A mixture of methane, ethylene and acetylene gases is passed through a Wolfs bottle containing ammoniacal cuprous chloride. The gas coming out is

Aeetylene reacts with ammonical cuprous chloride to form red ppt. of copper acetylide while methane and ethylene do not react (since they do not have acidic hydrogen). They come out from the bottle

$\mathrm{CH}\equiv \mathrm{CH}+2\left[\mathrm{Cu}{\left({\mathrm{NH}}_3\right)}_2\right]\mathrm{OH}\to \mathrm{Cu}-\mathrm{C}\equiv \mathrm{C}-\mathrm{Cu}+4{\mathrm{NH}}_3+2{\mathrm{H}}_2\mathrm{O}$

$$\begin{gathered} {\mathrm{CH}}_4+\text{ Ammonical }{\mathrm{Cu}}_2{\mathrm{Cl}}_2\to \text{ No reaction } \\ {\mathrm{C}}_2{\mathrm{H}}_4+\text{ Ammonical }{\mathrm{Cu}}_2{\mathrm{Cl}}_2\to \text{ No reaction } \end{gathered}$$