Question

We have 11.2 l O₂ available, how many grams of oxygen correspond to this volume under standard conditions? Ar(O) = 16

Answer 1

one mole of oxygen correspond to 22.4l at STP

what about 11.2l?

number of moles of $O_2=11.2/22.4=0.5$

mass of oxygen $=0.5(16\times 2)=16g$