Question

Why certain compounds are called hydrocarbons? Write the general formula for homologous series of alkanes, alkenes and alkynes and also draw the structure of the first member of each series . Write the name of the reaction that converts alkenes into

alkanes and also write a chemical equation to show the necessary conditions for the reaction to occur

Answer 1

Certain compounds which contain only Hydrogen (H) and Carbon (C) are known as hydrocarbons.
General formula for
Alkanes: CnH2n+2
Alkenes: CnH2n
Alkynes: CnH2n-2
The reaction that converts alkenes into Alkanes is addition(hydrogenation)reaction.
Conditions for conversion of Alkenes to Alkanes, catalyst is Nickel and temperature is 300°C. I've given an example of Ethene to Ethane in photo.
Note: Hydrogenation is a type of addition reaction.

Answer 2

compound are called hydrocarbons because they contain hydrogen and carbon atom.

CnH2n+2=alkanes. c-c-c

cnH2n=alkene. c=c

cnH2n-2= Alkyne. c 3- c

(triple dash)

Addition reaction converts Alkene into alkyne