A balloon contains 0.76 mol n2, 0.18 mol o2, 0.031 mol he and 0.026 mol h2 at 749 mm hg. what is the partial pressure (in mm hg) of o2? give a numeric answer only, no units.
To keep simplicity, let's assume these gases behave ideally so we can use the equations for ideal gas. One of these equation is the Raoult's Law written below.
P* = xP This is another form of the Raoult's Law where x is the mole fraction. Let's find x for O2. x = 0.18/(0.76+0.18+0.031+0.026) = 0.1805