Two tanks are connected by a tube $10$ mm in diameter and $0,9$ m long. One tank contains nitrogen and one tanks contains co$.$ The pressure and temperature are maintained at $350$ kPa and $30\backslash$deg C$.$ The difusivity is $0,08$ cm$^2/$s$.$ At some initial time, t$=0$ diffusion occurs between two tanks. After a while, the mole fraction of the nitrogen reachs $0,7$ on one end $0,49$ at the other end Determine the molar average velocities of the mix