Two tanks are connected by a valve. One tank contains 2 kg of an ideal gas at `77^(@)C` and 0.7 atm pressure. The other tank has 8kg of same gas at `27^(@)C` and 1.2 atm pressure. The valve is opened and the gases are allowed to mix. The final equilibrium temperature was found to be `42^(@)C`.
(a) Find the equilibrium pressure in both tanks.
(b) How much heat was transferred from surrounding to the tanks during the mixing process. Given: `C_(v)` for the gas is `0.745 KJ kg^(-1) K^(-1)`.

Answer

(a) `1.05 atm` , (b) `37.25 KJ`