`n_{\text{hh khí}}=\frac{6,72}{22,4}=0,3(mol)`
`m_{\text{ tăng}}=m_{C_2H_4 }=2,8g`
`=> n_{C_2H_4}=\frac{2,8}{28}=0,1(mol)`
`=> n_{CH_4}=0,3-0,1=0,2(mol)`
`a)` Phương trình:
`CH_2=CH_2+Br_2\to CH_2Br-CH_2Br`
`b)` `%V_{CH_4}=\frac{0,2.100%}{0,3}\approx 66,7%`
`%V_{C_2H_4}=\frac{0,1.100%}{0,3}\approx 33,33%`
`%m_{CH_4}=\frac{16.0,2.100%}{2,8+16.0,2}\approx 53,33%`
`%m_{C_2H_4}=\frac{2,8.100%}{2,8+16.0,2}\approx 46,7%`