1)

\(\begin{array}{l}
a)\\
{C_2}{H_4} + B{r_2} \to {C_2}{H_4}B{r_2}\\
nC{H_4} = \frac{{3,36}}{{22,4}} = 0,15\,mol\\
nhh = \frac{{5,6}}{{22,4}} = 0,25\,mol\\
 =  > n{C_2}{H_4} = 0,25 - 0,15 = 0,1mol\\
 =  > nB{r_2} = 0,1\,mol\\
CMB{r_2} = \frac{{0,1}}{{0,2}} = 0,5M\\
b)\\
\% V{C_2}{H_4} = \frac{{0,1 \times 22,4}}{{5,6}} \times 100\%  = 40\% \\
\% VC{H_4} = 100 - 40 = 60\% 
\end{array}\)

2)

\(\begin{array}{l}
C{H_4} + 2{O_2} \to C{O_2} + 2{H_2}O\\
{C_2}{H_4} + 3{O_2} \to 2C{O_2} + 2{H_2}O\\
a)\\
hh:C{H_4}(a\,l),{C_2}{H_4}(b\,l)\\
a + b = 22,4\\
a + 2b = 35,84\\
 =  > a = 8,96;b = 13,44\\
\% VC{H_4} = \frac{{8,96}}{{22,4}} \times 100\%  = 40\% \\
\% V{C_2}{H_4} = 100 - 40 = 60\% \\
b)\\
V{O_2} = 8,96 \times 2 + 13,44 \times 3 = 58,24l\\
Vkk = 58,24 \times 5 = 291,2l
\end{array}\)