Question

Compusul A are compozitia exprimata prin raportul de masa C:H:O=18:3:16. Pentru arderea a 2 moli de compus A se consuma 156,8 l oxigen.
Compusul A este: glicerina, C3H602,CH3-CH2-OH, C6H12O4, acidul propionic.

Answer 1

Teorie:
Consideram substanta de tipul CxHyOz
Din raportul masic, determini compozitia x:y:z
Calcule:
mC/mH=18/3=6/1=>12x/y=6/1=>6y=12x=>y=2x
mC/mO=18/16=9/8=>12x/16z=9/8=>9*16z=12*8x=>9z=6x=>z=2x/3
mH/mO=3/16=>y/16z=3/16=>3*16z=16y=>y=3z
=>formula substantei:C(x)H(2x)O(2x/3)
Reactia de ardere: CxH2xO2x/3 + 7x/6 O2 = x CO2 + x H2O
1 mol compus se consuma a*22,4 l oxigen
2 moli compus se consuma 156.8 l oxigen
a*44.8=156,8=>a=3,5 moli oxigen
7x/6=3,5=>7x=21=>x=3=>C3H6O2
Raspuns:
Compusul A este C3H6O2