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

Question 1

Which of the following is defined as the attractive forces between polar molecules?

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

Answer 1

II only

Question 2

Which substance will exhibit hydrogen bonding between molecules?

A) (CH₃)₃N
B) CH₃-O-CH₃
C) CH₃CH₂-OH
D) CH₃CH₂-F
E) HI

Answer 2

CH₃CH₂-OH

Question 3

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

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

Answer 3

dipole-dipole forces

Question 4

Which substance should exhibit hydrogen bonding in the liquid phase?

A) PH₃
B) He
C) H₂S
D) CH₄
E) CH₃OH

Question 5

Which one of the following pure substance has both dispersion forces and dipole-dipole forces?

A) HCl
B) BCl₃
C) Br₂
D) H₂
E) CO₂

Question 6

Which of the responses includes all of the following that can form hydrogen bonds with water molecules? I. Na⁺, II. CH₃COOH, III. C₂H₆, IV. CH₃NH₂

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

Question 7

In which of the following compounds will the molecules not form hydrogen bonds with each other?

A)
B)
C)
D)
E)

Question 8

The strongest intermolecular interactions between hydrogen fluoride (HF) molecules arise from

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

Question 9

Helium atoms do not combine to form He₂ molecules, yet He atoms do attract one another weakly through

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

Question 10

What types of intermolecular forces exist between hydrogen fluoride molecules?

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

Question 11

Which one of the following pure substances will exhibit hydrogen bonding?

A) CH₄
B) H₂C=CH₂
C) H₂O
D) CHCl₃
E) CHF₃

Question 12

Which are considered van der Waals forces?

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

Question 13

Which of the following atoms does not participate in hydrogen bonding?

A) S
B) O
C) F
D) N
E) H

Question 14

Which kinds of intermolecular forces exist between propane molecules?

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

Question 15

The strongest intermolecular interactions between hydrogen sulfide (H₂S) molecules arise from

A) dipole-dipole forces.
B) London dispersion forces.
C) hydrogen bonding.
D) ion-dipole interactions.
E) disulfide linkages.

Question 16

Ammonia's unusually high melting point is the result of

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

Question 17

The strongest intermolecular interactions between ethyl alcohol (CH₃CH₂OH) molecules arise from

A) dipole-dipole forces.
B) London dispersion forces.
C) hydrogen bonding.
D) ion-dipole interactions.
E) carbon-oxygen bonds.

Question 18

What is the name given to the attractive forces that hold particles together in the condensed phase?

A) ionic bonds
B) covalent bonds
C) intermolecular forces
D) electronegativity
E) electron attraction

Question 19

What is another name given to dispersion forces?

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

Question 20

The strongest intermolecular interactions between pentane (C₅H₁₂) molecules arise from

A) dipole-dipole forces.
B) London dispersion forces.
C) hydrogen bonding.
D) ion-dipole interactions.
E) carbon-carbon bonds.

Question 21

What is the attractive force between like molecules involved in capillary action?

A) Surface tension
B) Adhesion
C) Polarity
D) Viscosity
E) Cohesion

Question 22

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

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

Question 23

What is the intermolecular force that exists between a calcium ion and water?

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

Question 24

Which of the following pure substances would be expected to have the highest boiling point?

A) CH₄
B) Cl₂
C) Kr
D) CH₃Cl
E) N₂

Question 25

Which of the following pure substances would be expected to have the highest boiling point?

A) CF₄
B) CCl₄
C) CBr₄
D) CI₄
E) CH₄

Question 26

Choose the response that lists the member of each of the following pairs that has the higher boiling point. I. H₂O or KI, II. HF or HI, III. Cl₂ or Br₂

A) H₂O, HF, and Cl₂
B) KI, HF, and Br₂
C) KI, HI, and Br₂
D) H₂O, HI, and Cl₂
E) KI, HF, and Cl₂

Question 27

Which would be expected to have the highest surface tension at a given temperature?

A)
B)
C)
D)
E)

Question 28

What name is given to a quantitative measure of the elastic force in the surface of a liquid?

