A gas mixture consists of 2 moles of oxygen and 4 moles of argon at temperature T. Neglecting all vibrational modes, the total internal energy of the system is

Explanation

Total internal energy of system
`=U_("oxygen")+U_("argon")=mu_(1)(f_(1))/(2)RT+mu_(2)(f_(1))/(f_(2))RT`
`2(5)/(2)RT+4(3)/(2)RT=5RT+6RT=11RT`
[As `f_(1)=5` (for oxygen) and `f_(2)=3` (for argon)]