Deck 12: Intermolecular Forces: Liquids and Solids

Question 1

Which probably has the lowest boiling point at 1.0 atm pressure?

A)PbH₄
B)SnH₄
C)SiH₄
D)GeH₄
E)CH₄

Answer 1

CH₄

Question 2

Van der Waals forces are a type of London force.

Answer 2

False

Question 3

CH₄ probably has a lower boiling point at 1 atm than SnH₄.

Answer 3

True

Question 4

Which probably has the highest boiling point at 1.00 atm pressure?

A)H₂NCH₂CH₂NH₂
B)CH₃CH₂CH₂NH₂
C)(CH₃)₂CHNH₂
D)CH₃CH₂NHCH₃
E)(CH₃)₃N

Question 5

Below are given the Lewis structures of five molecules.Which one displays the LEAST hydrogen bonding?

A)
B)
C)
D)
E)

Question 6

Surface tension of a liquid is the work or energy required to increase the surface area of a liquid.

Question 7

If one compares compound A,composed of nonpolar molecules,with compound B,composed of polar molecules,and both molecules have the same molecular formula,then it is true that:

A)both compounds have the same boiling point
B)A boils at a lower temperature than B
C)B will not boil
D)B boils at a lower temperature than A
E)we have to know the structural formula to determine the differences in boiling points of A and B

Question 8

A liquid will "wet" a surface if:

A)the liquid has a lesser density than the surface
B)the forces between the liquid molecules are weak
C)the liquid has a low vapor pressure
D)the forces between the molecules and the surface are greater than the forces between the molecules of the liquid
E)The liquid has low viscosity and the surface is smooth

Question 9

Which probably has the lowest boiling point at 1.0 atm pressure?

A)C₂H₆
B)C₄H₁₀
C)C₆H₁₄
D)C₃H₈
E)C₅H₁₂

Question 10

Surface tension is thought to be due to:

A)surface area trying to increase
B)air absorbed on the surface
C)solute concentrated on the surface
D)surface molecules having lower energy than bulk molecules
E)surface molecules having higher energy than molecules in the bulk

Question 11

The property of a liquid that measures its resistance to flow is called resistivity.

Question 12

The phenomenon of supercooling refers to the existence of a metastable liquid at a temperature below that of its sublimation point.

Question 13

The process in which a gas is transformed into a solid is called solidification.

Question 14

H₂NCH₂CH₂NH₂ probably has a higher boiling point at 1.00 atm pressure than CH₃CH₂CH₂NH_2.

Question 15

The heat of deposition equals the negative of the heat of sublimation.

Question 16

Consider a parallelepiped with all edges being equal in length.There is an atom at each corner and one at the center of each face.This is a face-centered cubic cell.

Question 17

Which of the following statements concerning molecules in the liquid state is true?

A)Cohesive forces are not important.
B)The molecules contract to fit the size of the container.
C)The molecules have no motion.
D)The molecules are in a patterned (oriented)arrangement.
E)The molecules are mobile and relatively close together.

Question 18

Below are given the Lewis structures of five molecules.Which one displays the MOST hydrogen bonding?

A)
B)
C)
D)
E)

Question 19

Which of the following compounds has the highest boiling point?

A)NH₃
B)H₂O
C)HF
D)CH₄
E)HBr

Question 20

Consider a parallelepiped with all edges being equal in length.There is an atom at each corner and one in the center.This is a simple cubic cell.

Question 21

The enthalpy of fusion is:

A)the quantity of heat required to melt one mole of a solid
B)the quantity of heat released when a solid melts
C)the quantity of heat when two elements are fused together to produce binary compound
D)the quantity of heat required to fuse two atomic nuclei
E)the quantity of heat released when an organic compound burns in an atmosphere of pure oxygen

Question 22

Under which of the following conditions will vaporization best occur?

A)high mass,large surface area,high kinetic energy
B)weak forces between molecules,high kinetic energy,large surface area
C)high molecular energy,small surface area
D)low kinetic energy,strong molecular forces,large surface area
E)small surface area,low kinetic energy,low molecular mass

Question 23

Choose the INCORRECT statement.

A)In a network covalent solid,covalent bonds extend throughout the crystalline solid.
B)Diamond has sp³ hybridization.
C)Graphite has sp hybridization.
D)Fullerenes are a recently discovered allotropic form of carbons.
E)Nanotubes are an allotropic form of carbon.

Question 24

Which of the following statements about viscosity are true:
I.Viscosity is liquid's resistance to flow.
II.Viscosity decreases with a decrease in temperature.
III.Viscosity is not related to the forces between molecules in a liquid.
IV.Viscous liquids have low rate flows.

