C:H=12:1.25 =>[tex] \frac{12x}{y}= \frac{12}{1,25} [/tex]
=>15X=12Y
=>X=8;Y=10
f.m.=C8H10
N.E=4 => avem 1 ciclu si 3 legaturi duble
C8H10+[O]+KMnO4(in mediul acid H+)->acidul(nu ne intereseaza)
MKMnO4=158g/mol
MC8H10=106g/mol
=>a g C8H10........53,65gKMnO4
106gC8H10.......158gKMnO4
=>a=36g C8H10