Consider the following data for air trapped in a flask: pressure = 0. 988 atm room temperature = 23. 5°c volume of the flask = 1. 042 l from this calculation, assume air is 78. 5% nitrogen and 21. 5% oxygen (by number of moles). R = 0. 0821 l•atm•mol-1•k-1 n = 14. 01 g/mol o = 16. 00 g/mol what is the mass of air in the flask?.