Question

What mass of oxygen gas is present in a `6.25*L` volume of this gas under a pressure of `100*kPa`, and a temperature of `298*K`?

Answer 1

`"Mass of dioxygen gas"~=8*g`

Explanation:

We solve for `"mass"` using the old Ideal Gas equation...

`"mass"=(PV)/(RT)xx"molar mass of the gas"`

`=(6.25*Lxx100*kPaxx32.00*g*mol^-1)/(8.314*L *kPa *K^-1 *mol^-1xx298*K)`

`=??*g`

With these problems, you simply just have to know that most of the elemental gases (all of them save the Noble Gases) are bimolecular.