Question

3 mole of O2 mixed with 5 mole Argon at temperature T. Find total energy of system.

(1)12RT
(2) 19RT
(3) 15RT
(4) 10RT

Answer 1

Answer:

I think it's option 1 12rt

Answer 2

3 moles of O2 is mixed with 5 moles of Argon at temperature T.

We have to find the energy of system.

solution : O2 is diatomic molecule,

so, molar capacity at constant volume, Cv = 5R/2

Ar is monoatomic atom.

so molar heat capacity at constant volume, Cv' = 3R/2

using energy formula, ∆U = nCv ∆T

so, total energy of system = energy of O2 + energy of Ar

= nCvT + n'Cv' T

= 3 × 5R/2 × T + 5 × 3R/2 × T

= 15RT/2 + 15RT/2

= 15RT

Therefore the total energy of system is 15RT