Deck 11: Intermolecular Forces, Liquids, and Solids

Question 1

CsCl crystallizes in a unit cell that contains a Cs⁺ ion at the center of a cube and a Cl^- ion at each corner. The unit cell of CsCl is .

A) amorphous
B) primitive cubic
C) close packed
D) body- centered cubic
E) face- centered cubic

Answer 1

primitive cubic

Question 2

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

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

Answer 2

Surface tension

Question 3

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) (i) and (iii)
C) (ii) and (iii)
D) none
E) all

Answer 3

all

Question 4

Ethanol (C₂H₅OH) melts at - 114°C. The enthalpy of fusion is 5.02 kJ/mol. The specific heats of solid and liquid ethanol are 0.97 J/g- K and 2.3 J/g- K, respectively. How much heat (kJ) is needed to convert 25.0 g of solid ethanol at - 135°C to liquid ethanol at - 50°C?

A) 207.3
B) 9.21
C) - 12.7
D) 6.91
E) 4192

Question 5

Based on the figure above, the boiling point of diethyl ether under an external pressure of 1.32 atm is °C.

A) 20
B) 0
C) 10
D) 30
E) 40

Question 6

What fraction of the volume of each corner atom is actually within the volume of a face- centered cubic unit cell?

A) 1
B)
C)
D)
E)

Question 7

CsCl crystallizes in a unit cell that contains the Cs⁺ ion at the center of a cube that has a Cl^- at each corner. Each unit cell contains Cs⁺ ions and Cl^- , ions, respectively.

A) 1 and 8
B) 2 and 1
C) 1 and 1
D) 2 and 4
E) 2 and 2

Question 8

C₁₂ H₂₆ molecules are held together by .

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

Question 9

The phase diagram of a substance is given above. This substance is a at 25°C and 1.0 atm.

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

Question 10

Based on the figure above, the boiling point of ethyl alcohol under an external pressure of 0.0724 atm is °C.

A) 60
B) 80
C) 40
D) 70
E) 20

Question 11

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

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

Question 12

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

Question 13

What is the predominant intermolecular force in CBr₄?

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

Question 14

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

A)

B)

C)
D)

E)

Question 15

Which one of the following exhibits dipole- dipole attraction between molecules?

A) XeF₄
B) BCl₃
C) Cl₂
D) CO₂
E) AsH₃

Question 16

What portion of the volume of each atom or ion on the face of a unit cell is actually within the unit cell?

A) 3/4
B) 1/4
C) 1/2
D) all of it
E) none of it

Question 17

Hydrogen bonding is a special case of _ .

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

Question 18

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

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

Question 19

The vapor pressure of a liquid _.

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

Question 20

The predominant intermolecular force in CaBr₂ is _ .

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

Question 21

Metallic solids do not exhibit .

A) extreme brittleness
B) variable hardness
C) excellent thermal conductivity
D) variable melting point
E) excellent electrical conductivity

Question 22

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

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

Question 23

An ionic solid, NaCl (s), dissolves in water because of the .

A) relatively low melting point
B) strong coulombic interactions between oppositely charged ions
C) 1:
1 ratio of ions in the unit cell
D) simple face- centered cubic unit cell type it forms
E) relatively low lattice energy due to small charges of Na⁺ and Cl^- ions

Question 24

Large intermolecular forces in a substance are manifested by .

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

Question 25

On a phase diagram, the critical pressure is .

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

Question 26

Consider the following statements about crystalline solids:
(i) Molecules or atoms in molecular solids are held together via intermolecular forces.
(ii) Metallic solids have atoms in the points of the crystal lattice.
(iii) Ionic solids have formula units in the point of the crystal lattice.
(iv) Atoms in covalent- network solids are connected via a network of covalent bonds.
Which of the statements is false?

A) (i)
B) (ii)
C) (iii)
D) (iv)
E) none

Question 27

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

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

Question 28

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

Question 29

Volatility and vapor pressure are .

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

Question 30

Heat of sublimation can be approximated by adding together and .

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

Question 31

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

Question 32

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

Question 33

Based on the figure above, the boiling point of water under an external pressure of 0.316 atm atm is
__________°C.

A) 80
B) 90
C) 70
D) 60
E) 40

Question 34

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

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

Question 35

Crystalline solids .

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

Question 36

A volatile liquid is one that .

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

Question 37

The fluorocarbon C₂Cl₃F₃ has a normal boiling point of 47.6°C. The specific heats of C₂Cl₃F₃ (l) and C₂Cl₃F₃(g) are 0.91 J/g- K and 0.67 J/g- K, respectively. The heat of vaporization of the compound is 27.49 kJ/mol. The heat required to convert 50.0 g of the compound from the liquid at 5.0°C to the gas at 80.0°C is kJ.

A) 1454
B) 10.36
C) 30.51
D) 3031
E) 8.19

Question 38

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

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

Question 39

The unit cell with all sides the same length and all angles equal to 90° that has lattice points only at the corners is called .

