How would you test whether a substance is an alkane or an alkene?

In order to determine if there is unsaturation (the presence of a double bond), the bromine will react with the double bond and cause the dark brown color to disperse.

Additionally, a double bond will react with Baeyer's reagent, changing the color to brown.

Perform the bromine water test. Alkenes will decolorize bromine water, while alkanes will not show any change.

To test whether a substance is an alkane or an alkene, you can perform a simple chemical test called the bromine water test.

1. Add a small amount of bromine water (a solution of bromine in water) to the substance.
2. Observe the color change:
   • If the substance is an alkane, there will be no observable change in color.
   • If the substance is an alkene, the orange-brown color of the bromine water will fade as the bromine reacts with the alkene, turning colorless.

This test works because alkenes readily undergo addition reactions with bromine, while alkanes do not.