Question

A gas mixture, has a total pressure of 300. Torr and consists of equal masses of Ne and Ar. What is the partial pressure of Ar, in Torr?

Answer 1

I would make up a convenient number (100 for example) and say the gas mixture consists of 100 g Ne and 100 g Ar.
Calculate moles of each.
Calculate total moles.
Calculate mole fraction of each.
Then PAr = mole fraction Ar x 300
PNe = moles fraction Ne x 300 = ??
Post your work if you get stuck.

Answer 2

100