verificam daca procentele = 100%
=> 69,76 + 11,62 + 18,62 = 100%, verifica
notam compusul CaHbOc
avem 12a g C + b g H + 16c g O
100% compus .......... 69,76% C ........... 11,62% H ........... 18,62% O
86 g compus .......... 12a g C .............. b g H ................... 16c g O
=> a = 5, b = 10, c = 1
=> Fm. = C5H10O1