100g.......................54.24g O
118g........................x=64g O ==> inseamna ca sunt 4 atomi de O in molecula acidului..
CnH2n-2O4=14n+62
%O=mO/M*100==>54.24=64/14n+62*100==>54.24(14n+62)=6400==>759.36n+3362.88=6400==>759.36n=3037.12==>n=4
HOOC-CH2-CH2-COOH : acid butandioic