11.11.2013
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Postulates of Kinetic Molecular Theory
1. A gas is made up of vast number of particles, and these
particles are in constant random motion
İmage source: http://www.docstoc.com/docs/113002286/Kinetic-Molecular-Theory
2. Particles in a gas are infinitely small, they occupy no
volume
Postulates of Kinetic Molecular Theory
Volumeless - Most of the volume occupied by a gas is empty space
•Accounts for lower density compared to solid and liquids.
•Accounts for compressibility of gases.
Postulates of Kinetic Molecular Theory
3. Particles in a gas move in straight lines exc ept when they
collide with other molecules or with the walls of the
container. All collisions are elastic, so that the total
kinetic energy of the particles is conserved
İmage source: http://en.wikipedia.org/wiki/Kinetic_theory
Postulates of Kinetic Molecular Theory
4. Particles in a gas interact with each ot her only when
collisions occur.
•Assumes no force of attraction/repulsin between gas particles
Postulates of Kinetic Molecular Theory
5. The average kinetic energy of the particles in a gas is
proportional to the absolute temperature of the gas and
does not depend on the identity of the gas
The average Kinetic Energy of gas particles depends on
Temperature of the gas:
TKEav
Maxwell-Boltzmann Speed Distributions
