nhh = 5.6/22.4 = 0.25 (mol)
nBr2 = 0.5*0.2 = 0.1 (mol)
C2H4 + Br2 => C2H4Br2
0.1_____0.1
nCH4 = 0.25 - 0.1 = 0.15 (mol)
VC2H4 = 0.1*22.4 = 2.24 (l)
VCH4 = 0.15*22.4 = 3.36 (l)
mCH4 = 0.15*16 = 2.4 (g)
mC2H4 = 0.1*28 = 2.8 (g)
%mCH4 = 2.4/(2.4 + 2.8) * 100% = 46.15%
%mC2H4 = 100 - 46.15 = 53.85%
Chúc bạn học tốt !!!