A compressed gas cylinder contains 1.00 103 g of argon gas. The pressure inside the cylinder is 2096 psi (pounds per square inch) at a temperature of 19°C. How much gas remains in the cylinder if the pressure is decreased to 656 psi at a temperature of 27°C?

Answer 1

Convert 2097 psi to atm.
2097 psi/14.7 = ? atm
Convert 1000 g to mol Ar. mol = grams/molar mass.

Use PV = nRT, substitute and solve for V = volume.

Then reuse PV = nRT, substitute the new P, the old V, R, and new T and solve for n. Then n = grams/molar mass, you know n and molar mass, solve for grams.
Don't forget T must be in kelvin.