Question

A gas mixture contains each of the following gases at the indicated partial pressures: , 221O2torr , N2,131 torr; and He 131 torr
What mass of each gas is present in a 1.30 - L sample of this mixture at 25.0 degrees C?

Answer 1

actually the trick is that they have already given partial pressures you dont need to calculate mole fraction, total pressure is equal to sum of partial pressures-
for mass, you just use PV=nRT here p is partial pressure, and calculate each ones mass

Answer 2

using PV=nRT,u have to determine the Mm of each gas