Đáp án:
\(\begin{array}{l}
\% {m_{{C_2}{H_6}}} = 26,79\% \\
\% {m_{{C_2}{H_4}}} = 50\% \\
\% {m_{{C_2}{H_2}}} = 23,21\%
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
{C_2}{H_4} + B{r_2} \to {C_2}{H_4}B{r_2}\\
{C_2}{H_2} + 2B{r_2} \to {C_2}{H_2}B{r_4}\\
{V_{{C_2}{H_6}}} = V \text{ thoát ra } = 1,12l\\
{n_{{C_2}{H_6}}} = \dfrac{{1,12}}{{22,4}} = 0,05\,mol\\
{m_{{C_2}{H_6}}} = 0,05 \times 30 = 1,5g\\
{n_{B{r_2}}} \text{ phản ứng } = 1 \times 0,4 \times \frac{1}{2} = 0,2\,mol\\
hh:{C_2}{H_4}(a\,mol),{C_2}{H_2}(b\,mol)\\
\left\{ \begin{array}{l}
28a + 26b = 5,6 - 1,5\\
a + 2b = 0,2
\end{array} \right.\\
\Rightarrow a = 0,1;b = 0,05\\
\% {m_{{C_2}{H_6}}} = \dfrac{{1,5}}{{5,6}} \times 100\% = 26,79\% \\
\% {m_{{C_2}{H_4}}} = \dfrac{{0,1 \times 28}}{{5,6}} \times 100\% = 50\% \\
\% {m_{{C_2}{H_2}}} = 100 - 50 - 26,79 = 23,21\%
\end{array}\)
