d(oxigen) = M.comp/M.O2
=> M.comp. = d(O2) x M.O2 = 2,89x32 = 92,5 g/mol
100% - 51,89% C - 38,38% Cl = 9,73% H
notam compusul halogenat CaHbClc
100% .......... 51,89% C .............. 9,73% H ........... 38,38% Cl
92,5 g ........ 12a g C ................ b g H .................. 35,5c g Cl
=> a = 4 , b = 9 , c = 1
=> compusul halogenat = C4H9Cl