HANNAHGRACE9611GO HANNAHGRACE9611GO Chemistry Answered The mass of 560 cm3 (at STP) of an unknown gas is 1.60 g. This gas could be a. carbon dioxide (44 g/mol) b. hydrogen (2 g/mol) c. sulfur dioxide (64 g/mol) d. chlorine (71 g/mol) e. oxygen (32 g/mol)