CnH2n-2 + 2Br₂ => CnH2n-2Br4 m tetrabr. =36 g v alchina=2.24l=> n alchina= 0.1mol deci 1 mol alchina....1 mol tetrabr. 0.1 mol achina...0.1 mol tetrabr. 0.1 mol tetrabr=36 g 1 mol tetrabr=360 g M alchina= 360 g - 4 x 80 = 40 g CnH2n-2 = 12n + 2n-2=40 14n-2=40 14n=38 n=2.71 aprox. 3 deci C₃H₄Br₄ verificam: 3 x 12 + 4 x 1 + 4 x 80=360 g/mol