CHEM 205 Lecture Notes - Lecture 2: Diatomic Molecule, Internal Energy, Ideal Gas
Document Summary
Kmt: molecules in random motion, gas molecules infinitely small points, molecules move in straight lines until they collide, molecules don"t interact with each other, all collisions are elastic f. The first three are functions of temperature only: utrans=ke, at normal temperatures around 300k, we know from our derivations that, utrans=3/2nrt where n is the number of moles. Before in our derivation, we only had rt since we stated n as 1 mol. The point is that in real gases, not only t has effect on internal energy, but volume also affects it (intermolecular forces). Also molecules aren"t infinitely small: v (v-nb) where n=# of moles, b=volume/mole occupied by the gas, attractive forces: molecules attracted to each other proportional to gas density. Observed pressure will be less than ideal: p (p+an^2/v^2). But i do know why an^2/v^2 is added not subtracted. P is always positive if pressure exerted on system.
