Deck 11: Intermolecular Forces and Liquids and Solids

Question 1

The intermolecular forces present in CO include which of the following
I. dipole-dipole
II. ion-dipole
III. dispersion
IV. hydrogen bonding

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

Answer 1

I and III

Question 2

Arrange the following substances in order of increasing boiling point: CH₃CH₂OH, HOCH₂CH₂OH, CH₃CH₂Cl, and ClCH₂CH₂OH

A) CH₃CH₂OH < HOCH₂CH₂OH < CH₃CH₂Cl < ClCH₂CH₂OH
B) CH₃CH₂Cl < CH₃CH₂OH < ClCH₂CH₂OH < HOCH₂CH₂OH
C) CH₃CH₂OH < CH₃CH₂Cl < HOCH₂CH₂OH < ClCH₂CH₂OH
D) CH₃CH₂Cl < ClCH₂CH₂OH < CH₃CH₂OH < HOCH₂CH₂OH
E) CH₃CH₂OH < ClCH₂CH₂OH < CH₃CH₂Cl < HOCH₂CH₂OH

Answer 2

CH₃CH₂Cl < CH₃CH₂OH < ClCH₂CH₂OH < HOCH₂CH₂OH

Question 3

Each of the following substances is a liquid at -50 ^$\circ$ C. Place these liquids in order of increasing vapor pressure: dimethyl ether (CH₃OCH₃), propane (C₃H₈), and ethanol (CH₃CH₂OH)_.

A) ethanol < propane < dimethyl ether
B) ethanol < dimethyl ether < propane
C) propane < dimethyl ether < ethanol
D) dimethyl ether < ethanol < propane
E) propane < ethanol < dimethyl ether

Answer 3

ethanol < dimethyl ether < propane

Question 4

Which of the following would be expected to have the highest vapor pressure at room temperature

A) ethanol, bp = 78 ^$\circ$ C
B) methanol, bp = 65 ^$\circ$ C
C) water, bp = 100 ^$\circ$ C
D) acetone, bp = 56 ^$\circ$ C

Question 5

Which one of the following substances is expected to have the highest boiling point

A) HBr
B) HCl
C) HF
D) HI

Question 6

Which of the following liquids would have the lowest viscosity at 25 ^$\circ$ C

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

Question 7

Which of the following characteristics indicates the presence of weak intermolecular forces in a liquid

A) a low heat of vaporization
B) a high critical temperature
C) a low vapor pressure
D) a high boiling point
E) None of the above.

Question 8

The intermolecular forces present in HSCH₂CH₂SH include which of the following
I. dipole-dipole
II. ion-dipole
III. dispersion
IV. hydrogen bonding

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

Question 9

The intermolecular forces present in C₆H₆ include which of the following
I. dipole-dipole
II. ion-dipole
III. dispersion
IV. hydrogen bonding

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

Question 10

For which of the following species are the dispersion forces strongest

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

Question 11

Which two properties are more typical of molecular compounds than of ionic compounds
1. They are gases or liquids at room temperature.
2. They have high melting points.
3. Solids do not conduct electricity, but liquids do.
4. Atoms share electrons.

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

Question 12

Which one of the following substances is expected to have the lowest melting point

A) BrI
B) CsI
C) LiI
D) NaI
E) RbI

Question 13

Arrange the following substances in order of increasing boiling point: CH₃OH, He, CH₃Cl, and N₂

A) CH₃OH < He < CH₃Cl < N₂
B) He < N₂ < CH₃OH < CH₃Cl
C) N₂ < He < CH₃OH < CH₃Cl
D) He < N₂ < CH₃Cl < CH₃OH
E) CH₃Cl < He < N₂ < CH₃OH

Question 14

Which one of the following substances is expected to have the highest boiling point

A) Br₂
B) Cl₂
C) F₂
D) I₂

Question 15

The intermolecular forces present in CH₃NH₂ include which of the following
I. dipole-dipole
II. ion-dipole
III. dispersion
IV. hydrogen bonding

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

Question 16

Which one of the following substances should exhibit hydrogen bonding in the liquid state

A) PH₃
B) H₂
C) H₂S
D) CH₄
E) NH₃

Question 17

Which one of the following substances is expected to have the highest melting point

A) CH₄
B) CCl₄
C) CO
D) CO₂
E) C(diamond)

Question 18

Which one of the following substances will have both dispersion forces and dipole-dipole forces

A) HCl
B) BCl₃
C) Br₂
D) H₂
E) CO₂

Question 19

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) None of the above.

