-dipole forces, and hydrogen bonds
D)dispersion forces
E)dispersion forces, hydrogen bonds, and ion-dipole forces

Question 38

How high a liquid will rise up a narrow tube as a result of capillary action depends on ________.

A)the magnitudes of cohesive forces in the liquid and adhesive forces between the liquid and the tube, and gravity
B)gravity alone
C)only the magnitude of adhesive forces between the liquid and the tube
D)the viscosity of the liquid
E)only the magnitude of cohesive forces in the liquid

Question 39

Which compound has the strongest intermolecular forces?

A)CBr₄
B)C₁₂H₂₆
C)CI₄
D)N₂
E)O₂

Question 40

Which of the following molecules has hydrogen bonding as its only intermolecular force?

A)NH₃
B)H₂O
C)C₃H₇OH
D)HOCH₂CH₂OH
E)None, all of the above exhibit dispersion forces.

Question 41

When the phase diagram for a substance has a solid-liquid phase boundary line that has a negative slope (leans to the left), the substance ________.

A)can go from solid to liquid, within a small temperature range, via the application of pressure
B)sublimes rather than melts under ordinary conditions
C)cannot go from solid to liquid by application of pressure at any temperature
D)cannot be liquefied above its triple point
E)melts rather than sublimes under ordinary conditions

Question 42

Volatility and vapor pressure are ________.

A)inversely proportional to one another
B)directly proportional to one another
C)not related
D)the same thing
E)both independent of temperature

Question 43

Which of the following is most likely to exhibit liquid-crystalline behavior?

A)CH₃CH₂-C(CH₃)₂-CH₂CH₃
B)CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₃
C)CH₃CH₂CH₂CH₂CH₂^-
D)
E)

Question 44

In general, the vapor pressure of a substance increases as ________ increases.

A)surface tension
B)molecular weight
C)hydrogen bonding
D)viscosity
E)temperature

Question 45

The vapor pressure of a liquid ________.

A)increases linearly with increasing temperature
B)increases nonlinearly with increasing temperature
C)decreases linearly with increasing temperature
D)decreases nonlinearly with increasing temperature
E)is totally unrelated to its molecular structure

Question 46

The vapor pressure of any substance at its normal boiling point is

A)1 Pa
B)1 torr
C)1 atm
D)equal to atmospheric pressure
E)equal to the vapor pressure of water

Question 47

Of the following, ________ should have the highest critical temperature.

A)CBr₄
B)CCl₄
C)CF₄
D)CH₄
E)H₂

Question 48

A substance that expands to fill its container yet has a density approaching that of a liquid, and that can behave as a solvent is called a(n)________.

A)plasma
B)gas
C)liquid
D)amorphous solid
E)supercritical fluid and gas

Question 49

The predominant intermolecular force in CaBr₂ is ________.

A)London-dispersion forces
B)ion-dipole forces
C)ionic bonding
D)dipole-dipole forces
E)hydrogen bonding

Question 50

The critical temperature and pressure of CS₂ are 279 °C and 78 atm, respectively. At temperatures above 279 °C and pressures above 78 atm, CS₂ can only occur as a ________.

A)solid
B)liquid
C)liquid and gas
D)gas
E)supercritical fluid

Question 51

On a phase diagram, the critical temperature is ________.

A)the temperature below which a gas cannot be liquefied
B)the temperature above which a gas cannot be liquefied
C)the temperature at which all three states are in equilibrium
D)the temperature required to melt a solid
E)the temperature required to cause sublimation of a solid

Question 52

On a phase diagram, the critical pressure is ________.

A)the pressure required to melt a solid
B)the pressure below which a substance is a solid at all temperatures
C)the pressure above which a substance is a liquid at all temperatures
D)the pressure at which a liquid changes to a gas
E)the pressure required to liquefy a gas at its critical temperature

Question 53

Of the following, ________ is an exothermic process.

A)melting
B)subliming
C)freezing
D)boiling
E)All of the above are exothermic.

Question 54

The slope of a plot of the natural log of the vapor pressure of a substance versus 1/T is ________.

A)ΔH_vap
B)-ΔH_vap
C)
D)-
E)

Question 55

A volatile liquid is one that ________.

A)is highly flammable
B)is highly viscous
C)is highly hydrogen-bonded
D)is highly cohesive
E)readily evaporates

Question 56

On a phase diagram, the melting point is the same as ________.

A)the triple point
B)the critical point
C)the freezing point
D)the boiling point
E)the vapor-pressure curve

Question 57

Which of the following characteristics would prevent liquid crystal behavior?

A)long axial structure
B)ionic configuration
C)carbon-carbon single bonds
D)double bonding
E)polar groups

Question 58

In the smectic A liquid-crystalline phase, ________.

A)the molecules are aligned along their long axes, with no ordering with respect to the ends of the molecules
B)the molecules are arranged in sheets, with their long axes parallel and their ends aligned as well
C)the molecules are aligned with their long axes tilted with respect to a line perpendicular to the plane in which the molecules are stacked
D)disk-shaped molecules are aligned through a stacking of the disks in layers
E)the molecules are oriented in a totally random fashion

Question 59

Some things take longer to cook at high altitudes than at low altitudes because ________.

