Question #777e2

1 Answer
May 12, 2016

The pressure is unknown. The partial pressure is a multiple of the mole fraction of each component.

Explanation:

We have volume, and amount of substance; we do not have temperature, which we require if pressure is to be calculated. I assume that the temperature is 298K.

Moles of helium: 32.6g4.0gmol1=8mol

Moles of dioxygen: 51.2g32.0gmol1=1.6mol

The total pressure P=nRTV =

(8.0+1.6)mol×0.0821LatmK1mol1×298K0.150L = PT

The partial pressure of dioxygen PO2=PO2PT = 1.6mol(8+1.6)mol×PT.

This sounds like a deep sea diving mix, where helium replaces dinitrogen in order to avoid the narcotic effect of dinitrogen.