A mixture of O2 and N2 has a total pressure of 2.30 atm. The mixture contains 0.750 moles of N2 and has a volume of 30.0L at 25.0 oC. What is the partial pressure of the O2in atm?

Answer 1

PV = nRT ... Ideal Gas Law

We know the total pressure, the volume and the temperature. We can solve for the number of moles (n).

n = PV/RT

n = (2.30 atm)(30.0 L)/(0.0821 Latm/Kmol)(298K)

n = 2.82 moles

Moles of N2 = 0.750 moles

Moles of O2 = 2.82 - 0.750 = 2.07 moles O2

Partial pressure of O2 = mole fraction of O2 x total pressure

Partial pressure of O2 = (2.07 mol/2.82 mol) x 2.30 atm = 1.69 atm