AP Chemistry : Properties of Liquids

Study concepts, example questions & explanations for AP Chemistry

varsity tutors app store varsity tutors android store

Example Questions

Example Question #18 : Thermodynamics And Phases

If you create a perfect vacuum and place a glass of water into the vacuum at room temperature, what will happen to the water?

Possible Answers:

The water will boil very rapidly and then stop

The water will freeze

Nothing will happen

The water will float about the vacuum

The water will boil

Correct answer:

The water will boil

Explanation:

Boiling occurs when the vapor pressure exceeds the air pressure. There is no air pressure in a vacuum, so water at any temperature will boil in a vacuum.

Example Question #19 : Thermodynamics And Phases

Boiling points at standard temperature and pressure:

Methanol-

Toluene-

Water-

Methylene chloride-

Dimethylsulfoxide-

Of the five compounds given, which will have the highest vapor pressure at standard temperature and pressure?

Possible Answers:

Toluene

Dimethylsulfoxide

Water

Methylene chloride

Methanol

Correct answer:

Methylene chloride

Explanation:

A liquid will boil when its vapor pressure increases to match the pressure of its environment. By this logic, a liquid with a higher vapor pressure will be closer to boiling. Liquids with low boiling points thus have greater vapor pressures.

Of the given compounds, methylene chloride has the lowest boiling point, meaning it will also have the highest vapor pressure.

Example Question #1 : Properties Of Liquids

Oil and vinegar is a very popular salad dressing. It also is commonly used for dipping bread. The main component of the oil phase is olive oil, while the main part of the vinegar portion is aqueous acetic acid.

When oil and vinegar salad dressing is allowed to stand at room temperature, two distinct phases are observed. The main explanation for this phenomenon is the difference in _________ of the two phases.

Possible Answers:

density

acidity

solubility

buoyancy

polarity

Correct answer:

polarity

Explanation:

Olive oil, like most oils, is non-polar, while aqueous acetic acid is very polar. These two phases do not mix because of their different solvent polarities.

Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: