A certain sample of gas has a volume of 500 ml. at a pressure of 1.5 atmosphere.What will be its volume if the gas is submerged toa pressure of 5 atmosphere at constant temperature?

Answer 1

P1 V1 = P2 V2
so
V2 = P1 V1/P2

I am assuming that these are total pressures and no "gage" pressures. If they are gage pressures add 1 atm to both P1 and P2