ro=ms/Vs => ms=ro*Vs=0,8*500=400g solutie
86=md*100/400=>86=md/4 => md=86*4=344g alcool etilic
alcoolul etilic este un alcool cu 2 at de C, si cu urmatoarea structura: CH3CH2OH, mai simplu C2H6O; MC2H6O=2*12+6+16=46g/mol
344g........x=?
C2H6O + 3O2 -> 2CO2 + 3H2O
46g.....3*22,4L
x=344*3*22,4/46=502,539318L O2
502,53L........21%
y..................100%
y=502,539318*100/21=2393L aer