Question 20

Which of the following liquids would have the highest viscosity at 25 ^$\circ$ C

A) CH₃OCH₃
B) CH₂Cl₂
C) C₂H₅OH
D) CH₃Br
E) HOCH₂CH₂OH

Question 21

Which one of the following substances should exhibit hydrogen bonding in the liquid state

A) PH₃
B) He
C) H₂S
D) CH₄
E) CH₃OH

Question 22

Arrange the following in order of increasing melting point: NaCl, H₂O, CH₄, C₆H₄(OH)₂.

A) NaCl < H₂O < CH₄ < C₆H₄(OH)₂
B) CH₄ < H₂O < NaCl < C₆H₄(OH)₂
C) CH₄ < H₂O < C₆H₄(OH)₂ < NaCl
D) CH₄ < C₆H₄(OH)₂ < H₂O < NaCl
E) CH₄ < NaCl < C₆H₄(OH)₂ < H₂O

Question 23

Which of the following properties is not influenced by hydrogen bonding

A) melting point
B) boiling point
C) vapor pressure
D) viscosity
E) flammability

Question 24

Which property of water allows a razor blade to float on it without sinking

A) viscosity
B) surface tension
C) density
D) specific heat
E) triple point

Question 25

Which one of the following substances should exhibit hydrogen bonding in the liquid state

A) SiH₄
B) H₂
C) H₂S
D) CH₄
E) CH₃NH₂

Question 26

Butter melts over a range of temperatures, rather than with a sharp melting point. Butter is classified as a/an

A) metallic crystal.
B) covalent solid.
C) molecular crystal.
D) amorphous solid.
E) ionic crystal.

Question 27

The boiling points of propanol (CH₃CH₂CH₂OH) and pentanol (CH₃CH₂CH₂CH₂CH₂OH) are 97 ^$\circ$ C and 137 ^$\circ$ C, respectively. The boiling point of butanol (CH₃CH₂CH₂CH₂OH) is predicted to be:

A) < 97 ^$\circ$ C
B) > 137 ^$\circ$ C
C) > 97 ^$\circ$ C and < 137 ^$\circ$ C
D) 97 ^$\circ$ C
E) 137 ^$\circ$ C

Question 28

The boiling points of chloromethane (CH₃Cl) and dichlormethane (CH₂Cl₂) are - 24 ^$\circ$ C and 40. ^$\circ$ C respectively. The boiling point of trichloromethane (CHCl₃) is predicted to be:

A) < - 24 ^$\circ$ C
B) > 40. ^$\circ$ C
C) > - 24 ^$\circ$ C and < 40. ^$\circ$ C
D) - 24 ^$\circ$ C
E) 40. ^$\circ$ C

Question 29

Which of the following is not true with regard to water

A) Water has a high heat capacity.
B) Water has an unusually high boiling point.
C) Water can form hydrogen bonds.
D) Ice is more dense than liquid water.
E) Water is a polar molecule.

Question 30

W(s) is classified as a/an

A) metallic crystal.
B) covalent solid.
C) molecular crystal.
D) amorphous solid.
E) ionic crystal.

Question 31

Each of the following substances is a gas at 25 ^$\circ$ C and 1 atmosphere pressure. Which one will liquefy most easily when compressed at a constant temperature

A) F₂
B) H₂
C) HF
D) SiH₄
E) Ar

Question 32

Which one of the following substances crystallizes as a molecular solid

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

Question 33

HOCH₂CH₂OH(s) is classified as a/an

A) metallic crystal.
B) covalent solid.
C) molecular crystal.
D) amorphous solid.
E) ionic crystal.

Question 34

An example of a covalent network solid is

A) diamond.
B) potassium.
C) iodine.
D) sodium chloride.
E) none of these.

