Question

Un compus organic ce contine C,H si un atom de O se supune arderii folosind 4,03 L O2. Amestecul gazos rezultat contine 2,69 L CO2 si 2,9 g vapori de apa. Care este compusul organic?

Answer 1

Notam formula: CxH2yO
nO2=4,03/22,4=0,18moli
nCO2=2,69/22,4=0,12moli
nH2O=2,9/18=0,16moli
....................(2x+y-1)/2............x.........y
CxH2yO + (2x+y-1)/2 O2 -> xCO2 + yH2O
..........................0,18..............0,12.....0,16
(2x+y-1)/2=0,18x/0,12=1,5x => 2x+y-1-3x=0 => -x+y=1
2x+y-1=2(0,18y/0,16)=2,25y
2x-1,25y=1 => x-0,625y=0,5 (II)
(I)+(II)=> 0,375y=1,5 => y=4
in (I) => -x+4=1 => x=3
formula moleculara: C3H8O => 1 sau 2 propanolul