Kinetic Molecular Theory ✏ Chemistry In a Nutshell

Rucete ✏ Chemistry In a Nutshell

1. Assumptions of Kinetic Molecular Theory

KMT explains the behavior of gases based on the motion of gas particles. The key assumptions are:

1. Gas particles are in continuous, random motion.
2. Gas particles have negligible volume compared to the total volume of the container.
3. No intermolecular forces (no attraction or repulsion between particles).
4. Collisions between gas particles are perfectly elastic, meaning no energy is lost.
5. The average kinetic energy (KE) of gas particles is directly proportional to absolute temperature (K).
• Formula:$$K{E}_{\text{avg}}=\frac{3}{2}kT$$
• $k$ = Boltzmann constant
• $T$ = Temperature in Kelvin

2. Key Relationships in Kinetic Molecular Theory

• Higher Temperature → Faster Particle Motion
• Higher Pressure → More Frequent Collisions
• Lighter Gas Molecules Move Faster than heavier molecules (Graham’s Law).

3. Application of KMT

• Explains gas laws (Boyle’s, Charles’, Avogadro’s).
• Describes diffusion and effusion behavior (faster for lighter gases).
• Used to justify the Ideal Gas Law:$$PV=nRT$$
  

In a nutshell

• Tiny particles move randomly.
• No intermolecular forces.
• Energy depends only on temperature.