Question 35

Which of following can form hydrogen bonds with water molecules
(1) Na⁺ (2) CH₃COOH (3) C₂H₆ (4) CH₃NH₂

A) (1) and (2)
B) (1) and (3)
C) (2) and (3)
D) (2) and (4)
E) (3) and (4)

Question 36

The structural form of the element Ge closely resembles the structure of

A) C (diamond).
B) N (diatomic).
C) As (tetrahedral).
D) S (S₈ ring).
E) Kr (monatomic).

Question 37

Which of the following would be expected to have the lowest vapor pressure at room temperature

A) ethanol, bp = 78 ^$\circ$ C
B) methanol, bp = 65 ^$\circ$ C
C) water, bp = 100 ^$\circ$ C
D) acetone, bp = 56 ^$\circ$ C

Question 38

Which one of the following is an example of a covalent network solid

A) SiO₂
B) K
C) I₂
D) CaCl₂
E) None of these.

Question 39

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 < CH₃Cl < CH₃OH < CH₄
D) CH₄ < CH₃OH < CH₃Cl < RbCl
E) CH₄ < CH₃Cl < CH₃OH < RbCl

Question 40

Given the following liquids and their boiling points, which has the highest vapor pressure at its normal boiling point

A) ethanol, bp = 78 ^$\circ$ C
B) methanol, bp = 65 ^$\circ$ C
C) water, bp = 100 ^$\circ$ C
D) benzene, bp = 80 ^$\circ$ C
E) The vapor pressure of each of the liquids at its normal boiling point would be the same.

Question 41

Glass is classified as a/an

A) metallic crystal.
B) covalent solid.
C) molecular crystal.
D) amorphous solid.
E) ionic crystal.

Question 42

Potassium bromide, KBr, crystallizes like NaCl in a face-centered lattice. The ionic radii of K⁺ and Br^- ions are 133 pm and 195 pm, respectively. Assuming that all Br^- ions are positioned in the face and corners of the unit cell, while the K⁺ ions are positioned along the edge alternating between anions, calculate the length of a unit cell edge.

A) 230 pm
B) 328 pm
C) 523 pm
D) 656 pm
E) 780 pm

Question 43

The number of nearest neighbors (atoms that make contact) around each atom in a face-centered cubic lattice of a metal is

A) 2.
B) 4.
C) 6.
D) 8.
E) 12.

Question 44

SrF₂ crystallizes such that the Sr²⁺ ions are in a face-centered cubic arrangement and the F^- ions are in the holes of the lattice (fluorite structure). How many F^- ions are present in one unit cell of this crystal

A) 1
B) 2
C) 4
D) 6
E) 8

Question 45

Which one of the following substances crystallizes as a covalent crystal

A) CaO
B) SiO₂
C) CO₂
D) Pb
E) KMnO₄

Question 46

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) 1.023 g/cm³
B) 2.032 g/cm³
C) 2.046 g/cm³
D) 3.081 g/cm³
E) 4.091 g/cm³

Question 47

The most space efficient arrangement of spheres is found in which type(s) of atom arrangement
I. hexagonal close-packed
II. cubic close-packed
III. simple cubic
IV. body-centered cubic

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

Question 48

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) 5.96 * 10^-30 g/cm³
B) 2.98 * 10^-6 g/cm³
C) 2.98 g/cm³
D) 5.96 g/cm³
E) 11.9 g/cm³

Question 49

Potassium crystallizes in a body-centered cubic lattice. How many atoms are there per unit cell

A) 1
B) 2
C) 4
D) 6
E) 8

Question 50

Palladium crystallizes in a face-centered cubic unit cell. Its density is 12.0 g/cm³ at 27 ^$\circ$ C. Calculate the atomic radius of Pd.

