a)
nC2H2=16,8/22,4=0,75 mol
nBr2=0,8x1=0,8 mol
\[\begin{array}{l}
{C_2}{H_2} + B{r_2} \to {C_2}{H_2}B{r_2}\\
{C_2}{H_2}B{r_2} + B{r_2} \to {C_2}{H_2}B{r_4}
\end{array}\]
nC2H2Br2=0,75-0,05=0,7 mol
nC2H2Br4=0,05 mol
b)
\[\begin{array}{l}
Ca + 2{H_2}O \to Ca{(OH)_2} + {H_2}\\
Ca{C_2} + 2{H_2}O \to {C_2}{H_2} + Ca{(OH)_2}\\
{C_2}{H_2} + {H_2} \to {C_2}{H_4}\\
{C_2}{H_2} + 2{H_2} \to {C_2}{H_6}\\
{C_2}{H_2} + 2B{r_2} \to {C_2}{H_2}B{r_4}\\
{C_2}{H_4} + B{r_2} \to {C_2}{H_4}B{r_2}
\end{array}\]
A gồm H2 và C2H2
B gồm C2H2,C2H4 và C2H6
D gồm C2H6