Ethylene reacts with bromine: C2H4 + Br2

Chemical Reaction Demonstration: Ethylene Production and Bromine Reaction
🧪 The experiment involves reacting ethanol (rượu etylic) with concentrated sulfuric acid (axit sufuric đặc) by heating in a flask connected to a scrubbing bottle containing dilute sodium hydroxide (natri hydroxit loãng) solution.
💨 The gas mixture produced, containing ethylene (etylen), passes through the scrubbing bottle and is then directed into a test tube containing bromine (Brom) solution.
🔬 The primary observable phenomenon is the decolorization of the bromine solution, indicating the reaction of ethylene gas.
✍️ The reaction between ethylene ($C_2H_4$) and bromine ($Br_2$) follows the addition reaction equation: $C_2H_4 + Br_2 \rightarrow C_2H_4Br_2$ (1,2-dibromoethane).

Key Points & Insights
➡️ The decolorization of the bromine solution confirms the formation and presence of ethylene gas ($C_2H_4$).
➡️ The reaction sequence demonstrates the dehydration of ethanol catalyzed by concentrated sulfuric acid at high temperatures to produce alkenes.
➡️ Ethylene undergoes an addition reaction with bromine water, consuming the bromine and causing the characteristic brown color to disappear.

📸 Video summarized with SummaryTube.com on Jan 20, 2026, 14:44 UTC