I'm stumped again :(

the question is - A gas sprayed from an aerosol can effuses 5.06 times slower than oxygen.If the molar mass of oxygen is 32.g/mol, what is the molar mass of the unknown gas?

I don't know if I am doing the ideal gas law or grahams law or how to set it up. Please help. Thanks

3 answers

Graham's Law is what you want.
rate 1/rate 2 = (sqrt molar mass 2/sqrt molar mass 1)
so what would be rate 1 and 2?
Make up a number for the rate of the unknown gas. Then oxygen will be 5.06 times less than that.