Answer:
 V = 81.86 L
Solution:
Data Given;
 P = 1.19 atm
 n = 4.78 mol
 T = 251 K
Let suppose the gas is acting ideally, then according to Ideal Gas Equation,
 P V = n R T
Solving for V,
 V = n R T / P
Putting Values,
 
 V = (4.78 mol × 0.0812 L.atm.mol⁻¹.K⁻¹ × 251 K) ÷ 1.19 atm
 V = 81.86 L