Question

What are hydrocarbons? Write the general formula of (i) saturated hydrocarbons, and (ii) unsaturated hydrocarbons and draw the structure of one hydrocarbon of each type. How can an unsaturated hydrocarbon be made saturated?

Answer 1

The compounds entirely consisting of carbons and hydrogens are known as Hydrocarbons. There are different categories in which hydrocarbons are divided out of which the two are:

(i) Saturated Hydrocarbons: The compounds of carbon having only single bonds between the carbon atoms are called saturated compounds. This includes alkanes, having a general formula C_nH_2n+2.

(ii) Unsaturated Hydrocarbons: The compounds of carbon having double and triple bonds between the carbon atoms are called unsaturated compounds. This includes alkenes and alkynes having general formula C_nH_2n  and C_nH_2n-2, respectively.

Example
(i) Saturated hydrocarbon: C₂H₆ (Ethane)
    Structure:

(ii) (a) Unsaturated hydrocarbon: C₂H₄ (Ethene)
Structure:

(b) Unsaturated hydrocarbon: C₂H₂ (Ethyne)
Structure: