A 200.0 mL flask contains 1.03 mg of O2 and 0.41 mg HE at 288K. Calculate the partial pressure of oxygen and helium in the flask. What is the total pressure?

2 answers

I would convert mg O2 to moles (moles = grams/molar mass) and use PV = nRT to solve for pressure. Do the same for He. Add the partial pressures to find the total P.
@DrBob222
thanks once again for your generous help :)