A)water boils at a lower temperature at high altitude than at low altitude
B)water boils at a higher temperature at high altitude than at low altitude
C)heat isn't conducted as well in low density air
D)natural gas flames don't burn as hot at high altitudes
E)there is a higher moisture content in the air at high altitude

Question 60

The substance with the largest heat of vaporization is ________.

A)I₂
B)Br₂
C)Cl₂
D)F₂
E)O₂

Question 61

On the phase diagram shown above, the coordinates of point ________ correspond to the triple point.

A)A
B)B
C)C
D)D
E)E

Question 62

The normal boiling point of the substance with the phase diagram shown above is ________ °C.

A)10
B)20
C)30
D)40
E)50

Question 63

The phase diagram of a substance is shown above. The area labeled ________ indicates the solid phase for the substance.

A)w
B)x
C)y
D)z
E)y and z

Question 64

The heating curve shown was generated by measuring the heat flow and temperature of a solid as it was heated. The heat flow into the sample in the segment ________ will yield the value of the ΔH_fusion of this substance.

A)AB
B)BC
C)CD
D)DE
E)EF

Question 65

The heating curve shown was generated by measuring the heat flow and temperature for a solid as it was heated. The slope of the ________ segment corresponds to the heat capacity of the solid.

A)AB
B)BC
C)CD
D)DE
E)EF

Question 66

Molecules with only single bonds do not generally exhibit liquid-crystalline properties because ________.

A)molecules without multiple bonds lack the rigidity necessary for alignment
B)molecules without multiple bonds are too small to exhibit liquid-crystalline properties
C)molecules with only single bonds are gases
D)molecules with only single bonds are too big to exhibit liquid-crystalline properties
E)molecules without multiple bonds lack the flexibility necessary for alignment

Question 67

The heating curve shown was generated by measuring the heat flow and temperature for a solid as it was heated. The slope of the ________ segment corresponds to the heat capacity of the liquid of the substance.

A)AB
B)BC
C)CD
D)DE
E)EF

Question 68

The phase diagram of a substance is shown above. The area labeled ________ indicates the gas phase for the substance.

A)w
B)x
C)y
D)z
E)y and z

Question 69

The phase diagram of a substance is given above. The region that corresponds to the solid phase is ________.

A)w
B)x
C)y
D)z
E)x and y

Question 70

The normal melting point of the substance with the phase diagram shown above is ________ °C.

A)15
B)25
C)35
D)45
E)55

Question 71

In the ________ liquid crystalline phase, the component molecules exhibit only one dimensional ordering.

A)nematic
B)smectic A
C)smectic B
D)smectic C
E)cholesteric

Question 72

Based on molecular mass and dipole moment of the five compounds in the table below, which should have the highest boiling point?

A)CH₃CH₂CH₃
B)CH₃OCH₃
C)CH₃Cl
D)CH₃CHO
E)CH₃CN

Question 73

The heating curve shown was generated by measuring the heat flow and temperature of a solid as it was heated. The heat flow into the sample in the segment ________ will yield the value of the ΔH_vap of this substance.

A)AB
B)BC
C)CD
D)DE
E)EF

Question 74

On the phase diagram shown above, segment ________ corresponds to the conditions of temperature and pressure under which the solid and the gas of the substance are in equilibrium.

A)AB
B)AC
C)AD
D)CD
E)BC

Question 75

The heating curve shown was generated by measuring the heat flow and temperature for a solid as it was heated. The slope of the ________ segment corresponds to the heat capacity of the gas.

A)AB
B)BC
C)CD
D)DE
E)EF

Question 76

Cholesteric liquid crystals are colored because ________.

A)each molecule is a chromophore
B)of the slight twist between layers
C)of the large spacing between layers
D)of the large number of conjugated bonds
E)all of the molecules contain multiple benzene rings

Question 77

For a given substance that exhibits liquid-crystalline properties, the liquid-crystalline state exists ________.

A)at one particular temperature below the melting point of the solid
B)in a range of temperatures below the melting point of the solid
C)at one particular temperature above the melting point of the solid
D)in a range of temperatures above the melting point of the solid
E)in a range of temperatures from below the melting point to above the melting point

Question 78

For a given substance that exhibits liquid-crystalline properties, the transition from solid to liquid-crystal state occurs ________.

A)over a range of temperatures between the melting point of the solid and the boiling point of the liquid
B)at the melting point of the solid
C)over a range of temperatures that includes the melting point of the solid
D)at a well-defined temperature above the melting point of the solid
E)at a well-defined temperature below the melting point of the solid

Question 79

In the ________ liquid crystalline phase, the component molecules are aligned along their long axis and are arranged in layers with the molecules in each plane twisted slightly in relation to the molecules in the planes above and below.

A)nematic
B)smectic A
C)smectic B
D)smectic C
E)cholesteric

Question 80

On the phase diagram shown above, the coordinates of point ________ correspond to the critical temperature and pressure.

A)A
B)B
C)C
D)D
E)E