Learning Outcomes
- State assumptions of the kinetic theory for ideal gases.
- Explain conditions for ideal gas behavior and limitations at high pressures/low temperatures.
- Use the general gas equation pV=nRT in calculations.
Gas Laws
- Physical condition of gases defined by: Pressure (p), Temperature (T), Volume (V), Amount of Particles (n).
- Pressure (p) is force per unit area; increases with number of molecules (n) and temperature (T).
Boyle's Law
- Volume (V) inversely proportional to pressure (p) at constant temperature: pV=extconstant.
- Experiments show: p1V1=p2V2.
Charles' Law
- Volume (V) directly proportional to absolute temperature (T) at constant pressure: VextaT;extV/T=extconstant.
Avogadro's Law
- Volume (V) directly proportional to amount of gas (in moles) at constant pressure and temperature.
- Volume ratios in balanced equations reflect mole ratios.
Ideal Gas Equation
- Derived from combining gas laws: pV=nRT.
- Important conversions: 1 atm = 760 mmHg = 101 kPa; 1 dm³ = 1000 cm³.
Gas Mixtures and Partial Pressures
- Dalton’s Law: Total pressure PT=PA+PB+….
- Partial pressure from mole fraction.
Deviations from Ideality
- Kinetic theory basis: gas particles do not exert forces, negligible volume, elastic collisions.
- Real gases deviate due to attractive forces and significant particle volume.
Conditions for Ideal Behavior
- High temperature: minimizes intermolecular forces.
- Low pressure: maximizes distance between particles, reducing attraction influence.