Partial pressure is found by Dalton's Law: Px = PTotal ( nx / nTotal ) where Px = partial pressure of gas x PTotal = total pressure of all gases nx = number of moles of gas x nTotal = number of moles of all gases
Step 1 Find PTotal Standard pressure is 1 atm.
Step 2 Add up the number of moles of the component gases to find nTotal nTotal = noxygen + nnitrogen nTotal = 100 + 900 nTotal =1000cm3
Step 3 Now you have all the information needed to plug the values into the equation and solve for Poxygen P-oxygen = PTotal ( n-oxygen / nTotal ) oxygen = 1 atm ( 100 / 1000 ) oxygen= 0.1atm