\(a,n_{C_2H_4}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ n_{C_2H_4Br_2}=\dfrac{37}{188}=0,197\left(mol\right)\)
PTHH: \(CH_2=CH_2+Br-Br\rightarrow CH_2Br-CH_2Br\)
0,2-------------->0,2--------->0,2
\(\rightarrow m_{Br_2}=0,2.160=32\left(g\right)\\ b,\rightarrow H=\dfrac{0,197}{0,2}.100\%=98,5\%\)