Chapter 12 Chemistry Test

Phase diagram

A graph showing the relationship between the states of a substance at various temperatures and pressures

Effusion

A process by which gas particles pass through a tiny opening

Barometer

An instrument designed to measure atmospheric pressure

Condensation

As molecules lose heat, they lose kinetic energy and speed, causing them to come closer together

The partial pressure of a gas depends on

Concentration of the gas, identity of the gas, temperature of the gas

True or False? During effusion, a gas escapes through a tiny opening into a vacuum

False

True or False? Lighter gas particles diffuse less rapidly than do heavier gas particles

False

True or False? The density of a gas decreases as its compressed

False (Increases)

Pressure

Force per unit of volume

Deposition

Gas turns to a solid without entering the liquid phase inbetween

Vaporization

Molecules gain such large amounts of kinetic energy from heating up they become a gas

Evaporation

Molecules move and shake so much from being heated they escape to the atmosphere as a vapor

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Sublimation

Solid turns to a gas without entering the liquid phase

Freezing

Temperature at which a liquid is converted into a crystalline solid

Melting

Temperature at which the forces holding a crystalline lattice together are broken

Boiling

Temperature at which the vapor pressure of a liquid equals the external or atmospheric pressure

Vapor pressure

The vapor above a liquid inside of a sealed container

True or False? A gas can flow into a space occupied by another gas

True

True or False? Gases are less dense than solids because there is a lot of space between the particles of a gas

True

True or False? The diffusion of a gas is caused by the random motion of the particles of the gas

True

True or False? The diffusion of a gas is caused by the random motion of the particles of the gas.

True

True or False? The random motion of gas particles causes a gas to expand until it fills its container

True

What causes a liquid to boil?

When its vapor pressure = external pressure

The height of a liquid in a barometer is affected by

altitude, atmospheric pressure, and density of the liquid

Kinetic molecular theory

describes the behavior of gases in terms of particles in motion

Ionic solids have a (higher/lower) boiling point than molecular solids

higher

A line between two phases shows

the conditions of temperature and pressure at which phase changes are occuring

Critical point

the temperature and pressure at which the gas and liquid states of a substance become identical and form one phase (a substance cannot become a gas ta this phase)

Triple point

the temperature and pressure conditions at which the solid, liquid, and gaseous phases of a substance coexist at equilibrium