CHEM 112 Lecture Notes - Lecture 9: Boltzmann Distribution, Molar Mass, Ideal Gas

• School: Queen's University
• Department: Chemistry
• Course: CHEM 112
• Professor: Richard Oleschuk

Document Summary

Lecture 9: gases molecules (or atoms) are point mass particles (has mass but no volume) in constant, random straight-line motion, molecules are separated by great distances, molecules collide only fleetingly, no forces between molecules, no energy loss. Refer to speed(u), velocity independent of direction (=sum of velocity vectors) Measure individual speeds at a point in time, determine distribution. Determine median , average , as well as root-mean-square speed. Measured in speed of rotating disks (wipeout for molecules) The fraction of molecules was a particular speed f(u) Depends on speed(u) molar mass(m) and temperature (t, in kelvin) Can change t and m to see effect on distrubtion. The larger the mass we have, the smaller the speeds we get at a particular temperature. More temperature- more kinetic energy, and more distribution of speeds. Kinetic energy of any conventional particle in motion is known to be related to the particle mass, and the speed.