1. Methane is a saturated hydrocarbon (C – C) while acetylene is an unsaturated hydrocarbon (C ≡ C).
2. Methane being a saturated hydrocarbon does not decolourise Br2 in CCl4 while acetylene being an unsaturated hydrocarbon decolourises Br2 in CCl4.
3. Methane does not decolourise alkaline solution of KMnO4 (Baeyer’s reagent) but acetylene does.
4. Acetylene being a terminal alkyne gives a white ppt. of silver acetylide with ammoniacal silver nitrate solution (Tollen’s reagent) and a red ppt. of copper acetylide with an ammoniacal solution of cuprous chloride. But methane does not undergo these reactions.