A) Surface tension
B) Adhesion
C) Polarity
D) Capillary action
E) Cohesion

Question 29

Arrange the following in order of increasing boiling point: RbCl, CH₃Cl, CH₃OH, CH₄.

A) CH₃OH < CH₃Cl < RbCl < CH₄
B) CH₃OH < CH₄ < CH₃Cl < RbCl
C) RbCl < CH₃ Cl < CH₃ OH < CH₄
D) CH₄ < CH₃OH < CH₃Cl < RbCl
E) CH₄ < CH₃Cl < CH₃OH < RbCl

Question 30

What is the name given for the attraction between unlike molecules involved in capillary action?

A) Adhesion
B) Ionization
C) Cohesion
D) Surface tension
E) Viscosity

Question 31

What name is given to the phenomenon where a thin film of water contracts and adheres to the wall of a glass cylinder?

A) Surface tension
B) Adhesion
C) Polarity
D) Capillary action
E) Cohesion

Question 32

For which of the following pure substances are the intermolecular interactions entirely due to dispersion forces?

A) C₂H₆
B) CH₃OCH₃
C) NO₂
D) H₂S
E) Ca(NO₃)₂

Question 33

Which would be expected to have the highest surface tension at room temperature?

A) CH₄
B) CF₄
C) CCl₄
D) CBr₄
E) CI₄

Question 34

What is the intermolecular force that exists between a magnesium ion and hydrogen sulfide?

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

Question 35

Which of the following pure substances has the strongest dispersion forces?

A) C₄H₁₀
B) C₅H₁₂
C) C₆H₁₄
D) C₇H₁₆
E) C₈H₁₈

Question 36

At a temperature of 27 K, neon condenses due to

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

Question 37

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

A) Surface tension
B) Adhesion point
C) Meniscus
D) Capillary point
E) Cohesion point

Question 38

Which one of the following involves ion-dipole interactions?

A) Na⁺ and Cl^-
B) H⁺ and F^-
C) Na⁺ and Mg²⁺
D) two water molecules
E) Na⁺ and H₂O

Question 39

Krypton has a higher melting point than argon because of its

A) hydrogen bonding.
B) stronger dispersion forces.
C) permanent dipole moment.
D) ionic bonds.
E) greater ionization energy.

Question 40

Octane is a component of fuel used in internal combustion engines. The dominant intermolecular forces in octane are

A) dipole-dipole forces.
B) London dispersion forces.
C) hydrogen bonding.
D) covalent bonds.
E) carbon-hydrogen bonds.

Question 41

A) 34.7 kJ/mol
B) 21.9 kJ/mol
C) 3.45 kJ/mol
D) 712 J/mol
E) 9.99 kJ/mol

Question 42

Octane is a liquid component of gasoline. Given the following vapor pressures of octane at various temperatures, estimate the boiling point of octane in Leadville, Colorado, where the atmospheric pressure is 496 mmHg. (R = 8.314 J/K • mol)

A) 125°C
B) 120°C
C) 115°C
D) 110°C
E) 105°C

Question 43

The vapor pressure of ethanol is 400. mmHg at 63.5°C. Its molar heat of vaporization is 39.3 kJ/mol. What is the vapor pressure of ethanol, in mmHg, at 34.9°C? (R = 8.314 J/K • mol)

A) 109 mmHg
B) 220 mmHg
C) 366 mmHg
D) 376 mmHg
E) 1470 mmHg

Question 44

At what temperature does ethanol boil on a day in the mountains when the barometric pressure is 547 mmHg? The heat of vaporization of ethanol is 39.3 kJ/mol and its normal boiling point is 78.3°C. (R = 8.314 J/K • mol)

A) 76.5°C
B) 69.9°C
C) 10.0°C
D) 77.9°C
E) 74.6°C

Question 45

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

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 point

Question 46

Select the pair of substances in which the one with the lower vapor pressure at a given temperature is listed first.