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

Question 25

A liquid has a normal boiling point of 78 °C and its vapor pressure is 400 mmHg at 50 °C.To compute the molar heat of vaporization,one needs:

A)the mole weight
B)the vapor pressure at another temperature
C)the specific heat
D)molarity
E)all information has been provided

Question 26

What is the difference between "normal boiling point" and "boiling point" of a liquid?

A)"Normal boiling point" is a boiling point of a liquid at normal (standard)pressure and temperature,while "boiling point" is measured at any other conditions of pressure and temperature.
B)"Normal boiling point" is a boiling point of 1 mol of a liquid with a surface of 1 m², while "boiling point" is boiling temperature for any other amount of a substance.
C)"Normal boiling point" is a boiling point a liquid has at 1 atm of pressure;"boiling point" is a boiling temperature of a liquid at any other pressure.
D)"Normal boiling point" and "boiling point" are synonyms.
E)"Normal boiling point" refers to 1 g of substance;"boiling point" refers to any other amount of substance.

Question 27

A liquid is in equilibrium with its vapor.If some of the vapor is allowed to escape,what is the immediate result?

A)The condensation rate decreases.
B)The vaporization rate increases.
C)The condensation rate increases.
D)The vaporization rate decreases.
E)The rates of condensation and vaporization are not effected.

Question 28

According to the phase diagram given,which of the following is INCORRECT?

A)At the temperature and pressure of point 1,substance U exists as a three-phase equilibrium system.
B)At the temperature and pressure of point 2,substance U exists as a one-phase gaseous system.
C)At the temperature and pressure of point 3,substance U exists as a two-phase system.
D)If the U(s)⇔ U(l)system is maintained at the temperature of point 4 while pressure is decreased steadily to about 300 Torr,more U will freeze.
E)There are no conditions of temperature and pressure under which solid U will vaporize without melting first.

Question 29

A passage of substance directly from the vapor to the solid state is known as:

A)deposition
B)decomposition
C)sublimation
D)solidification
E)fusion

Question 30

According to the phase diagram given,which of the following statements is INCORRECT?

A)At the temperature and pressure of point 2,substance Z exists as a three-phase equilibrium system.
B)At the temperature and pressure of point 3,substance Z exists as a one-phase gaseous system.
C)If the Z(s)= Z(l)= Z(g)system is maintained at the temperature of point 2 while pressure is decreased,more Z will vaporize.
D)If liquid Z is maintained at the pressure of point 4 while the temperature is decreased to 30 °C,the liquid will vaporize.
E)The existence of liquid Z at -50 °C and 2 atm represents the metastable condition of "supercooling."

Question 31

When a liquid is in dynamic equilibrium with its vapor at a given temperature,the following conditions could exist:
I.There is no transfer of molecules between liquid and vapor.
II.The vapor pressure has a unique value.
III.The opposing processes, (liquid to vapor)and (vapor to liquid),proceed at equal rates.
IV.The concentration of vapor is dependent on time.
Which of the above choices are applicable?

A)I
B)II and III
C)I,II,and III
D)II and IV
E)II,III and IV

Question 32

There are no types of crystalline solids that are held together by:

A)dipole-dipole interactions
B)ionic attractions
C)hydrogen bonds
D)covalent bonds
E)pi bonds only

Question 33

When a liquid is in equilibrium with its vapor in a closed container:

A)the rate at which molecules from the liquid phase enter the gas phase exactly equals the rate at which molecules from the gas phase pass into the liquid phase
B)a change in temperature will not change the pressure in the container
C)the amount of gas in the container must exactly equal the amount of liquid
D)molecules cannot go from the liquid phase to the gas phase because the amount of liquid in the container is constant
E)the vapor will gradually change back to the liquid state,that is,no vapor will be left

Question 34

Which of the following ionic compounds should have the highest melting point?

A)NaI
B)MgO
C)NaCl
D)LiBr
E)CaS

Question 35

Which of the following describe the critical point of a liquid?
I.the temperature and pressure at which a liquid's meniscus disappears
II.the point where the vapor pressure curve intersects the fusion temperature curve
III.the highest temperature and pressure at which a liquid can exist
IV.the highest temperature at which it is possible to obtain a liquid from its vapor by increasing pressure

A)I,II,III
B)I,III,IV
C)II,III
D)II,III,IV
E)I,IV

Question 36

Which of the following keeps the rate of vaporization unchanged?

