A 0.465 g sample of an unknown compound occupies 245 ml at 298 k and 1.22 atm. what is the molar mass of the unknown compound? answer: a 0.465 g sample of an unknown compound occupies 245 ml at 298 k and 1.22 atm. what is the molar mass of the unknown compound? 26.3 g/mol 81.8 g/mol 33.9 g/mol 38.0 g/mol 12.2 g/mol