Answer:
The answer to your question is: 2 grams of methane
Step-by-step explanation:
Data
V = 9.15 l
P = 1.77 atm
T = 57° C = 330 °K
Ar mass = 19 g
CH4 mass = ?
Formula
PV = nRT
Process
 

 

 

 n = 0.6 
Argon
 40 g of Ar -------------------- 1 mol
 19 g --------------------- x
 x = 0.475 mol of Ar
moles of CH4 = 0.6 - 0.475
 = 0.125
 
Methane
 16 g of CH4 --------------- 1mol
 x ---------------- 0.125 mol
 x = 2 grams