6.73 L
This one requires the combined gas law.
P1V1/T1 = P2V2/T2
P1 = 150 kPa = 1.48 atm
V1 = 5 L
T1 = 300 K
P2 = 1 atm
V2 = This is what we’re solving for.
T2 = 273 K
P2 and T2 are based on the conditions of STP. I also changed P1 to atm to keep the units consistent.
Solve the equation for V2:
V2 = P1V1T2 / T1P2
V2 = (1.48 atm)(5 L)(273 K) / (300 K)(1 atm) = 6.73 L