A) primitive cubic
B) spherical cubic
C) face- centered cubic
D) monoclinic
E) body- centered cubic

Question 40

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

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

Question 41

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

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

Question 42

Viscosity is .

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

Question 43

Together, liquids and solids constitute _ phases of matter.

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

Question 44

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

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

Question 45

A solid has a very high melting point, great hardness, and poor electrical conduction. This is a(n)
Solid.

A) metallic and covalent network
B) covalent network
C) molecular
D) metallic
E) ionic

Question 46

Crystalline solids differ from amorphous solids in that crystalline solids have .

A) atoms, molecules, or ions that are close together
B) much larger atoms, molecules, or ions
C) no orderly structure
D) a long- range repeating pattern of atoms, molecules, or ions
E) appreciable intermolecular attractive forces

Question 47

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

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

Question 48

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

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

Question 49

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

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

Question 50

In liquids, the attractive intermolecular forces are .

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

Question 51

are particularly polarizable.

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

Question 52

As a solid element melts, the atoms become and they have _ attraction for one another.

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

Question 53

Which of the following is not an existing or a potential application of the supercritical carbon dioxide?

A) isolation of the flavor components of herbs and spices
B) extraction of essential flavor elements from hops for use in brewing
C) extraction of caffeine from coffee beans
D) use as a solvent in dry cleaning
E) use as a coolant in refrigeration

Question 54

The enthalpy change for converting 1.00 mol of ice at - 50.0°C to water at 70.0°C is kJ. The specific heats of ice, water, and steam are 2.09 J/g- K, 4.18 J/g- K, and 1.84 J/g- K, respectively. For H₂O, OH_fus = 6.01 kJ/mol, and OH_vap = 40.67 kJ/mol

A) 12.28
B) 13.16
C) 6.41
D) 9.40
E) 7154

Question 55

The enthalpy change for converting 10.0 g of ice at - 25.0°C to water at 80.0°C is kJ. The specific heats of ice, water, and steam are 2.09 J/g- K, 4.18 J/g- K, and 1.84 J/g- K, respectively. For H₂O, OH_fus = 6.01 kJ/mol, and OH_vap = 40.67 kJ/mol

A) 6.16
B) 9.88
C) 3870
D) 7.21
E) 12.28

Question 56

NaCl crystallizes in a face- centered cubic cell. What is the total number of ions (Na⁺ ions and Cl^- ions) that lie within a unit cell of NaCl?

A) 6
B) 2
C) 4
D) 8
E) 5

Question 57

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) cannot be liquefied above its triple point
C) sublimes rather than melts under ordinary conditions
D) cannot go from solid to liquid by application of pressure at any temperature
E) melts rather than sublimes under ordinary conditions

Question 58

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

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

Question 59

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

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

Question 60

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

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

Question 61

The direct conversion of a solid to a gas is called .

Question 62

The substance with the largest heat of vaporization is _ .
I₂
Br₂ Cl₂ F₂ O₂

A) O₂
B) Cl₂
C) I₂
D) F₂
E) Br₂

Question 63

Of the following, should have the highest critical temperature.

A) CCl₄
B) CF₄
C) H₂
D) CBr₄
E) CH₄

Question 64

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

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

Question 65

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

A) Kr
B) HCl
C) CH₃OH
D) H₂S
E) NH₃

Question 66

The heat of fusion of water is 6.01 kJ/mol. The heat capacity of liquid water is 75.3 J/mol · K. The conversion of 50.0 g of ice at 0.00°C to liquid water at 22.0°C requires kJ of heat.

A) 17.2
B) 3.8 × 10²
C) 0.469
D) 21.3
E) Insufficient data are given.

Question 67

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

A)
B)
C)
D)
E)

Question 68

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 O H_vap of this substance.

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

Question 69

Which one of the following derivatives of ethane has the highest boiling point?

A) C₂F₆
B) C₂Cl₆
C) C₂Br₆
D) C₂H₆
E) C₂I₆

Question 70

Of the following substances, _ has the highest boiling point.

A) H₂O
B) Kr
C) CH₄
D) CO₂
E) NH₃

Question 71

How many atoms are contained in a face- centered cubic unit cell?

Question 72

Chromium crystallizes in a body- centered cubic unit cell. There are chromium atoms per unit cell.

Question 73

London Dispersion Forces tend to in strength with increasing molecular weight.

Question 74

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 75

On a phase diagram, the critical temperature is .

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

Question 76

On the phase diagram below, 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) BC
C) AC
D) CD
E) AD

Question 77

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

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

Question 78

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

A)

B)
C)

D)
E)

Question 79

The scattering of light waves upon passing through a narrow slit is called .

A) grating
B) diffusion
C) incidence
D) adhesion
E) diffraction

Question 80

In general, intramolecular forces determine the properties of a substance and intermolecular forces determine its properties.