Gọi x và y lần lượt là số mol C₂H₄ và C₂H₂ trong hỗn hợp ban đầu.

Khi dẫn hỗn hợp X qua dung dịch brom dư, cả hai khí đều tham gia phản ứng:

$$\begin{gathered} {\text{C}}_2{\text{H}}_4+{\text{Br}}_2\to {\text{C}}_2{\text{H}}_4{\text{Br}}_2 \\ {\text{C}}_2{\text{H}}_2+2{\text{Br}}_2\to {\text{C}}_2{\text{H}}_2{\text{Br}}_4 \end{gathered}$$

Khối lượng bình brom tăng $={\text{m}}_{{\text{C}}_2{\text{H}}_4}+{\text{m}}_{{\text{C}}_2{\text{H}}_2}=28\text{x}+26\text{y}=1,34\left(1\right)$

Khi cho X qua dung dịch AgNO₃/NH₃ có phản ứng:

$\begin{array}{l}\text{HC}\equiv \text{CH}+2{\text{AgNO}}_3+2{\text{NH}}_3\to \text{AgC}\equiv \text{CAg}\downarrow +2{\text{NH}}_4{\text{NO}}_3\\ \text{ \hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}y\hspace{0.17em}mol\hspace{1em} \hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}y\hspace{0.17em}mol}\end{array}$

Khối lượng kết tủa: ${\text{m}}_{{\text{Ag}}_2{\text{C}}_2}=240\text{y}=7,2\to \text{y}=0,03 \text{mol}\stackrel{\left(1\right)}{\to }\text{x}=0,02 \text{mol}$

$\% {\text{V}}_{{\text{C}}_2{\text{H}}_2}=\frac{0,03}{0,02+0,03}.100\%=60\%\text{.}$