Three 3.0 L sealed flasks , each at a pressure of 878 mmHg contain He, Ar, and Xe respectively. a) which of the flasks contain the greatest number of moles of gas? b) which of the flasks contain the greatest mass of gas? c) If He flask was heated and Ar flask was cooled, which of the three flasks would be at the highest pressure? d) If the temperature of the He was lowered while the Xe was raised, which of the three gases would have the greatest kinetic energy?