Question 1

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

Accepted Answer

HI and H₂S are both polar molecules, so they exhibit dipole-dipole interactions. Additionally, all molecules experience dispersion forces. There are no ions present, so ion-dipole forces do not occur, and neither molecule can form hydrogen bonds.

Question 2

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.

Accepted Answer

All molecules exhibit dispersion forces in addition to any other intermolecular forces they may have, including hydrogen bonding.

Question 3

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

Accepted Answer

The compound with the highest ΔH_vap value has the strongest intermolecular forces. In this case, water has the highest value, indicating that it has the strongest intermolecular forces.

Question 4

C₁₂H₂₆ molecules are held together by ________. A)ion-ion interactions B)hydrogen bonding C)ion-dipole interactions D)dipole-dipole interactions E)dispersion forces

Accepted Answer

C₁₂H₂₆ (dodecane) is a nonpolar molecule, and the primary intermolecular forces between nonpolar molecules are dispersion forces (also known as London dispersion forces).

Question 5

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

Accepted Answer

The shape of a liquid's meniscus is determined by the relative magnitudes of cohesive forces in the liquid and adhesive forces between the liquid and its container. This determines whether the liquid will be more attracted to the container or to itself, leading to a concave or convex meniscus, respectively. The other choices do not directly affect the shape of the meniscus.

Question 6

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

Accepted Answer

All of the above options are manifestations of large intermolecular forces in a substance. Low vapor pressure occurs because the strong forces between molecules make it difficult for them to break away and become a gas. High boiling points occur because the strong intermolecular forces require a large amount of energy to break and allow the substance to change phase. High heats of fusion and vaporization occur because the strong forces require a significant amount of energy to break during phase changes. High critical temperatures and pressures occur because the strong forces make it difficult for the substance to transition to a gas phase, requiring high temperatures and pressures for this to occur.

Question 7

What type(s)of intermolecular forces exist between PH₃ and CO₃²^-? 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

Accepted Answer

PH₃ is a polar molecule, and CO₃²⁻ is an ion, so ion-dipole forces can exist between them. Additionally, all molecules experience dispersion forces.

Question 8

-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

Accepted Answer

During phase changes, such as melting or boiling, heat energy is used to overcome intermolecular forces and increase the distance between molecules, rather than increasing temperature.

Question 9

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

Accepted Answer

Viscosity is influenced by temperature, molecular weight, and intermolecular forces. As temperature decreases, molecules move slower and have more interactions, increasing viscosity. Higher molecular weight means larger molecules, which typically interact more strongly and move more slowly relative to each other, increasing viscosity. Stronger intermolecular forces also lead to increased resistance to flow, hence higher viscosity.

Question 10

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.

Accepted Answer

Both Br2 and CCl4 are nonpolar molecules, so the only intermolecular forces present between them are dispersion forces (also known as London dispersion forces).

Question 11

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

Accepted Answer

The heat of sublimation is the energy required to change a substance from solid to gas phase directly. This process can be thought of as occurring in two steps: first, the solid melts to a liquid (heat of fusion), and then the liquid vaporizes to a gas (heat of vaporization). Adding the heat of fusion and the heat of vaporization gives an approximation of the heat of sublimation.

Question 12

________ 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

Accepted Answer

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

Question 13

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

Accepted Answer

Viscosity is the property of a fluid that describes its resistance to flow.

Question 14

The property responsible for the "beading up" of water is ________.
A)density
B)viscosity
C)vapor pressure
D)surface tension
E)hydrogen bonding

Accepted Answer

Surface tension is the property responsible for the "beading up" of water because it is a measure of the attractive forces between the molecules at the surface of a liquid. These forces cause the surface to contract and form droplets, making it difficult for other substances to penetrate the surface.

Question 15

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

Accepted Answer

NH3 and H2S both have dispersion forces and dipole-dipole forces due to their polar nature, but hydrogen bonding does not occur between NH3 and H2S.

Question 16

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.

Accepted Answer

The heat of sublimation is equal to the sum of the heat of vaporization (energy required to vaporize a substance) and the heat of sublimation (energy required to convert a substance from a solid to a gas), whereas the heat of freezing is the energy released when a substance changes from a liquid to a solid. Therefore, statement C is false as it incorrectly adds the heat of freezing instead of the heat of sublimation.

Question 17

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

Accepted Answer

NH3 and HF both have hydrogen atoms bonded to highly electronegative atoms (N and F, respectively), allowing for hydrogen bonding. They also have permanent dipoles, leading to dipole-dipole interactions, and all molecules exhibit dispersion forces.

Question 18

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

Accepted Answer

The height to which a liquid will rise up a narrow tube as a result of capillary action depends on the balance between cohesive forces within the liquid and adhesive forces between the liquid and the tube, as well as the gravitational force acting on the liquid. Therefore, the correct option is A, as it includes all the relevant factors. The viscosity of the liquid will influence the speed at which it rises, but not the height reached. Option B is incorrect as the height does not only depend on gravity. Option C is incorrect as it does not consider cohesive forces. Option E is incorrect as it only considers cohesive forces, not adhesive forces or gravity.

Question 19

Which compound has the strongest intermolecular forces? A)CBr₄ B)C₁₂H₂₆ C)CI₄ D)N₂ E)O₂

Accepted Answer

CI₄ has the strongest intermolecular forces due to its larger size and greater polarizability compared to the other compounds, leading to stronger London dispersion forces.

Question 20

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.

Accepted Answer

All molecules exhibit dispersion forces in addition to any other intermolecular forces they may have, such as hydrogen bonding.

Quiz 11: Liquids and Intermolecular Forces

What types of intermolecular forces exist between HI and H₂S?

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

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

C₁₂H₂₆ molecules are held together by ________.

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

Large intermolecular forces in a substance are manifested by ________.

What type(s) of intermolecular forces exist between PH₃ and CO₃²^-?

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

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.

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

Heat of sublimation can be approximated by adding together and .

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

Viscosity is ________.

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

What types of intermolecular forces exist between NH₃ and H₂S?

Which of the following statements is false?

What types of intermolecular forces exist between NH₃ and HF?

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

Which compound has the strongest intermolecular forces?

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

Quiz 11: Liquids and Intermolecular Forces

What types of intermolecular forces exist between HI and H2S?

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

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

C12H26 molecules are held together by ________.

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

Large intermolecular forces in a substance are manifested by ________.

What type(s) of intermolecular forces exist between PH3 and CO32-?

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

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.

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

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

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

Viscosity is ________.

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

What types of intermolecular forces exist between NH3 and H2S?

Which of the following statements is false?

What types of intermolecular forces exist between NH3 and HF?

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

Which compound has the strongest intermolecular forces?

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

What types of intermolecular forces exist between HI and H₂S?

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

C₁₂H₂₆ molecules are held together by ________.

What type(s) of intermolecular forces exist between PH₃ and CO₃²^-?

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

Heat of sublimation can be approximated by adding together and .

What types of intermolecular forces exist between NH₃ and H₂S?

What types of intermolecular forces exist between NH₃ and HF?