A)closing container lid
B)increasing forces between molecules
C)increasing mass of molecule
D)decreasing temperature
E)decreasing surface area

Question 37

The phenomenon in which a steel needle can,with proper care,be made to float on the surface of some water illustrates a property of liquids known as:

A)compressibility
B)polarizability
C)surface tension
D)triple point
E)viscosity

Question 38

The phenomenon of supercooling refers to the existence of a metastable:

A)liquid at a temperature below that of its critical point
B)liquid at a temperature below that of its sublimation point
C)liquid at a temperature below that of its freezing point
D)gas at a temperature below that of its critical point
E)two-phase liquid/solid mixture at the freezing point

Question 39

Vaporization occurs more readily with:

A)increased temperature,increased surface area,decreased volume
B)increased temperature,increased surface area,increased intramolecular forces
C)increased temperature,decreased surface area,decreased intermolecular forces
D)increased temperature,increased surface area,decreased intermolecular forces
E)decreased temperature,decreased surface area,decreased intermolecular forces

Question 40

According to the phase diagram given,which of the following statements is INCORRECT?

A)At the temperature and pressure of point 1,W exists as a three-phase equilibrium system.
B)At the temperature of point 2,a pressure of 500 Torr will cause W to liquefy.
C)If the system is maintained at the temperature of point 3 while pressure is decreased,more W will vaporize.
D)If W is maintained at the pressure of point 4 while the temperature is increased to 80 °C,the liquid will vaporize.
E)The existence of liquid W at -40 °C and 500 Torr represents the metastable condition of "supercooling."

Question 41

The enthalpy of vaporization at 298 K for diethylether (C₄H₁₀O)is 26.0 kJ/mol.How much heat would be required to vaporize 1.00 L of the ether at 298 K if its density is 0.714 g/L?

A)440 J
B)250 J
C)186 J
D)130 J
E)74.1 J

Question 42

The enthalpy of condensation is equal to,but opposite in sign from,the enthalpy of ________.

A)crystallization
B)formation
C)fusion
D)sublimation
E)vaporization

Question 43

A crystal and its melt readily conduct electricity.The crystal also has a luster and is easily deformed.Thus,it is:

A)a covalent network crystal
B)an ionic crystal
C)a metallic crystal
D)a molecular crystal
E)a covalent crystal

Question 44

A compound of iron and sulfur crystallizes in a lattice pattern described as cubic closest packed sulfide ions,with iron ions in all octahedral sites.What is its empirical formula?

A)FeS
B)FeS₂
C)Fe₃S₄
D)Fe₂S
E)Fe₂S₃

Question 45

Flask A has a volume of 0.50 L and contains 50 g of a volatile liquid.Flask B has a volume of 1.0 L and contains 25 g of the same liquid.Both flasks are stoppered and both are at 30 °C.The ratio of the vapor pressure of the liquid in Flask A to that in Flask B is:

A)4:1
B)2:1
C)1:1
D)1:2
E)1:4

Question 46

The property of a liquid that measures its resistance to flow is called ________.

A)capillarity
B)polarizability
C)resistivity
D)viscosity
E)wettability

Question 47

An atom at the corner of cubic unit cell is shared among:

A)six adjoining unit cells
B)four adjoining unit cells
C)eight adjoining unit cells
D)ten adjoining unit cells
E)twelve adjoining unit cells

Question 48

Arrange the following compounds in order of increasing boiling point:
Pentane (CH₃CH₂CH₂CH₂CH₃),methyl butane (CH₃CH(CH₃)CH₂CH₃),neopentane (CH₃C(CH₃)₃).

A)pentane,methyl butane,neopentane
B)neopentane,methyl butane,pentane
C)neopentane,pentane,methyl butane
D)pentane,neopentane,methyl butane
E)methyl butane,pentane,neopentane

Question 49

Which of the substances below would produce the hardest crystals?

A)SiC
B)Xe
C)Cu
D)KNO₃
E)H₂O

Question 50

Coordination number is:

A)the number of atoms per unit cell
B)the number of atoms in the corners of the unit cell
C)the number of atoms in contact with a given atom
D)the number of atoms in the holes of closest packed structures
E)the number of layers in close packed structures

Question 51

Arrange the following compounds in order of increasing boiling point:
HCl,HBr,HI.

