\(a,n_{Br_2}=\dfrac{32}{160}=0,2\left(mol\right)\\ PTHH:C_2H_4+Br_2\rightarrow C_2H_4Br_2\\ Theo.pt:n_{C_2H_4}=n_{Br_2}=0,2\left(mol\right)\\ n_{hhkhi}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\\ n_{CO_2}=0,3-0,2=0,1\left(mol\right)\\ m_{C_2H_4}=0,2.28=5,6\left(g\right)\\ m_{CO_2}=0,1.44=4,4\left(g\right)\\ b,C_{MddBr_2}=\dfrac{0,2}{0,5}=0,4M\)