Answer:
1.25L
Explanation:
Applying Gay-Lussac's Law which states that the pressure of a given mass of gas varies directly with the absolute temperature of the gas, when the volume is kept constant.
[tex]p_1v_1=p_2v_2\\\\5l\times 1.00atm=4.0atm\tiimes x\\\\x=5/4=1.25L[/tex]
Hence the volume at 4.0atm is 1.25L