* The molar mass of dioxygen (O₂)? In this case, the answer is 32 g/mol. This is because oxygen has an atomic mass of 16 g/mol, and dioxygen has two oxygen atoms (O₂).

* The mass of a specific quantity of dioxygen? In this case, you would need to provide the quantity, such as grams, moles, or liters (at a specific temperature and pressure).

Please clarify your question to get a more specific answer.