Carbon and Its Compounds Nomenclature of hydrocarbons class 10 Science

Carbon and Its Compounds

Hydrocarbons: Nomenclature Part 2

Naming of hydrocarbon with Halo group:

Example: (CH3Cl) The common name of this molecule is methyl chloride. There is one carbon atom in this compound. So its parent name is Methane. Since one chloro group is present in this compound, hence its IUPAC name is chloro-methane. Following is the structural formula of chloro-methane.

structural formula of chloromethane

Example: (C3H7Cl) The common name of this compound is propyl chloride.

IUPAC Name:

Number of carbon atoms = 3
Functional group: Chloro
Thus, IUPAC Name is Chloro-propane.
Following is the structural formula of chloro-pentane.

structural formula of chloropropane

Example: C3H7Br

Common name of this compound is propyl bromide. Its IUPAC name is bromo-propane. Following is the structural formula of bromo-propane:

structural formula of bromopropane

Example: CH3H7I

Common name of this compound is hexyl iodide. Its IUPAC name is iodo-hexane. Following is the structural formula of iodo-hexane:

structural formula of iodohexane

Naming of alcohol group

Example: CH3OH

The common name of this compound is methyl alcohol.

IUPAC Name:

Number of carbon atom: 1
Functional group: Alcohol (suffix : ol)
IUPAC Name: Methane – e Methane – e + ol = Methanol.
Following is the structural formula of methanol.

structural formula of methanol

Example: CH3CH2OH

The common name of this compound is ethyl alcohol.

IUPAC Name:

Number of carbon atoms: 2
Functional group: Alcohol
Hence, IUPAC name is ethanol.
Following is the structural formula of ethanol.

structural formula of ethanol

Example: C6H13OH

The common name of this compound is hexyl alcohol.

IUPAC Name:

Number of carbon atoms: 6
Functional group: Alcohol
Hence, its IUPAC name is hexanol
Following is the structural formula of hexanol.

structural formula of hexanol

Naming of Aldehyde group (−CHO):

IUPAC name of alkane having aldehyde group is written as follows:

The suffix of aldehyde group is “al”.
Alkane – e + al = Alkanal
Methane – e + al = Methanal
Ethane – e + al = Ethanal, and so on.

Example: HCHO

Common name of this compound is formaldehyde.

IUPAC Name:

Number of carbon atom: 1
Hence, IUPAC name is methanal.
Following is the structural formula of methanal.

structural formula of methanal

Example: CH3CHO

Common name of this compound is acetaldehyde.

IUPAC Name:

Number of carbon atoms: 2
Functional group: Aldehyde
Hence, IUPAC name is ethanal.
Following is the structural formula of ethanal.

structural formula of ethanal

Example: C6H13CHO

Number of carbon atoms in this compound is 7 and hence, its IUPAC name is heptanal.

structural formula of heptanal

Naming of Carboxylic Acid (−COOH):

Suffix for carboxylic acid is ‘oic acid”.
Thus an alkane having carboxylic acid is named as:
Methane – e + oic acid = Methanoic acid
Ethane – e + oic acid = Ethanoic acid.

Answer: HCOOH

Common name of this compound is formic acid. It has one carbon atom, hence its IUPAC name is methanoic acid. Following is the structural formula of methanoic acid.

structural formula of methanoic acid

Example: CH3COOH

Common name of this compound is acetic acid. It has two carbon atoms, hence its IUPAC name is ethanoic acid. Structural formula of ethanoic acid is as follows:

structural formula of ethanoic acid

Example: C4H9COOH

It has five carbon atoms, hence its IUPAC name is pentanoic acid. Structural formula of pentanoic acid is as follows:

structural formula of pentanoic acid

Naming of Ketone (−CO−):

Example: CH3−CO−CH3

Common name of this compound is dimethyl ketone. It has three carbon atoms and functional group is ketone, hence its IUPAC name is propanone. Structural formula of propanone is as follows:

structural formula of propanone

Example: C2H5−CO−C2H5

Common name of this compound is dethyl ketone. It has five carbon atoms and functional group is ketone, hence its IUPAC name is pentnone. Following is the structural formula of pentanone:

structural formula of pentanone

Homologous Series:

Series of compounds with same general formula and functional group is known as homologous series. Compounds belonging to the same homologous series show similar properties. Compounds of homologous series differ by CH2 from their consecutive members. Each subsequent compound in a homologous series differs by 14 au. Example: Alkanes; such as, Methane, Ethane, Propane, Butane, etc. belong to same homologous series.

Properties of Compounds of Same Homologous Series



Copyright © excellup 2014