Free Practice Quiz Question List

12 Intermolecular Forces and States of Matter Online Quiz Questions

Use this free practice quiz with 20 questions to review 12 Intermolecular Forces and States of Matter, test your knowledge, and prepare for your next test or exam.

20 questions

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1 point

A sample of argon atoms can attract one another even though each atom is nonpolar. Which intermolecular force accounts for this attraction?

A
Dipole–dipole attractions, because each atom has a permanent dipole
B
London dispersion forces, caused by temporary shifts in electron distribution
C
Hydrogen bonding, because one atom attracts a neighboring lone pair
D
Ion–dipole attractions, because argon atoms carry partial ionic charges

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1 point

Ammonia molecules and methanol molecules are neighbors. Which description identifies a hydrogen bond specifically between these molecules?

A
It is not hydrogen bonding because the two molecules are different substances.
B
It is hydrogen bonding because carbon in methanol attracts a hydrogen on ammonia.
C
It is hydrogen bonding because hydrogen bonded to nitrogen is attracted to oxygen's lone pair.
D
It is hydrogen bonding because the oxygen–hydrogen bond in methanol attracts nitrogen's nucleus.

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1 point

In an aqueous sodium chloride solution, what kind of intermolecular attraction describes the interaction between a dissolved Na⁺ ion and a neighboring water molecule?

A
Ion–dipole attraction
B
Dipole–dipole attraction
C
Hydrogen bonding
D
London dispersion force only

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1 point

At room temperature, F₂ and Cl₂ are gases, Br₂ is a liquid, and I₂ is a solid. Which explanation best accounts for this trend?

A
Their dipole–dipole attractions increase down the group, changing all halogens from gases to solids.
B
Their hydrogen bonds become stronger down the group, producing the phase trend.
C
Their ion–dipole attractions increase as the atoms gain electrons, causing the phase trend.
D
Their dispersion forces tend to strengthen as electron number and electron-cloud distortability increase.

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1 point

Two comparable liquids are at the same temperature in closed containers. Liquid B has stronger attractions between its particles than liquid A. Which prediction about their equilibrium vapor pressures is best supported?

A
Liquid B has a higher vapor pressure because stronger attractions push more molecules into the gas.
B
Liquid B has a lower vapor pressure because stronger attractions make escape from the liquid less likely.
C
The liquids must have equal vapor pressures because they are at the same temperature.
D
Liquid B has a lower vapor pressure only if its external pressure is also lower.

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1 point

Two comparable liquids differ mainly in the strength of attraction between neighboring particles. Liquid B has stronger attractions. Which pair of property trends is most consistent with the material?

A
Liquid B is expected to have lower viscosity and lower surface tension.
B
Liquid B is expected to have higher viscosity but lower surface tension.
C
Liquid B is often expected to have greater viscosity and greater surface tension.
D
Liquid B must have the same viscosity and surface tension because both are liquids.

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1 point

A liquid is heated under a reduced external pressure rather than its usual external pressure. Assuming the liquid remains the same, how does the boiling temperature change, and why?

A
Its boiling temperature decreases because the liquid needs a lower vapor pressure to match the reduced external pressure.
B
Its boiling temperature increases because fewer gas particles press on the liquid.
C
Its boiling temperature stays fixed because only intermolecular attractions determine boiling.
D
It can no longer boil because vapor pressure cannot equal a reduced external pressure.

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1 point

An open container of liquid releases some vapor from its surface while the liquid is below its boiling point. Which interpretation is correct?

A
The liquid is boiling because any formation of vapor requires its vapor pressure to equal the surrounding pressure.
B
The liquid is not changing state because vaporization can occur only at the boiling temperature.
C
The liquid is boiling if any molecules escape, even when vapor forms only at the surface.
D
The liquid can be evaporating at its surface without boiling throughout the liquid.

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1 point

A substance's particles remain close together, yet they can move past neighboring particles rather than staying near fixed positions. Which phase does this particle model describe?

A
A gas, because its particles are close together but move past one another.
B
A liquid, because its particles remain close together but can move past one another.
C
A solid, because its particles move freely while remaining close together.
D
A gas, because its particles vibrate around fixed positions.

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1 point

At a fixed pressure, a sample reaches its melting temperature and continues to absorb heat while melting. What happens to the temperature during this part of the process, and what is the absorbed energy doing?

A
The temperature rises because all added heat increases average kinetic energy.
B
The temperature falls because melting releases energy to the surroundings.
C
The temperature remains constant while added energy changes particle arrangement against attractions.
D
The temperature remains constant because no energy is absorbed during melting.

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1 point

A student claims that vaporizing water must break the O–H bonds because the sample changes from liquid to gas. Which correction best distinguishes a physical phase change from a change in chemical identity?

