
William W. answered 12/05/20
Math and science made easy - learn from a retired engineer
You don't describe the cylinder, but I have to guess, based on the verbiage in the question, that this is some sort of a flexible wall cylinder, perhaps something with a piston-type configuration that allows it to grow as needed to keep the pressure constant.
The Ideal Gas law say PV = nRT or PV/T = nR
If we have a confined condition (no gas comes in or leaves), then we can say that "nR" never changes meaning that P1V1/T1 = P2V2/T2 and, if we know that P1 and P2 are equal then:
V1/T1 = V2/T2 or V1/V2 = T1/T2
But we MUST use Kelvin as the unit of temperature so T1 = 293 + 273.15 = 566.15 K and T2 = 674 + 273.15 = 947.15 K therefore:
V1/V2 = 566.15/947.15 = 0.598