Equilibrium and Phase Changes Quiz

Equilibrium is characterized by

• opposing processes occurring at equal rates.

• an open system.

• net change in the amount of substance in one phase.

• changes in physical states.

The process of changing from a solid to a gas is known as

• condensation.

• sublimation.

• deposition.

• vaporization.

Which of the following liquids is most volatile?

• water

• ether

• molten salt

• skim milk

A phase is defined as any part of a system that has

• the same composition throughout.

• the same properties throughout.

• the same properties and composition throughout.

• the same temperature throughout.

Dry ice sublimes into carbon dioxide gas. If the proper conditions are maintained and the system is closed, the dry ice and the carbon dioxide gas will eventually

• become the same phase.

• reach equilibrium.

• stop changing phase.

• Both (a) and (b)

If the vapor pressure of water is 4.25 kPa at 30.0°C, the vapor pressure of water at 10.0°C is most likely to be

• 0 kPa.

• 1.23 kPa.

• 4.25 kPa.

• 12.34 kPa.

The temperature at which the vapor pressure of a substance equals atmospheric pressure is its

• boiling point.

• critical point.

• melting point.

• triple point.

The amount of energy needed to melt one mole of a substance is its molar

• enthalpy of fusion.

• enthalpy of vaporization.

• entropy of fusion.

• entropy of vaporization.

The point on a phase diagram that indicates the temperature and pressure conditions at which the solid, liquid, and vapor of the substance can coexist at equilibrium is known as the

• critical point.

• phase point.

• triple point.

• equilibrium point.

Assume you have a substance that plots right on the liquid-vapor equilibrium line on its phase diagram. If you raise the temperature slightly and keep the same pressure, the substance will now be

• a solid.

• a liquid.

• a gas.

• on a different equilibrium line.