An unknown gas effuses through a pin-hole in a container at a rate of 7.2 mmol/s. Under the same con — Gases Chemistry Question

An unknown gas effuses through a pin-hole in a container at a rate of 7.2 mmol/s. Under the same conditions gaseous oxygen effuses at a rate of 5.1 mmol/s. What is the molar mass (in g/mol) of the unknown gas?