posted by Tasha .
A 40.4 g sample of a gas with the empirical formula C5H12 occupied a volume of 3070 mL with a pressure of 5016.0 torr at 168 °C. Enter the molecular formula of the compound.
i calculated n from pv=nrt
but, when i divided it into 40.4 g of c5h12, i got the molar mass of the compound with is around 72.
after that, i had no idea what to do
You're there. The molar mass is 72 and C5H12 has a molar mass of 72 so the molecular formula is C5H12 and not a multiple of C5H12.