Chemistry 2214A/B Lecture Notes - Lecture 3: Excluded Volume, Ideal Gas, Molar Mass

• School: Western University
• Department: Chemistry
• Course: Chemistry 2214A/B
• Professor: T.K.Sham

Document Summary

In thermodynamics, we deal with the macroscopic properties of the whole system containing all the molecules, that is why we need which is the internal energy, u, of the system at a given. Root mean-square speed: c2 = = 3rt/m, so rms speed is c = (3rt/m) Assuming ideal behaviour, (a) calculate the average kinetic energy for he (m = 4 gmol-1) and ar (m = 40 gmol-1) in kjmol-1 at 25 c; (b) calculate the rms speed of he and ar at 25 c. Average kinetic energy depends on t only, so: = (3/2) (a) Rt = (3/2) 8. 314(298. 15) = 3. 718 kjmol-1 (b) k/4 gmol-1) = 1. 859 kjg-1 che = 1. 859 kjg-1 = 1. 859 x 106 m2s-2 = 1363 ms-1. For he: che = (3rt/mhe) = (3 x 8. 314 jk-1mol-1 x 298. 15: = 185. 91 kjg-1 = 1. 8591 x 108 m2s-2 = 13635 ms-1.