Hydrocarbons

Organic compound, any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen. The few carbon-containing compounds not classified as organic include carbides, carbonates, bicarbonate and cyanides.

Hydrocarbon:  The compounds formed by the combination of carbon and hydrogen are called hydrocarbon. The major source of hydrocarbon compound is mineral oil. Hydrocarbons are classified to two main categories according the bond between carbon and carbon atom.

1.Saturated hydrocarbons: if there is only one bond between carbon and carbon atom then such type of compounds are called saturated hydrocarbons. The meaning of saturated means nothing can be added further there. They are so stable in nature and hence are also called paraffins. They are also called alkanes. There general formula is C_nH_2n+2. Examples are methane, ethane, propane, butane etc.

2. Unsaturated hydrocarbon: If there is more than one covalent bond between carbon and carbon atom in hydrocarbon then they are called unsaturated hydrocarbon. It means some element can be added there. They are unstable in nature.  Unsaturated hydrocarbons are further classified into two types, alkene and alkyne.

Alkene: If there is double bond between carbon and carbon atom, such hydrocarbons are called alkenes. They are also called olefines and their general formula is C_nH_2n, where value of n starts from 2.

Alkynes are the hydrocarbon compounds having at least one triple bond between carbon carbon atom. They are also called acetylenes. They are represented by general formula C_nH_2n-2 where value of n starts from 2.

Homologous series: the group of hydrocarbon compound which can be expressed by single formula is called homologous series. For example, methane, ethane, and propane are part of a homologous series. The only difference among these molecules is that they have different numbers of CH₂ groups. Each member of a homologous series is called a homologue, which can also be spelled ''homolog.'' For example, methane and ethane are homologues and belong to the same homologous series. They differ from each other by one CH₂ group. The formula of methane is CH₄ and the formula of ethane is C₂ H₆.

Alkyl radical: The group of atoms(or radical) formed by removing one hydrogen from alkane is called alkyl radical. For example removing one hydrogen from methane(CH₄) creates CH₃⁺ radical and so on.

CH₄ - H → CH₃⁺

C₂H₆ - H → C₂H₅⁺

Functional group is a group of atoms responsible for the characteristic behavior of the class of compounds in which the group occurs, as the hydroxyl group in alcohols, oxygen in ether etc.