Heat of Fusion and Vaporization Lecture Notes

Flashcards covering Vocabulary

Heat of Fusion

The amount of energy needed for a substance to melt or freeze under constant pressure; specifically a solid to liquid relationship.

Melting

The phase change of a substance from a solid to a liquid.

Freezing

The phase change of a substance from a liquid to a solid.

Heat of Vaporization

Describes the amount of energy needed for a given substance to either boil or condense under constant pressure.

Boiling

Phase change from liquid to gas.

Condensing

Phase change from gas to a liquid.

Latent Heat

Energy that is not utilized to change the temperature.

Melting Point

The temperature at which a substance melts or freezes.

Boiling Point

The temperature at which a substance boils.

Molar Heat of Fusion

The amount of heat energy that needs to be absorbed or released for one mole of a substance to undergo a solid to liquid phase change.

Molar Heat of Vaporization

The amount of energy that needs to be absorbed or released from one mole of a substance to boil or condense.

Critical Point

The temperature and pressure needed for a given substance in order for its liquid and gaseous phases to be indistinguishable from each other.

Supercritical Fluid

A state of matter where the distinction between liquid and gas phases is indistinguishable, occurring beyond the critical point.

Triple Point

The temperature and pressure at which all three states of matter (solid, liquid, gas) coexist in equilibrium.

Change in Enthalpy

Delta H; latent heat of fusion is equal to the delta h divided by the molar mass