AP Chem Gases

Ideal gases

Imaginary gases that perfectly fit all the assumptions of the kinetic molecular theory

Kinetic Molecular Theory

Volume of particles assumed to be negligible

Collisions between gas particles and between particles and the walls of the container are elastic collisions

There are no forces of attraction between gas particles

The average kinetic energy of gas particles depends on temperature, not on the identity of the particle

Ideal gas law

PV=nRT

P: pressure (atm)

V: volume (Liters)

n: moles

R. 0.08206 L(atm)/mol(k)

T: temperature in kelvin

The nature of gases

They expand to fill their containers

Their fluid has low density

compressible

effuse and diffuse

Barometer

The first device designed by Evangelista Torricelli to measure atmospheric pressure

Standard Temperature and Pressure (STP)

P = 1 atmosphere = 760 torr = 101.325 kPA

T: 273.15 Kelvins

The molar volume of an ideal gas is 22.4 liters at STP

Boyle's Law

Pressure is inversely proportional to (T is constant)

P1V1 = P2V2

Charle's Law

The volume of a gas is directly proportional to temperature, and is zero at zero Kelvin (P is constant)'

P1V1 = P2V2

Gay Lussac's law

The pressure and temperature of a gas are directly related ( V is constant)

P1/T1 = P2/T2

Combined gas law

the relationship between the pressure, volume, and temperature of a fixed amount of gas

P1V1/T1 = P2V2/T2

Avogadro's Law

For a gas at constant temperature and pressure, the volume is directly proportional to the number of moles of gas

V1n1 = V2n2

Density and the Ideal Gas Law

D = MP/RT

M: Molar mass

P: Pressure

R: Gas constant

T: Temperature in Kelvin

Dalton's Law of Partial Pressures

P total = P1 + P2 + P3 …

Diffusion

describes the mixing of gases.

The rate of gas mixing

Effusion

Describes the passage of gas into an evacuated chamber

Graham's Law

Rate 1/Rate 2 = √M2/M1