Question

3. 30 pts Take-home problem, and turn in on Monday 10/28 before class. A mixed gas has 20% of N, and 80% of Xe. It is at room temperature (T = 300 K the total pressure is 105 Pa. Radius of N2 molecules is IN, = 1.55 x 10-10 m, and radius of Xe atoms is rxe = 2.16 x 10-10 m. Mass values are mN, = 28 x 1.66 x 10-27 kg and mxe = 139 x 1.66 x 10-27 kg. (a) Calculate the average time between collisions among the molecules/atoms. (b) What is the thermal conductivity of the mixed gas? For both questions, express your answers in equation first, and then calculate the numer- ical values.

Answer 1

collision himet Mean poth Vyd A RT Viny Ja td NAP M = 0.2728 70.87139 R2 = 1.55 x 100m : 116.8 Rre = 2.16 x 100m Averou R: (1.55x0.212.16x0.9), 40 70.270.87 = 2.038x100m a = 1.38X1070 x 300 TRT (4.0764 10-to) XR 105 ne 414 x 10-23 - 5.613x10 VIT 16.61 x 10"! m Ving: 3x8.31 x 300 116.8 8m18 collision 0.701x10 sec time : 5.613x10-8m 8 m/s