M sapun...............100%
32g O.................12,11%
M sapun=32*100/12,11=264g/mol
avem 2 posibilitati: poate fi sapun saturat sau nesaturat
luam intai primul caz
formula generala: CnH2n+1COOK sau Cn+1H2n+1KO2
Msapun=12(n+1)+2n+1+39+16*2=12n+12+2n+1+39+32=14n+84=264 => 14n=180 => n=12,85 nu e intreg
daca e nesaturat are formula Cn+1H2n-1KO2
Msapun=14n+82=264 => 14n=182 => n=13
un sapun nesaturat de potasiu cu 14 atomi de C
