A gaseous mixture contains 434.0 Torr H 2 ( g ) , 434.0 Torr H2(g), 389.9 Torr N 2 ( g ) , 389.9 Torr N2(g), and 77.9 Torr Ar ( g ) . 77.9 Torr Ar(g). Calculate the mole fraction, χ , χ, of each of these gases.