\(m_T=8,8\left(g\right)=m_S\\ \Rightarrow n_S=0,4\left(mol\right)\\ \Rightarrow n_{H_2\left(S\right)}=n_S-n_{HDCB}=0,1\left(mol\right)\\ \Rightarrow n_{H_2\left(pứ\right)}=0,2\left(mol\right)\)
BT liên kết π \(\Rightarrow n_{Br_2}=2n_{C_2H_2}+n_{C_2H_4}-n_{H_2\left(pứ\right)}=0,2\left(mol\right)\)