-m=2,2g si M=44g/mol---.> niu sau n= 2,2g/44g/mol=0,05mol
-deci, in reactia de ardere intra 0,05mol CxHy
-CaHb prin ardere---> aCO2 +b/2H2o ori 0,05mol
M=44g/molCO2 SI M= 18g/mol H20------>
0,05xax44= 6,6----->a=3moliC
0,05xb/2x18=3,6----> b=8moliH
HIDROCARBURA ARE FORMULA MOLECULARA C3H8----PROPAN
-CH3-CH2-CH3 +5 O2= 3CO2+4H2O
- IN 44g .......36gC.........8gH
in 100g .....x..............y ---------> calculeaza x-%C si y-%H