A mixture of n2 and o2 contains 2.7 grams of O2 and occupies 3.1 L at 28 degrees Celsius, 810 mmHg. how many grams of N2 are present?

Answer 1

Use PV = nRT to calculate partial pressure of O2.
partial pressure O2 + partial pressure N2 = Ptotal = 810 mm Hg. Solve for partial pressure N2.
Use PV = nRT to solve for n = number of moles N2, then convert to grams.

Answer 2

what are the partial pressures of N2 and O2 in air at .8atm? this is the only info avaiable