A)
B) PH₃, NH₃
C) CF₄, CBr₄
D) C₃H₈, C₄H₁₀
E) F₂, Cl₂

Question 47

The molar enthalpy of vaporization of boron tribromide is 30.5 kJ/mol, and its normal boiling point is 91°C. What is the vapor pressure of BBr₃ at 20.°C? (R = 8.314 J/K • mol)

A) 11.5 torr
B) 659 torr
C) 255 torr
D) 66.2 torr
E) 167 torr

Question 48

Select the pair of substances in which the one with the higher vapor pressure at a given temperature is listed first.

A) C₇H₁₆, C₅H₁₂
B) CCl₄, CBr₄
C) H₂O, H₂S
D) CH₃CH₂OH, CH₃-O-CH₃
E) Xe, Kr

Question 49

Which of the following factors can contribute to the viscosity for a liquid?

A) Temperature
B) Hydrogen bonding
C) Molecular entanglements
D) London forces
E) All of the answers are correct.

Question 50

Octane has a vapor pressure of 40. torr at 45.1°C and 400. torr at 104.0°C. What is its heat of vaporization? (R = 8.314 J/K • mol)

A) 39.1 kJ/mol
B) 46.0 kJ/mol
C) 590 kJ/mol
D) 710 kJ/mol
E) None of these choices is correct.

Question 51

If the adhesive forces between a liquid and the walls of a capillary tube are greater than the cohesive forces within the liquid,

A) the liquid level in a capillary tube will rise above the surrounding liquid and the surface in the capillary tube will have a convex meniscus.
B) the liquid level in a capillary tube will rise above the surrounding liquid and the surface in the capillary tube will have a concave meniscus.
C) the liquid level in a capillary tube will drop below the surrounding liquid and the surface in the capillary tube will have a convex meniscus.
D) the liquid level in a capillary tube will drop below the surrounding liquid and the surface in the capillary tube will have a concave meniscus.
E) the liquid level in a capillary tube will be flat.

Question 52

The number of atoms in a body-centered cubic unit cell is

A) 1.
B) 2.
C) 3.
D) 4.
E) 8.

Question 53

Which corresponds to the temperature-dependent partial pressure above the surface of a liquid?

A) Surface tension
B) Vapor pressure
C) Boiling point
D) Viscosity
E) Capillary action

Question 54

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?

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/mol

Question 55

If a molecule at the surface of a liquid has enough kinetic energy to escape the liquid phase and enter the gas phase, then which of the following terms is used to describe this phenomenon?

A) Boiling point
B) Condensation
C) Vaporization
D) Sublimation
E) Gasification

Question 56

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

A) Surface tension
B) Adhesion
C) Polarity
D) Viscosity
E) Cohesion

Question 57

The molar enthalpy of vaporization of hexane (C₆H₁₄) is 28.9 kJ/mol, and its normal boiling point is 68.73°C. What is the vapor pressure of hexane at 25°C? (R = 8.314 J/K • mol)

A) 171 torr
B) 4.44 torr
C) 117 torr
D) 3370 torr
E) 759 torr

Question 58

Which substance has the lowest vapor pressure at room temperature?

A) HF
B) HCl
C) HBr
D) HI
E) H₂

Question 59

Which substance has the highest vapor pressure at room temperature?

A) HF
B) HCl
C) HBr
D) HI
E) All of these substances have the same vapor pressure at room temperature.

Question 60

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

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 themselves

Question 61

A metal such as chromium in the body-centered cubic lattice has ________ atom(s) per unit cell.

A) 1
B) 2
C) 3
D) 4
E) 9

Question 62

Which one of the following crystallizes in a metallic lattice?

A) C
B) NaMnO₄
C) K
D) LiClO₄
E) K₂Cr₂O₇

Question 63

Vanadium crystallizes in a body-centered cubic lattice, and the length of the edge of a unit cell is 305 pm. What is the density of V?

A) 0.712 g/cm³
B) 2.98 g/cm³
C) 5.96 g/cm³
D) 8.77 g/cm³
E) 11.9 g/cm³

Question 64

One of the crystalline forms of zinc oxide is a structure where the oxygen atoms are at the lattice points in a face-centered cubic lattice. How many atoms are in each unit cell?

