(a) What are hydrocarbons ? Give examples.
(b) Give the structural differences between saturated and unsaturated hydrocarbons with two examples each.
(c ) What is functional group ? Examples of four different functional groups.

Explanation

(a) Compounds of carbon and hydrogen are called hydrocarbons. For example, methane, ethane, etc.
(b) Saturated hydrocarbons contain carbon-carbon single bonds.
Unsaturated hydrocarbons contain at least one carbon-carbon double or triple bond.
`underset("Saturated hydrocarbons")(underset("Methane")(H-underset(H)underset(|)overset(H)overset(|)C-H)" "underset("Ethane")(H-underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-H))" "underset("Unsaturated hydrocarbons")(underset("Ethene")({:(H),(" \"),(" /"),(H):}C=C{:(" H"),("/"),("\"),(" H"):})" " underset("Ethyne")(H-C-=C-H))`
(c ) An atom/group of atoms joined in a specific manner which is responsible for the characteristic chemical properties of the organic compounds is called a functional group. Examples are hydroxyl gropo (-OH), aldehyde group (-CHO), ketonic group `(underset("/")overset("\")(" "C)=O)`, carboxylic group (-COOH), etc.