\(CTC:C_nH_{2n}\)
\(n_{Br2}=5.10^{-3}\left(mol\right)\)
\(PTHH:C_nH_{2n}+Br_2\rightarrow C_nH_{2n}Br_2\)
_______5.10-3____5.10-3_____________
\(\Rightarrow M_{CnH2n-2}=\frac{0,21}{5.10^{-3}}=42\)
\(\Leftrightarrow14n=42\Rightarrow n=3\left(C_3H_6\right)\)
\(C=C-C:propilen\)