Changes of State and the Gas Laws

Flashcards on Changes of State and the Gas Laws

Melting/Fusion

Transition from solid to liquid

Freezing

Transition from liquid to solid

Vaporization/Evaporation

Transition from liquid to gas

Condensation

Transition from gas to liquid

Sublimation

Transition from solid to gas

Deposition

Transition from gas to solid

Vaporization

Energy transferred from surrounding to substance evaporating; Increases kinetic energy of liquid molecules; Disrupts intermolecular forces of attraction; Molecules enter gas phase

Evaporation

Change from liquid to gas phase below boiling point; Endothermic, requires ΔHvap

Melting Point

Temperature at which a substance undergoes phase change from solid to liquid

Boiling Point

Temperature at which a substance undergoes phase change from liquid to gas

Heat of Fusion (ΔHfus)

Amount of energy required to melt a solid at its melting point (or energy removed to freeze a liquid)

Heat of Vaporization (ΔHvap)

Amount of energy required to boil a liquid at its boiling point (or energy removed to condense a gas)

Specific Heat

Amount of heat required to raise the temperature of 1 g of the substance by 1 °C

Pressure

Force per unit area

Boyle's Law

Pressure and volume are inversely proportional when n and T are constant.

Charles's Law

Volume and temperature are directly proportional when n and P are constant.

Gay-Lussac's Law

Pressure and temperature are directly proportional when n and V are constant and T is given in kelvins

Avogadro's Law

Moles of gas, n, is directly proportional to volume, V, of the gas (constant T and P).

Dalton's Law of Partial Pressures

The total pressure of a gas mixture is equal to the sum of the partial pressures of each gas in the mixture.

Henry's Law

Number of moles of gas, n, dissolved in a liquid is directly proportional to the partial pressure, P, of the gas.

Sublimation

Heat absorbed from surroundings during phase change from solid to gas

Deposition

Heat released to surroundings during phase change from gas to solid

Molar volume of a gas at STP

22.4 L

STP

Standard temperature and pressure: 0 °C (273.15 K) and 1 atm of pressure