Đáp án:
a) C2H4: 16,8 g; CH4: 4,8 g
b) 1M
Giải thích các bước giải:
a)
$\begin{gathered}
{n_{hh}} = \dfrac{{20,16}}{{22,4}} = 0,9mol;{n_{B{r_2}}} = 0,3.2 = 0,6mol \hfill \\
{C_2}{H_4} + B{r_2} \to {C_2}{H_4}B{r_2} \hfill \\
\Rightarrow {n_{{C_2}{H_4}}} = {n_{B{r_2}}} = 0,6mol \hfill \\
\Rightarrow {n_{C{H_4}}} = 0,9 - 0,6 = 0,3mol \hfill \\
\Rightarrow {m_{{C_2}{H_4}}} = 0,6.28 = 16,8\left( g \right);{m_{C{H_4}}} = 0,3.16 = 4,8\left( g \right) \hfill \\
\end{gathered} $
b)
$\begin{gathered}
{n_{{C_2}{H_2}}} = \dfrac{{8,96}}{{22,4}} = 0,4mol \hfill \\
{C_2}{H_2} + 2B{r_2} \to {C_2}{H_4}B{r_4} \hfill \\
\dfrac{{{n_{{C_2}{H_2}}}}}{1} = 0,4 > \dfrac{{{n_{B{r_2}}}}}{2} = 0,3 \hfill \\
\end{gathered} $
⇒ ${C_2}{H_2}$ dư, $B{r_2}$ hết
${n_{{C_2}{H_2}B{r_4}}} = \dfrac{1}{2}{n_{B{r_2}}} = 0,3mol \Rightarrow {C_{Mdd}} = \dfrac{{0,3}}{{0,3}} = 1M$