A)HCl,HBr,HI
B)HBr,HI,HCl
C)HI,HBr,HCl
D)HCl,HI,HBr
E)HI,HCl,HBr

Question 52

Arrange in order by decreasing boiling point:
Cl₂,I₂,HI

A)I₂,Cl₂,HI
B)Cl₂,I₂,HI
C)Cl₂,HI,I₂
D)HI,Cl₂,I₂
E)HI,I₂,Cl₂

Question 53

What is the maximum number of glycerol molecules [HOCH₂CH(OH)CH₂OH] that could form hydrogen bonds to a single molecule of the compound?

A)1
B)3
C)5
D)9
E)14

Question 54

The temperature at which the vapor pressure of a liquid equals the external pressure is called the ________.

A)boiling point
B)critical point
C)melting point
D)sublimation point
E)thermal point

Question 55

Three types of holes of the cubic closest packed structure are:

A)trigonal,tetrahedral and octahedral
B)tetrahedral,pyramidal and octahedral
C)tetrahedral,bipyramidal and octahedral
D)cubic,tetrahedral,and octahedral
E)tetragonal,tetrahedral and octahedral

Question 56

Which combination of "type of solid" and specific example is INCORRECT?

A)ionic/"table salt"
B)metallic/copper wire
C)molecular/"dry ice"
D)network covalent/iodine
E)network covalent/silicon carbide

Question 57

Which of the following compounds is the most viscous?
CH₃CH₂OH,CH₃CH₂CH₂CH₃,HOCH₂CH₂OH,CH₃OCH₂CH₃

A)CH₃CH₂OH
B)CH₃CH₂CH₂CH₃
C)CH₃OCH₂CH₃
D)HOCH₂CH₂OH

Question 58

Find a FALSE statement about X-rays.

A)diffracted by crystals
B)radiation of wavelength approximating 1 angstrom
C)visible to the naked eye
D)used to determine the structure of molecules
E)produced using high-energy electrons

Question 59

The property that causes water to have a concave meniscus but mercury to have a convex meniscus is ________.

A)heat of vaporization
B)sublimation
C)surface tension
D)vapor pressure
E)critical point

Question 60

Arrange in order by decreasing boiling point:
CH₃CH₂OH,HOCH₂CH₂OH,C₄H₁₀

A)HOCH₂CH₂OH,CH₃CH₂OH,C₄H₁₀
B)C₄H₁₀,HOCH₂CH₂OH,CH₃CH₂OH
C)HOCH₂CH₂OH,C₄H₁₀,CH₃CH₂OH
D)C₄H₁₀,CH₃CH₂OH,HOCH₂CH₂OH
E)CH₃CH₂OH,C₄H₁₀,HOCH₂CH₂OH

Question 61

Arrange the following compounds in order of increasing boiling point:
I.1-propanol,CH₃CH₂CH₂OH;
II.1,2-propanediol,CH₃CH(OH)CH₂OH;
III.1,2,3-propanetriol, (glycerol),HOCH₂CH(OH)CH₂OH.

A)II,III,I
B)I,II,III
C)III,I,II
D)III,II,I
E)I,III,II

Question 62

A substance has a heat of fusion of 61.5 kJ/mol and a heat of deposition of -167.4 kJ/mol.What is the heat of sublimation in kJ/mol?

A)-61.5 kJ/mol
B)61.5 - 167.4 kJ/mol
C)61.5 + 167.4 kJ/mol
D)167.4 - 61.5 kJ/mol
E)167.4 kJ/mol

Question 63

If a substance has a heat of condensation of -1.46 kJ/g and a heat of sublimation of 4.60 kJ/g,what is its heat of solidification in kJ/g?

A)4.60 - 1.46 kJ/g
B)-(4.60 + 1.46)kJ/g
C)1.46 - 4.60 kJ/g
D)4.60 + 1.46 kJ/g
E)0 kJ/g

Question 64

If 34 g of a solid with a molar mass = 174 g/mol requires 21.3 kJ to melt it,what is the molar heat of fusion in kJ/mol?

A)(21.3)(174)(34)kJ/mol
B)(21.3/174)(34)kJ/mol
C)(21.3/174)/34 kJ/mol
D)(21.3)(174/34)kJ/mol
E)(34/21.3)(174)kJ/mol

Question 65

Given the data below,determine the normal boiling point of COCl₂.
P₁ = 100 mmHg,t₁ = -35.6 °C,Δ_vapH = 27.4 kJ/mol

A)278 °C
B)-65.1 °C
C)-36.4 °C
D)5.0 °C
E)-5.0 °C

Question 66

How much heat would be released by the condensation of 5.40 g of steam at 100 °C and the subsequent cooling of the water to 25 °C?
[Δ_vapH = 40.7 kJ/mol at 100 °C;C_p for H₂O(l)is 4.18 J g^-1 °C^-1]

A)12.2 kJ
B)12.8 kJ
C)13.9 kJ
D)18.3 kJ
E)23.7 kJ

Question 67

A liquid has a molar heat of vaporization of 22.7 kJ/mol.Its normal boiling point is 459 K.What is the vapor pressure,in mmHg,at 70 °C?

