The gaseous mixture contains 414.0 torr of h2(g), 345.7 torr of n2(g), and 80.1 torr of ar(g). Then, total pressure of the gas would be: 414 torr + 345.7 torr + 80.1 torr= 839.8 torr
The mole fraction of each gas:
H2= 414 torr/839.8 torr= 0.49
N2= 345.7 torr/839.8 torr= 0.41
Ar= 80.1 torr/839.8 torr= 0.10