Question

The kinetic molecular theory establishes an important link between macroscopic and microscopic quantities. The most important link is probably between temperature (T) and average kinetic energy of molecules.

a. For He gas, compute the average velocity of the atom at the temperature of 25^oC.

b. If He is replaced by Ar, what will be the corresponding velocity?

c. It is known that the velocity of the gas molecules is not uniform, but conform to the MaxwellBoltzmann distribution. Depict graphically the velocity distributions of the two gases as a function of the velocity.

If temperature is lowered, indicate in the plot which direction would the peaks move.

Answer 1

M 4 a/mo Cab T- 298 K He 1 R=8.31 Tmot k 19 5ms 3x 8.31 x 298 /hovo) Vns 1363.8 40 MAT (6) 19ms As JM Vms He MAT MHo x A He Jo om 136R-8 xI JTo 19pmy 430 96 15

-mc2 C)= 47c2 2RET IMarwell) e) Kx x emks k k2Censtant thiequation TT7 T at He , and A Samme T He velouty at diffoent ak temperatin 4 T (T27 T 2 A T TI Tr Tr velouty Peak ullmove am yfemperatue dawere e TaT sght direction