Answer:
The mass of Ar is 36.91g
Step-by-step explanation:
The gas mixture consist of Neon(Ne) and Argon(Ar)
Partial pressure of Ar = total pressure of mixture - partial pressure = 4 - 0.3 = 3.7 atm
Mole fraction of Ar = partial pressure of Ar ÷ total pressure of mixture = 3.7/4 = 0.925
Mass of Ar = 0.925 × molecular weight of Ar = 0.925 × 39.9 = 36.91g