nX=4,48/22,4=0,2 mol
M tb X=15,25.2=30,5
Theo quy tắc đg chéo, nC2H2/nC3H8=(30,5-26)-(44-30,5)=1/3
nC2H2=x mol => nC3H8=3x mol
=> x+3x=0,2 => x=0,05
=> nC2H2=0,05 mol
nC3H8=0,15 mol
C2H2+5/2O2=2CO2+H2O
C3H8+5O2=3CO2+4H2O
=> nO2=0,05.5/2+0,15.5=0,875 mol
=> V O2(min)=0,875.22,4=19,6l