Question

What volume will 12.0 g of oxygen gas occupy at 25 degrees celcius and a pressure of 52.7 kPa?

Answer 1

Use PV = nRT. n = number of mols = grams/molar mass. Remember T must be in kelvin and note the correct spelling of celsius. I would convert kPa to atm but that isn't absolutely necessary if you use the correct R as a constant.