NCERT Solutions of Carbon and its Compounds Class 10
<< Unsaturated Hydrocarbons : Alkene and AlkyneChemical Properties of Carbon Compounds >>

Class Ten CBSE NCERT

Carbon and Its Compounds

Carbon: Functional Group And Nomenclature of Hydrocarbon

Functional Group:

Single atom or group of atoms, that have similar chemical properties are called functional group. For example: Halogen group, Carboxyl group, Aldehyde group, etc.

Alkyl group: -R is known as alkyl group.


Halogen group: Halogen group is also known as halo group. –Cl (Chloro),-Br(Bromo),-I(Iodo) are halogen or halo group.

Alcohol: -OH is known as alcohol group.

Aldehyde: -CHO is known as aldehyde group.


Hydrocarbons belong to same group have similar properties.

Nomenclature of Carbon Compounds:

International Union of Pure and Applied Chemistry (IUPAC) decided some rules to name the carbon compounds. This was done to maintain the uniformity throughout the world. Names which are given on this basis are popularly known as IUPAC name.

(1) Identify the number of carbon atoms in carbon compound. Name the carbon compounds according to the number of carbon atoms.

Example:-

Saturated hydrocarbon having one carbon atom is named as Methane. Saturated hydrocarbon having two carbon atoms is named as Ethane.

Unsaturated hydrocarbon with double bond having two carbon atoms is named as Ethene.

Unsaturated hydrocarbon with triple bond between carbon atoms is named as Ethyne.

(2) If the structure has branched chain, identify the longest chain and then identify the number of carbon atoms.


In figure (a) the longest chain has eight carbon atoms, and thus the name of parent compound would be octane. In figure (b) longest chain has nine carbon atoms, and thus the name of parent compound would be nonane.


Identify the longest chain. Then number the carbon atoms in such a fashion that the functional group; if any; would come at the lowest number.

In the given figure (c), while counting from right to left (in red color), branched chain which is functional group falls at the fourth position. On the other hand, while counting from left to right, the branched chain falls at the fifth position. In this case, the numbering from right to left is taken because then only the functional would be at the lowest position.

(3) In case of a functional group present, write the prefix or suffix of the functional group according to the table given here. Then write the name of the parent compound.


Nomenclature of Alkane:-

Example – (1)


Common name:- Iso-butane.

IUPAC Name:

Number of carbon atoms in the longest chain = 3.

A methyl group is present at carbon number 2.

So, IUPAC Name is 2-methyl propane.

Example:- (2) -


It’s common name is Iso-pentane.

IUPAC Name:

Numbering of carbon atoms is done in two ways, i.e. from left to right and from right to left.

The number of carbon atoms in the longest chain = 4.

A methyl group (functional group) is attached with this chain.

Thus, name of parent compound is Butane.

In the numbering from left to right functional group falls at second number while in the numbering from right to left; the functional group falls at 3rd position.

Therefore, IUPAC name of this compound is 2-methyl butane.

Example:(3):-


Common name: NeopentaneAC Name: There are three carbon atoms in longest chain.

Two methyl groups are present at second (2) carbon atom. (Di is used as prefix for two).

Therefore, IUPAC Name: Di-methyl propane.

Naming of hydrocarbon with Halo group:


Common name: Methyl chloride

There is one carbon atom in this compound. So its parent name is Methane.

One chloro group is present in this compound.

So, its IUPAC name is Chloro-methane.


Common Name: Propyl chloride. AC Name:

Number of carbon atoms = 3

Functional group: Chloro

Thus, IUPAC Name is Chloro-propane.


Common name: Propyl brominde

IUPAC Name: Bromo-propane


Number of carbon atoms: 6 (six) ctional group: Iodo

Common Name: Hexyl iodide.

IUPAC Name: Iodo-hexane.


Number of carbon atom: 1 (one)

Functional group: Alcohol (suffix : ol)

Common name: Methyl alcohol.

IUPAC Name:

Methane e Methane – e + ol = Methanol.


Number of carbon atoms: 2 (two)

Functional group: Alcohol

Common name: Ethyl alcohol.

IUPAC Name: EthanoIUPAC Name: Ethanol.


Number of carbon atoms: 6 (six) l group: Alcohol

Common name: Hexyl alcohol.

IUPAC IUPAC Name: Hexanol.

Naming of Aldehyde group (-CHO):

The suffix of aldehyde group is “al”.

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

Alkane – e + al = Alkanal

Methane e + al = Methanal

Ethane e + al = Ethanal, and so on.


Number of carbon atom: 1 (one)

IUPAC Name: Methanal

Common name: Formaldehyde.


Number of carbon atoms: 2 (Two)

Functional group: Aldehyde

IUPAC Name: Ethanal

Common name: Acetaldehyde


Number of carbon atoms: 7 (seven) C Number of carbon atoms: 7 (seven) C Name: Heptanal.

Naming of Carboxylic Acid (– COOH):

Suffix for carboxylic acid is ‘oic acid”.

Thus an alkane having carboxylic acid is named as: >Example:

Methane e + oic acid = Methanoic acid

Ethane e + oic acid = Ethanoic acid.


Number of carbon atom: 1(one)

IUPAC Name: Methanoic acid.

Common name: Formic acid.


Number of carbon atoms: 2 (two)

Common Name: Acetic acid.

IUPAC Name: Ethanoic Acid


Number of carbon atoms: 5 (five)

Functional group present: Carboxylic acid

IUPAC Name: Pentanoic acid.

Naming of Ketone (– CO –):

Suffix for ketone group: ‘one’.

A hydrocarbon having ketone group is named as:


Number of carbon atoms: 3 (three)

Functional group: Ketone group

Thus, IUPAC Name is Propanone.

Common name: Dimethyl ketone.


Number of carbon atoms: 5 (five)

Functional group: Ketone group

Thus, IUPAC Name: Pentanone

General name: Diethyl ketone


Number of carbon atoms: 6 (six)

IUPAC Name: Hexanone

General name: Ethyl propyl ketone

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.


Similarly, all alkenes and alkSimilarly, all alkenes and alkynes belong to same homologous series.

Properties of Compounds of Same Homologous Series

(a) Compounds of same homologous series have same general formula.

(b) Compounds of same homologous series differ from their consecutive members by one carbon atom and two hydrogen atoms, homologous series differ from their consecutive members by one carbon atom and two hydrogen atoms, i.e. by CH2

(d) Compounds of same homologous series have same chemical properties.

(e)Compounds of same homologous series differ by physical properties with increase or decrease in molecular mass.


      

NCERT Solutions of Carbon and its Compounds Class 10
<< Unsaturated Hydrocarbons : Alkene and AlkyneChemical Properties of Carbon Compounds >>

Class Ten CBSE NCERT will be available online in PDF book form soon. The solutions are absolutely Free. Soon you will be able to download the solutions.