1. No simple chemical test to distinguish the two alkynes.
2. But -1- ene decolorizes bromine water, while n- butane does not react with bromine water.
But -1-ene reacts with acidified KmnO4 solution changing it from purple to colourless solution, n- butane does not but-1-ene react with alkaline KMnO4 solution changing it from purple to green solution, n- butane does not.