Unit B: Gasses- Section 4.3-4.4

Molar Volume of Gas & The Ideal Gas Law

Molar Volume is the same for all gasses with:

The same temperature & pressure

At STP, Molar Volume =…?

22.4 (101.325 kPa & 0 C)

At SATP, Molar Volume =…?

24.8 (100 kPa & 25 C)

n=

Volume x 1mol/L / mol (STP/SATP)

V=

n/mol x L/mol / 1mol

Molar Volume

The volume that one mole of a gas occupies at a specified temperature and pressure

Real Gas

-Does not follow gas laws exactly, it deviates at low temperatures and high pressures

Real Gas

-Condenses to a liquid or sometimes a solid when cooled or under pressure

Real Gas

-Particles are attracted to eachother and have volume

Real Gas

-Behaves like an ideal gas at higher temperatures and lower pressures

Ideal Gas

-Does NOT condense when cooled

Ideal Gas

-Assumes that the particles have no volume and are not attracted to eachother

Ideal Gas

Follows all gas laws perfectly under all conditions

Ideal Gas molecule behavior

The molecules collide like perfectly hard spheres, rebound very quickly after collision

Real Gas molecule behavior

Molecules are “soft” (can be deformed), so collisions take longer