A 2l bottle contains a gaseous mixture of helium and oxygen (Oβ). the temperature and total pressure of the gaseous mixture in the bottle is 30c and 1atm, respectfully. if the density of the oxygen gas in the mixture is 0.521 g/l, what is the partial pressure of the helium gas in atm? note that the ideal gas constant is 0.08206 (l*atm)/(mol*k).