)the pressure in a gas container full of helium at 15°c is 200 barg. the container is a right cylinder with hemispherical ends such that the overall internal length is 1.8 m. the internal diameter of the container is 0.3 m. a) what mass of gas is in the container? b) what is the cost of helium (e per m@ 273.15 k and 1.0 atm.) if the price of the container is £150? answers a) 4.01 kg b) £6.68 m3 4) air may be assumed to be 21.0% v/v oxygen, 0.3%v/v carbon dioxide and 78.71 v/v nitrogen. evaluate the relative molar mass of air answers 28.898 kg kmol