See image — Hydrocarbons Chemistry Question

💡 Solution & Explanation

Concept: Alkaline solution of copper (I) chloride (ammoniacal cuprous chloride, Cu2Cl2 in NH3) is a selective reagent that reacts with terminal alkynes (acetylides) to form a red/brick-red precipitate of copper acetylide. It does not react with alkenes or alkanes under these conditions. Step 1: Identify each component and its reactivity with ammoniacal CuCl. - C2H6 (ethane): saturated alkane, no reaction with ammoniacal CuCl. Passes through. - C2H4 (ethylene): alkene, no terminal alkyne C-H bond, no reaction with ammoniacal CuCl. Passes through. - C2H2 (acetylene): terminal alkyne, reacts with ammoniacal CuCl to form copper(I) acetylide (Cu2C2), a red precipitate. Gets absorbed/retained in the Woulf's bottle. Step 2: Determine what comes out. Since C2H2 is absorbed by the reagent (forms precipitate), only C2H6 and C2H4 pass through and come out as the exiting gas mixture. Step 3: Evaluate options. (a) Original mixture - incorrect, C2H2 is removed. (b) C2H6 only - incorrect, C2H4 also passes through. (c) C2H6 and C2H4 mixture - correct, both alkane and alkene are unreactive toward ammoniacal CuCl and come out together. (d) C2H4 and C2H2 - incorrect, C2H2 is retained and C2H6 should also come out. Therefore, the correct answer is C.