\(a)\\ C_2H_4 + Br_2 \to C_2H_4Br_2\\ n_{C_2H_4} = n_{Br_2} = \dfrac{80.10\%}{160} = 0,05(mol)\\ \Rightarrow \%m_{C_2H_4} = \dfrac{0,05.28}{2}.100\% = 70\%\\ \%m_{CH_4} = 100\% - 70\% = 30\%\)
\(b)\) Sản phẩm : Đibrom etan
\(n_{C_2H_4Br_2} = n_{Br_2} = 0,05(mol)\\ \Rightarrow m_{C_2H_4Br_2} = 0,05.188 = 9,4\ gam\)