A) 2
B) 4
C) 6
D) 8
E) 10

Question 65

What is the energy in kJ/mol required to melt 1 mole of a solid?

A) molar heat of freezing
B) molar heat of fission
C) molar heat of vaporization
D) molar heat of fusion
E) molar heat of condensation

Question 66

The zincblende structure of ZnS has the relatively large sulfide ions arranged at the lattice points of a face-centered cubic structure. The edge length of this cubic unit cell is 540.9 pm. Determine the density of zincblende.

A) 0.244 g/cm³
B) 1.02 g/cm³
C) 2.05 g/cm³
D) 4.09 g/cm³
E) 8.18 g/cm³

Question 67

Iron crystallizes in the body-centered cubic lattice. What is the coordination number for Fe?

A) 4
B) 6
C) 8
D) 10
E) 12

Question 68

What mass of water would need to evaporate from your skin in order to dissipate 1.70 ×10⁵ J of heat from the surface of your body? H₂O(l) → H₂O(g) ΔH_vap = 40.7 kJ/mol

A) 2.26 g
B) 4.18 g
C) 75.2 g
D) 4.18 ×10³ g
E) 4.07 × 10⁴ g

Question 69

Which of the following lacks a regular three-dimensional arrangement of atoms?

A) crystalline solid
B) ionic crystal
C) solid
D) amorphous solid
E) molecular solid

Question 70

Which one of the following substances crystallizes as a molecular solid?

A) KI
B) SiO₂
C) Sn
D) CH₃OH
E) Al₂(SO₄)₃

Question 71

For the solid forms of the following elements, which one is most likely to be of the molecular type?

A) Cs
B) C
C) Pb
D) S
E) Cr

Question 72

Which one of the following substances does not exist in the indicated solid type?

A) graphite-covalent crystals
B) Na-metallic crystals
C) SiO₂-molecular crystals
D) NaCl-ionic crystals
E) diamond-covalent crystals

Question 73

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

A) ΔH_sub = ΔH_fus - ΔH_vapV_liq
B) ΔH_sub = ΔH_dep + ΔH_fus
C) ΔU_sub= ΔU_fus + ΔU_vap
D) ΔH_sub = ΔH_fus - ΔH_vap
E) ΔH_sub = ΔH_fus + ΔH_vap

Question 74

The number of atoms in a face-centered cubic unit cell is

A) 1.
B) 2.
C) 3.
D) 4.
E) 8.

Question 75

Lead crystallizes in the face-centered cubic lattice. What is the coordination number for Pb?

A) 4
B) 6
C) 8
D) 10
E) 12

Question 76

What quantity of heat is required to melt 2.00 kg of iron at its melting point (1809 K)? For iron, ΔH_fus = 13.80 kJ/mol.

A) 0.385 kJ
B) 6.90 kJ
C) 27.6 kJ
D) 494 kJ
E) 771 kJ

Question 77

Platinum has a face-centered cubic crystal structure and a density of 21.5 g/cm³. What is the radius of a platinum atom?

A) 69 pm
B) 98 pm
C) 139 pm
D) 196 pm
E) 277 pm

Question 78

If liquid bromine is cooled to form a solid, which type of solid does it form?

A) atomic
B) metallic
C) molecular
D) ionic
E) covalent

Question 79

Palladium crystallizes in a face-centered cubic unit cell. Its density is 12.0 g/cm³ at 27°C. What is the atomic radius of Pd?

A) 138 pm
B) 1.95 × 10^-8 nm
C) 1.95 × 10^-8 cm
D) 154 pm
E) 0.109 nm

Question 80

The atomic planes in a graphite crystal are separated by 335 pm. At what angle would you find the first-order (n = 1) diffraction of 0.154-nm X rays from a graphite crystal?

A) 27.4°
B) 66.8°
C) 0.232°
D) 13.3°
E) 38.0°