Task id12338

There are two volumes: in one N1=1019, and in the other N2=0.4•1019 molecules of the same gas. In the initial state, the internal energy of the first volume of gas was dU=1.9 J greater than that of the second. The volumes are brought into thermal contact. In the steady state, the average energy per molecule in the first volume decreased by 25%. What is the internal energy of the gas in the first volume in its initial state? Gas is ideal. There is no heat exchange with the external environment.