A)102 mmHg
B)7.48 mmHg
C)56.8 mmHg
D)742 mmHg
E)580 mmHg

Question 68

When the vapor pressure of a liquid equals atmospheric pressure,the temperature of the liquid equals ________.

A)100 °C
B)the boiling point
C)the normal boiling point
D)the vaporization point
E)the sublimation point

Question 69

The maximum temperature at which a gas can be liquefied is just below the ________.

A)boiling temperature
B)critical temperature
C)melting temperature
D)normal temperature
E)superheating temperature

Question 70

The relationship between the vapor pressure of a liquid and temperature can be expressed by the Clausius-Clapeyron equation:
Ln[P₂/P₁] = [Δ_vapH/R] × [1/T₁ - 1/T₂]
Ethanol (C₂H₅OH)has a normal boiling point of 78.3 °C and,with Δ_vapH = 39.3 kJ/mol.What is the vapor pressure of ethanol at 50.0 °C?

A)118 Torr
B)234 Torr
C)354 Torr
D)485 Torr
E)670 Torr

Question 71

The normal boiling point of acetone is 56.2 °C and the molar heat of vaporization is 32.0 kJ/mol.At what temperature will acetone boil under a pressure of 50.0 mmHg?

A)156 °C
B)6.0 °C
C)-6.0 °C
D)40.7 °C
E)73.6 °C

Question 72

A 0.90 g sample of liquid water was introduced into an evacuated 2.00 L flask,which was then sealed and heated to 37 °C.What percentage,by mass,of the water remained as liquid? [Vapor pressure of water at 37 °C = 48.2 Torr.]

A)10%
B)18%
C)82%
D)90%
E)0%

Question 73

The factor that has the largest effect on the vapor pressure of a molecular substance is ________.

A)liquid surface area
B)molecular dipole moment
C)presence of H-bonding
D)liquid mole weight
E)volume available for vapor

Question 74

The heat of deposition equals the negative of the heat of ________.

A)fusion
B)condensation
C)sublimation
D)solidification
E)reposition

Question 75

Liquid and vapor phases of a substance become indistinguishable at the ________.

A)triple point
B)normal point
C)permanent point
D)critical point
E)absolute point

Question 76

Arrange the following compounds in order of increasing viscosity:
I.1-propanol,CH₃CH₂CH₂OH;
II.1,2-propanediol,CH₃CH(OH)CH₂OH;
III.1,2,3-propanetriol, (glycerol),HOCH₂CH(OH)CH₂OH.

A)I,II,III
B)II,III,I
C)III,I,II
D)III,II,I
E)I,III,II

Question 77

Given the data below,determine the normal boiling point of liquid Rb.
P₁ = 400 mmHg,t₁ = 620 °C,Δ_vapH = 78.5 kJ/mol

A)374 °C
B)920 °C
C)647 °C
D)951 °C
E)678 °C

Question 78

Given the data below,determine the molar enthalpy of vaporization of liquid Rb.
Rb,P₁ = 1.00 mmHg,t₁ = 297 °C,P₂ = 400 mmHg,t₂ = 620 °C

A)5.49 kJ/mol
B)28.4 kJ/mol
C)78.5 kJ/mol
D)12.8 kJ/mol
E)4.62 kJ/mol

Question 79

Given the data below,determine the molar enthalpy of vaporization of COCl₂.
COCl₂,P₁ = 40 mmHg,t₁ = -50.3 °C,P₂ = 100 mmHg,t₂ = -35.6 °C

A)0.518 kJ/mol
B)27.4 kJ/mol
C)4.32 kJ/mol
D)0.928 kJ/mol
E)0.112 kJ/mol

Question 80

What would be the appropriate equilibrium temperature of a system obtained by adding 25.0 g of ice at 0 °C to 250.0 mL of "hot" (80 °C)coffee,assuming that the heat capacity and density of the coffee are the same as for pure water (4.18 J g^-1 °C^-1 and 0.997 g mL^-1),and also assuming negligible heat transfer with the surroundings? [For water,Δ_fusH = 6.02 kJ/mol.]

A)33 °C
B)40 °C
C)65 °C
D)73 °C
E)79 °C