Gọi số mol C2H4, C2H2 là a, b (mol)
=> a + b = \(\dfrac{0,672}{22,4}=0,03\left(mol\right)\) (1)
PTHH: C2H4 + Br2 --> C2H4Br2
a-------------->a
C2H2 + 2Br2 --> C2H2Br4
b----------------->b
=> 188a + 346b = 8,8 (2)
(1)(2) => a = 0,01 (mol); b = 0,02 (mol)
=> \(\left\{{}\begin{matrix}\%V_{C_2H_4}=\dfrac{0,01}{0,03}.100\%=33,33\%\\\%V_{C_2H_2}=\dfrac{0,02}{0,03}.100\%=66,67\%\end{matrix}\right.\)