. The gas mixture constists of 3 moles of oxygen


and 5 moles of argon at temperature T . Considering only translational and rotational modes, the total internal energy of the system is:

A: 12 RT

B: 20 RT

C: 15 RT

D: 4 RT

 

Best Answer

Explanation

The gas mixture constists of 3 moles of oxygen and 5 moles of argon at temperature T

Internal energy formula-

U=fnRT2f is degree of freedom

Degree of freedom for Oxygen = fo = 3+2 = 5

Degree of freedom for Argon = fa = 3

Total Internal Energy = Internal Energy due to oxygen + Internal Energy due to argon

U= Uo + Ua

U=fo n2 RT2+ fa n2 RT2

U=RT(fo n2 2+ fa n2 2)

Putting given values

U=RT(5 3 2+ 3 5 2)

U = 15 RT

Final Answer

Hence, Correct option is C: 15 RT

 

 

Talk to Our counsellor