Question: what happens when ethylene is passed through cold dilute alkaline potassium permanganate?
Answer: What happens when ethylene gas is passed through a solution of alkaline KMnO4 solution? ... Ethyne on reacting with cold KMnO4 adds 4OH- to the triple bond. Forming a very unstable compound (OH)2CH--CH(OH)2. 2 OH- on a single carbon are unstable and the molecule would lose 2H2O and form Ethan-1,2-dial.