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

Question 51

A face-centered cubic unit cell is the repeating unit in which type of crystal packing

A) hexagonal close-packed
B) cubic close-packed
C) body centered
D) simple
E) all of the above

Question 52

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) 0.232 ^$\circ$
B) 2.63 ^$\circ$
C) 13.3 ^$\circ$
D) 27.4 ^$\circ$
E) 66.8 ^$\circ$

Question 53

MgO has the same crystal structure as NaCl, face-centered cubic. How many oxide ions surround each Mg²⁺ ion as nearest neighbors

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

Question 54

BaCl₂ crystallizes such that the Ba²⁺ ions are in a face-centered cubic arrangement and the Cl^- ions are in the holes of the lattice (fluorite structure). How many Cl^- ions are present in one unit cell of this crystal

A) 1
B) 2
C) 4
D) 6
E) 8

Question 55

Which one of the following crystallizes in a metallic lattice

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

Question 56

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

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

Question 57

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

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

Question 58

The mineral manganosite, manganese(II) oxide, crystallizes in the rock salt structure (the face-centered structure adopted by NaCl) with a density of 5.365 g/cm³. Find the unit cell edge length of manganosite.

A) 280.0 pm
B) 352.8 pm
C) 368.2 pm
D) 417.9 pm
E) 444.5 pm

Question 59

The most space efficient arrangement of spheres is found in which type of unit cell

A) face-centered cubic
B) body-centered cubic
C) simple cubic
D) face-centered cubic and body-centered cubic
E) body-centered cubic and simple cubic

Question 60

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

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

Question 61

Which of the following substances is expected to have the highest molar heat of vaporization ( $\Delta$ H_vap)

A) Ar
B) C₆H₆
C) He
D) NH₃
E) H₂O

Question 62

Acetic acid has a heat of fusion of 10.8 kJ/mol and a heat of vaporization of 24.3 kJ/mol. What is the expected value for the heat of sublimation of acetic acid

A) 35.1 kJ/mol
B) -13.5 kJ/mol
C) +13.5 kJ/mol
D) -35.1 kJ/mol
E) Not enough information is given to answer the question.

Question 63

A liquid boils when its

A) vapor pressure is exactly 1 atmosphere.
B) vapor pressure is equal to, or greater than, the external pressure pushing on it.
C) temperature is equal to 273 K (standard temperature).
D) temperature is greater than room temperature.

Question 64

How much energy (heat) is required to convert 25.5 g of H₂O(l) at 35.0 ^$\circ$ C to H₂O(g) at 115.0 ^$\circ$ C

specific heat of ice: $\quad 2.09 \mathrm{~J} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C} \quad \Delta \mathrm{H}_{\mathrm{fus}}=6.02 \mathrm{~kJ} / \mathrm{mol}$
specific heat of water: $4.18 \mathrm{~J} / \mathrm{g}{ \cdot}^{\circ} \mathrm{C} \quad \Delta \mathrm{H}_{\mathrm{vap}}=40.7 \mathrm{~kJ} / \mathrm{mo}$ .
specific hast of steam: $1.84 \mathrm{~J} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}$

A) 207 J
B) 7,630 J
C) 8,530 J
D) 9,130 J
E) 65,200 J

Question 65

Use the graph of vapor pressure to determine the normal boiling point of O₂.

A) 84 K
B) 88 K
C) 90 K
D) 92 K
E) O₂ doesn't boil because it is always a gas.

Question 66

Which of the following constants is/are needed to calculate the amount of energy required to heat 12.0g of H₂O(l) at 30.0 ^$\circ$ C to H₂O(l) at 85.0 ^$\circ$ C
I. $\Delta$ H_fus (H₂O)
II. $\Delta$ H_vap (H₂O)
III. specific heat of H₂O(s)
IV. specific heat of H₂O(l)
V. specific heat of H₂O(g)

A) I and IV
B) II and IV
C) IV only
D) I, II, and IV
E) IV and V

Question 67

Calculate the amount of heat needed to melt 2.00 kg of iron at its melting point (1,809 K), given that $\Delta$ H_fus = 13.80 kJ/mol.

A) 27,600 J
B) 27.6 kJ
C) 494 kJ
D) 25,000 kJ
E) 27,600 kJ

Question 68

The specific heat of liquid ethanol, C₂H₅OH(l), is 2.46 J/g· ^$\circ$ C and the heat of vaporization is 39.3 kJ/mol. The boiling point of ethanol is 78.3 ^$\circ$ C. What amount of enthalpy is required to heat 50.0 g of liquid ethanol from 23.0 ^$\circ$ C to ethanol vapor at 78.3 ^$\circ$ C

