# 10.2 Gas Laws Including the Ideal Gas Law

PRE-HEALTH PREP

## Gas Laws

GAS LAWS
Boyle’s Law
(constant n, T)
PV = constant      or      P1V1 = P2V2      or      P ∝ 1/V

Charles’ Law
(constant n, P)
(constant T, P)
Combined Gas Law

Better Combined Gas Law

Ideal Gas Law

## Kinetic Molecular Theory (Ideal Gas Theory)

Kinetic Molecular Theory (Ideal Gas Theory)
1  Gas molecules have negligible volume.
2  Gas molecules don’t have any attractive forces between themselves.
3  All collisions are elastic (no loss of kinetic energy).
4  A gas is composed of a large number of atoms/molecules in random motion.
5  KEavg ∝ T           (KEavg = 3 / 2 RT)
Ideal Behavior
1. Gases behave more ideally at low Pressure and high Temperature.
2. Gases with less Intermolecular Forces tend to behave more ideally.

## Ideal Gas Law

PV = nRT          R  =0.08206 L.atm/mol.K

What is the volume of 2 moles of argon gas behaving ideally at a temperature of 298K and a pressure of 2.0atm?

What is the volume of 80g of argon gas behaving ideally at a temperature of 25°C and a pressure of 1520torr?

## RMS Speed

What is the root mean square speed of O2 gas molecules at 273K?