An empty cylindrical canister 1.50m long and 90.0 cm in diameter is to be filled with pure oxygen at 22.0°C to store in a space station. To hold as much gas as possible, the absolute pressure of the oxygen will be 21.0 atm. The molar mass of oxygen is 32.0 g/mol.
a. How many moles of oxygen does this canister hold?
b. How many kilograms?