Question

Give a chemical test to distinguish between saturated and unsaturated hydrocarbons.

Answer 1

Hint: Saturated hydrocarbons are those in which all the bonds are single bond and unsaturated hydrocarbons are those in which either double bond or triple bond is present. One of the best tests that can be used for distinguishing them is the bromine water test.

Complete Solution :
- There are two types of hydrocarbons in the organic compounds, these are saturated hydrocarbons and unsaturated hydrocarbons. Saturated hydrocarbons are those in which all the bonds are single bonds and unsaturated hydrocarbons are those in which either double bond or triple bond is present.
- Methane, ethane, propane, butane, etc are examples of saturated hydrocarbons because all the bonds are single. Ethene, propene, butyne, hexyne, etc are the example of unsaturated hydrocarbons because they have either double or triple bonds.
- One of the best tests that can be used for distinguishing them is the bromine water test. In this test, bromine is used as bromine water and the solution of bromine and water is known as bromine water. The color of the bromine solution is red-brown because of the presence of bromine.
- Now, when this bromine water is treated with an unsaturated hydrocarbon, the color of the solution will change from red-brown to colorless. But when this bromine solution is treated with saturated hydrocarbon, the color of the solution remains the same.
So, we can say that unsaturated hydrocarbon can decolorize the bromine water whereas saturated hydrocarbon cannot.

Note: Another test that can be used to distinguish between the saturated and unsaturated hydrocarbon is Bayer's reagent. The unsaturated hydrocarbon will change the color of Bayer's reagent but the saturated hydrocarbon will not.