Question

A gas mixture consists of 3 moles of oxygen and 5 moles of argon at temperature T. Assuming the gases to be ideal and the oxygen bond to be rigid, the total internal energy (in units of RT) of the mixture is :

(1) 15

(2) 13

(3) 20

(4) 11

Comments

Kinetic theory of gases, behaviour of gases

Answer 1

Ans. (1) 15

Sol. ${f_1n_1Rt_1\over2}+{f_2n_2Rt_2\over2}=3\times{5\over2}RT+{5\over2}\times3RT=15$