A
The water molecules normally remain intact; vaporization changes their arrangement and separation.
B
Each water molecule normally splits because the O–H bonds break during vaporization.
C
Water molecules become oxygen and hydrogen atoms because gas particles cannot retain bonds.
D
The chemical identity changes only if the vapor is produced below the boiling point.

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1 point

A phase diagram shows a liquid–gas boundary that terminates at a marked critical point. Which interpretation of that endpoint is correct?

A
At the critical point, solid, liquid, and gas coexist in equilibrium.
B
Above the critical point, only the gas phase can exist.
C
At the critical point, the solid–liquid boundary ends but the liquid–gas boundary remains.
D
At the critical point, the liquid–gas boundary ends; above the critical temperature and pressure, liquid and gas are not separated by a distinct boundary.

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1 point

F₂ and I₂ are both nonpolar molecules. Which explanation best accounts for their different room-temperature phases, with F₂ gaseous and I₂ solid?

A
F₂ has stronger dispersion forces because its smaller electron cloud is less easily distorted; it is solid while I₂ is gaseous.
B
I₂ has stronger dispersion forces because it has more electrons and a more easily distorted electron cloud; it is solid while F₂ is gaseous.
C
F₂ and I₂ have equal dispersion forces because both are nonpolar; both are gases at room temperature.
D
I₂ is solid because it forms hydrogen bonds, while F₂ is gaseous because it does not.

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1 point

Which interaction meets the stated criteria for hydrogen bonding: hydrogen must be bonded to N, O, or F and attracted to an N, O, or F atom with a lone pair on a neighboring particle?

A
A hydrogen atom in CH₄ is attracted to a nitrogen atom in a neighboring NH₃ molecule.
B
A hydrogen atom in HCl is attracted to a fluorine atom in a neighboring HF molecule.
C
A hydrogen atom bonded to oxygen in one H₂O molecule is attracted to a neighboring water molecule’s oxygen lone pair.
D
A hydrogen atom bonded to carbon in CH₃OH is attracted to a neighboring oxygen atom.

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1 point

When a Na⁺ ion is surrounded by water molecules in solution, how should the attraction between the ion and a water molecule be classified?

A
The attraction between Na⁺ and a polar water molecule is ion–dipole.
B
The attraction between Na⁺ and a polar water molecule is dipole–dipole.
C
The attraction between Na⁺ and a polar water molecule is hydrogen bonding.
D
The attraction between Na⁺ and a polar water molecule is London dispersion only.

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1 point

Two comparable liquids are at the same temperature. If one has stronger attractions between its particles, which statement best predicts its vapor pressure?

A
The liquid with stronger attractions has a higher vapor pressure because its molecules are held more closely together.
B
The two liquids must have equal vapor pressures because they are at the same temperature.
C
The liquid with stronger attractions has a higher vapor pressure because its surface molecules escape more readily.
D
The liquid with stronger attractions has a lower vapor pressure because fewer surface molecules escape into the gas.

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1 point

A liquid is at its boiling temperature under a certain external pressure. The external pressure is then raised while the liquid’s temperature is held fixed. What is the best prediction?

A
It will boil immediately because increasing external pressure increases the liquid’s vapor pressure.
B
It will not boil at that unchanged temperature; it generally must be heated to a higher temperature for its vapor pressure to match the higher external pressure.
C
It will boil at a lower temperature because increased external pressure makes particles separate more easily.
D
Its boiling temperature cannot change because boiling depends only on the liquid’s identity.

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1 point

At fixed pressure, a substance is melting at its melting temperature. Heat is added, but the temperature remains constant while melting continues. Which explanation best accounts for this observation?

A
The temperature rises because all added heat increases the particles’ average kinetic energy.
B
The temperature stays constant because the particles stop moving until the phase change is complete.
C
The temperature stays constant while energy is used to rearrange or separate particles against their attractions.
D
The temperature falls because particles release energy as they separate.

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1 point

An open container of liquid loses some molecules from its surface to the air, even though the liquid is below its boiling point. Which process is occurring?

A
The liquid is evaporating: surface molecules enter the gas even though the liquid is below its boiling point.
B
The liquid is boiling: any vapor formation means vaporization is occurring throughout the liquid.
C
The liquid is condensing: surface molecules leave the liquid and enter the gas.
D
The liquid is sublimating: liquid particles pass directly into the gas.

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1 point

A sample is brought above its critical temperature and critical pressure. Which conclusion about its liquid–gas behavior follows?

A
The solid, liquid, and gas phases must all coexist in equilibrium.
B
The liquid–gas boundary becomes a permanent separation between two phases.
C
The substance must be a gas because pressure cannot affect phase above the critical temperature.
D
There is no distinct boundary between liquid and gas.