Answer:
516.77 grams of Argon gas is present
Explanation:
Using the gas formula
PV = nRT
number of moles (n) = mass / molar weight or mass
P = pressure = 3.4 atm
V = volume = 72 L
R = gas constant = 0.082 L atm mol^-1 K^-1
T = temperature = 225 K
MM = molar mass of Ar = 38.984 g/mol
PV = mRT/ MM
m = PV MM / RT
m = 3.4 * 72 * 38.948 / 0.082 * 225
m = 9534.4704 / 18.45
m = 516.77 grams
the mass of Ar gas you have is 516.77 grams.