Question

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

A. methane

B. acetylene

C. mixture of methane and ethylene

D. original mixture

Answer 1

The correct option is (c) mixture of methane and ethylene.

Wolf bottle contains ammoniacal cuprous chloride reacts only with alkyne containing terminal triple bond to form trans alkene. Thus the gases which will come out of the bottle will be methane and ethylene only.

Acetylene 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

CH≡CH+2[Cu(NH₃​)_2​]OH→Cu−C≡C−Cu+4NH₃​+2H₂​O

CH₄​+ Ammonical Cu₂​Cl₂​→ No reaction

C₂​H₄​+ Ammonical Cu₂​Cl₂​→ No reaction