Q.

A gas mixture consists of 2 moles of oxygen and 4 moles of neon at temperature T. Neglecting all vibrational modes, the total internal energy of the system will be        [2023]

1 8 RT  
2 16 RT  
3 4 RT  
4 11 RT  

Ans.

(4)

(Cv)max=n1Cv1+n2Cv2n1+n2

(Cv)max=2×52R+4×32R2+4=11R6

ΔU=n(Cv)mixΔT=6×11R6×ΔT=11RT