Kinetic Theory of Gases
Kinetic Theory of Gases gives good physical understanding to concepts presented in classical thermodynamics.
Significance of Kinetic Theory of Gases:
• The ideal gas equation of state can be derived from the kinetic theory of gases
• It should be noted that such a derivation has no bearing on classical thermodynamics.
• Recall, classical thermodynamics
1) does not depend on microscopic structure of matter
2) does not predict anything about microscopic features
• Why study kinetic theory in a course that focuses more on classical thermodynamics?
1) gives good physical understanding to concepts presented in classical thermodynamics (i.e. ideal gas assumption, definition of CP).
2) helps one understand why real gases behave differently from ideal gases.
Analysis: Let’s consider a monatomic gas and make the following assumptions:
1) The gas consists of an enormous number of molecules. All of the molecules are identical (assuming a pure gas).
2) The molecules are very small relative to the average distance between them. The volume occupied by the molecules themselves is a tiny fraction of the volume of the container.
3) The molecules fly about randomly in all directions—there is no preferred direction.
4) The molecules do not interact except when they collide.
5) Collisions of the molecules with each other and with the walls of the container are perfectly elastic.
6) The laws of macroscopic mechanics (Newton’s laws) apply to individual molecules.