Gas Laws and Kinetic Molecular Theory Overview

Kinetic Molecular Theory (KMT)

Explains gas behavior based on particle motion.

Assumptions of KMT

Gas particles are in constant, random motion.

Forces between gas particles

Gas particles experience negligible attractive or repulsive forces.

Motion of gas particles

Gas particles move freely and collide elastically.

Elastic collision

Collision where total kinetic energy remains constant.

Kinetic energy determinant

Depends on mass and velocity of the particle.

Kinetic energy distribution

Particles in a gas have varied kinetic energies.

Temperature

Measure of average kinetic energy of particles.

Low density of gases

Gases have large spaces between particles.

Compressibility of gases

Gases can be compressed due to particle spacing.

Expansion of gases

Gases fill containers due to particle motion.

Flow of gas particles

Gas particles can slide past each other easily.

Diffusion

Movement of gas particles from high to low concentration.

Effusion

Gas escaping through a tiny opening.

Diffusion and mass

Lighter particles diffuse faster than heavier ones.

Balloon expansion

Increased air pressure causes balloon to expand.

Boyle's Law

Pressure inversely related to volume at constant temperature.

Boyle's Law formula

P1V1 = P2V2.

Boyle's Law variables

Pressure (P) and volume (V) are variables.

Constant in Boyle's Law

Temperature remains constant.

Graph of Boyle's Law

Pressure vs. volume graph is hyperbolic.

Charles' Law

Volume directly related to temperature at constant pressure.

Charles' Law formula

V1/T1 = V2/T2.

Charles' Law variables

Volume (V) and temperature (T) are variables.

Constant in Charles' Law

Pressure remains constant.

Temperature in Charles' Law

Temperature must be in Kelvin.

Graph of Charles' Law

Temperature vs. volume graph is linear.

Gay-Lussac's Law

Pressure directly related to temperature at constant volume.

Gay-Lussac's Law formula

P1/T1 = P2/T2.

Gay-Lussac's Law variables

Pressure (P) and temperature (T) are variables.

Constant in Gay-Lussac's Law

Volume remains constant.

Temperature in Gay-Lussac's Law

Temperature must be in Kelvin.

Graph of Gay-Lussac's Law

Temperature vs. pressure graph is linear.

Combined Gas Law formula

P1V1/T1 = P2V2/T2.

Units for Combined Gas Law

Pressure, volume, and temperature units vary.

Constant in Combined Gas Law

Amount of gas remains constant.

Ideal Gas Law formula

PV = nRT.

Ideal Gas Law variables

Pressure (P), volume (V), n, R, temperature (T).

R in Ideal Gas Law

Ideal gas constant, 0.0821 L·atm/(K·mol).

Density calculation

Density = mass/volume using ideal gas law.

Ideal gas definition

Gas that follows gas laws perfectly under all conditions.

Molar mass calculation

Use density, temperature, and pressure to find molar mass.