Carbon Compounds

Introduction :

Carbon compounds play an important role in our daily life. Every living organism possess hydrocarbons. We cannot think of living life without carbon compounds. Carbon compounds with single bond between two carbon atoms are called alkanes and with triple bond are called alkynes e.g. ethane, ethene and ethyne. Apart from carbon and hydrogen, hydrocarbons also contain other elements, namely oxygen, nitrogen and sulphur etc.
The basic carbon compounds are - alkanes, alkenes and alkynes. Let us describe each of them:

Alkanes - Alkanes are also known as saturated hydrocarbons. In alkanes, the hydrogen and the carbon atoms are joined using the single bond. The simplest alkane is CH₄ or methane, which is as shown below. Examples of larger alkanes are waxes and saturated oils.

Alkanes are acyclic molecules. It is saturated. They are not very reactive.
Alkenes - An alkene is an unsaturated carbon compound. It contains atleast one carbon-carbon double bond. The general formula for alkenes is C_nH_2n. Example of the simplest alkene is Ethylene (C₂H₄).

Alkynes - These hydrocarbons have a triple bond between two carbon atoms. The general formula for alkynes is C_nH_2n-2. Alkynes seem to be more reactive, but are hydrophobic. They are also known as acetylenes.
Group of atoms in a structure that determines the characteristic reactions of a compound is called functional group. Few important functional groups are:
a) Alcohol
b) Aldehyde
c) Ketone
d) Carboxyl
e) Ester
Let us learn the naming of some of the carbon compounds:

Naming of Alcohols:

Alcohols are hydroxy derivatives of alkanes. When one hydrogen atom of alkane is replaced by a -OH group then formation of alcohol takes place. Alcohols are also called as alkanols. Alcohols have general formula C_nH_2n+1OH.
Alcohols are homologous series of compounds that contain - OH functional group. While naming alcohol letter 'e' from homologous series of alkane is replaced by 'ol' as shown:
Alkane                                                                                    Alcohol
Methane                                                                                 Methanol
Ethane                                                                                    Ethanol
Propane                                                                                  Propanol
When more than two carbon atoms are present in a carbon compound then while writing the name of a compound the position of carbon atoms is also specified.
E.g. CH₃ - CH₂ - CH₂OH      Propan -1 -ol

Naming of Carbonyl Compounds:

Aldehydes and ketones represent a family of organic compounds known as carbonyl compounds.

Naming of Aldehydes:
While naming aldehydes the letter 'e' of corresponding homologous series os alkane is replaced by 'al' as shown:

Alkane                                                                           Aldehyde
Methane                                                                        Methanal
Ethane                                                                           Ethanal
Propane                                                                         Propanal

Naming of Ketones:
While naming ketones, the letter 'e' of corresponding homologous series of alkane is replaced by 'one'.
E.g. The simplest ketone is acetone and IUPAC name is propan-2-one.
Few more members of ketone series are: Butan - 2 -one, Pentan - 3 - one etc.

Naming of Carboxylic Acid:

Carboxylic acids are homologous series of compounds having -COOH group. While naming carboxylic acids the letter 'e' of corresponding homologous series of alkanes is replaced by 'oic' as shown:
Alkane                                                                                            Carboxylic Acid
Methane                                                                                          Methanoic Acid (Formic Acid)
Ethane                                                                                             Ethanoic Acid
Propane                                                                                           Propanoic Acid