Question

What is the functional group of alkane and alkene?

Answer 1

Hint :Alkanes are the saturated hydrocarbon whereas alkenes are the unsaturated hydrocarbon. Functional groups are a specific group of atoms present in a compound which is responsible for the characteristic chemical reaction of that particular compound.

Complete Step By Step Answer:
A hydrocarbon is a class of an organic compound which is composed only of the elements hydrogen and carbon atoms. Alkanes are organic compounds that consist of hydrocarbons in which the carbon-to-carbon, carbon –to- hydrogen are bonded with a single bond. Sometimes, it is also described as paraffin. They are also called saturated hydrocarbons. Alkanes have the general formula $ {C_n}{H_{2n + 2}} $
Example- Methane, Ethane etc.
 

Whereas, alkenes are a class of organic compounds that consist of hydrocarbons, but in this type of hydrocarbon the carbon-to-hydrogen are linked with a single bond and they have carbon-to-carbon linked with a double bond. They are also called unsaturated hydrocarbons. Sometimes, it is also described as olefins. Alkenes have the general formula $ {C_n}{H_{2n}} $ .
Example – Ethene, Propene etc.

Functional group is a specific group of atoms which is present within a compound that is responsible for the characteristic chemical reactions of that compound. These types of groups exhibit a characteristic reactivity and display distinctive chemical behavior.
In the given question,
The carbon-to-carbon single bond $ (C - C) $ is considered as the functional group of alkane
Similarly, the carbon-to-carbon double bond $ (C = C) $ is considered a functional group of alkene.

Note :
It should be remembered that alkanes are not able to decolorize the red- brown colour of bromine water $ (B{r_2}) $ whereas alkenes are able to decolorize it. So, bromine water test is a test used to determine the unsaturation.