gases and the gas laws

gas

Fills a container, taking on the shape of the container. Molecules are widely spaced, motion is chaotic, and disorder is at a maximum. Interparticle interactions are minimal.

liquid

Occupies a fixed volume, does not fill a container, does take on the shape of the container. Molecules continue to undergo translational motion but are in much closer proximity.

solid

Rigid material, does not fill a container. Does not assume the shape of the container. There is a high degree of order among the structural particles; the motion of the particles is vibrational.

Boyle’s law

for a fixed amount of gas at a given temperature the volume of a gas is inversely proportional to the pressure, P1V1 = P2V2

Charles’s law

the ratio of volume and temperature for a fixed mass of gas remains constant, provided the external pressure is not altered

Avogadro’s law

a gas containing 1 mole of He molecules occupies the same volume as a gas containing 1 mole of CH4 molecules at a constant T and P

Dalton’s law of partial pressure

the pressure of a mixture of gases is the sum of the partial pressures of the various component gases

the mole fraction

quantifies the proportion of each component of a mixture

strategy for Dalton’s law

1. Determine the moles present of each gas

2. Calculate the mole fraction of each gas

3. Calculate the partial pressures