Pentru simplitate, notam formula: CxH2y si transformam masele in moli, inclusiv volumul de hidrocarbura
n=m/M => nCO2=3,52/44=0,08moli
napa=1,8/18=0,1moli
n=V/Vm=0,448/22,4=0,02moli
1mol...............................xmoli...ymoli
CxH2y + (2x+y)/2O2 -> xCO2 + yH2O
0,02moli.......................0,08moli.0,1moli
x=0,08/0,02=4 si y=0,1/0,02=5
f.m: C4H10