Density and molar mass of gases 0.96 g of a gas occupies a volume of 0.672L at STP (0°C and 1atm). What is the identity of the gas: O N2 or CO2? gas: O2, d MMx RT 4. Effusion If 1 mol of CO2 effuses in 250 seconds, how long will it take Cl2 gas to effuse at the same temperature?