A) 42.7 kJ
B) 49.5 kJ
C) 179 kJ
D) 1970kJ
E) 6840 kJ

Question 69

Which of the following phase changes is endothermic

A) Sublimation
B) Condensation
C) Freezing
D) Deposition

Question 70

A phase change from the gas phase directly to the solid phase is called:

A) Sublimation
B) Condensation
C) Freezing
D) Melting
E) Deposition

Question 71

Which of the following constants is/are needed to calculate the amount of energy required to heat 30.5g of H₂O(s) at -25.0 ^$\circ$ C to H₂O(l) at 55.0 ^$\circ$ C
I. $\Delta$ H_fus (H₂O)
II. $\Delta$ H_vap (H₂O)
III. specific heat of H₂O(s)
IV. specific heat of H₂O(l)
V. specific heat of H₂O(g)

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

Question 72

Calculate the amount of heat that must be absorbed by 10.0 g of ice at -20 ^$\circ$ C to convert it to liquid water at 60.0 ^$\circ$ C. Given: specific heat (ice) = 2.1 J/g· ^$\circ$ C; specific heat (water) = 4.18 J/g· ^$\circ$ C; $\Delta$ H_fus = 6.0 kJ/mol.

A) 63 kJ
B) 7.5 J
C) 420 J
D) 2,900 J
E) 6,300 J

Question 73

The vapor pressure of ethanol is 400 mmHg at 63.5 ^$\circ$ C. Its molar heat of vaporization is 39.3 kJ/mol. What is the vapor pressure of ethanol, in mmHg, at 34.9 ^$\circ$ C

A) 0.0099 mmHg
B) 4.61 mmHg
C) 100 mmHg
D) 200 mmHg
E) 1,510 mmHg

Question 74

The vapor pressure of a liquid in a closed container depends upon

A) the amount of liquid.
B) the surface area of the liquid.
C) the volume of the container.
D) the temperature.
E) none of the above.

Question 75

The heat capacity of liquid water is 4.18 J/g· ^$\circ$ C and the heat of vaporization is 40.7 kJ/mol. How many kilojoules of heat must be provided to convert 1.00 g of liquid water at 67 ^$\circ$ C into 1.00 g of steam at 100 ^$\circ$ C

A) 40.8 J
B) 2.2 kJ
C) 2,400 J
D) 22.7 kJ
E) 40.8 kJ

Question 76

Which of the following phase changes is exothermic

A) Sublimation
B) Condensation
C) Melting
D) Vaporization

Question 77

How much energy (heat) is required to convert 52.0 g of ice at -10.0 ^$\circ$ C to steam at 100 ^$\circ$ C

specific heat of ice: $\quad 2.09 \mathrm{~J} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C} \quad \Delta \mathrm{H}_{\mathrm{fus}}=6.02 \mathrm{~kJ} / \mathrm{mol}$
specific heat of water: $4.18 \mathrm{~J} / \mathrm{g}{ \cdot}^{\circ} \mathrm{C} \quad \Delta \mathrm{H}_{\mathrm{vap}}=40.7 \mathrm{~kJ} / \mathrm{mo}$ .
specific heat of steam: $1.84 \mathrm{~J} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}$

A) 40.2 kJ
B) 157.8 kJ
C) 1,086 kJ
D) 2,570 kJ
E) 22,957 kJ

Question 78

What mass of water would need to evaporate from your skin in order to dissipate 1.7 * 10⁵ J of heat from your body
H₂O(l) $\rarr$ H₂O(g) $\Delta$ H_vap = 40.7 kJ/mol

A) 58.4 g
B) 75.2 g
C) 418 g
D) 7.52 * 10⁴ g
E) 6.92 * 10⁶ g

Question 79

The triple point of iodine is at 0.12 atm and 115 ^$\circ$ C. Thus, liquid I₂

A) is more dense than I₂ (s).
B) cannot exist above 115 ^$\circ$ C.
C) is liquid at room temperature.
D) cannot have a vapor pressure less than 91 torr.

Question 80

Use the graph of vapor pressure to determine the normal boiling point of CHCl₃.

A) 19 ^$\circ$ C
B) 52 ^$\circ$ C
C) 60 ^$\circ$ C
D) 64 ^$\circ$ C
E) 70 ^$\circ$ C