Carbon and its Compounds ||Class 10 || Science || CBSE Notes
Dear Students, Today we are going to share the Notes of Carbon and its Compound. These notes are prepared by the experienced teachers. These notes are free to all the students. These notes has been prepared according to the CCE pattern of school education based on NCERT Syllabus prescribed by the Central Board of School Education for Class X. All the important topics are covered in these notes.
Some Important Topics
F Interesting Facts about Carbon
F Carbon always formed covalent Bonds
F Carbon is Tetravalent
F Self combination/Catenation
F Occurrence of Carbon
E In free state
E In combined state
F Allotrophy
E Diamond
E Graphite
E Buckminster
fullerene
F Diamond
E Structure of diamond
E Uses of Diamond
F Graphite
E Structure of graphite
E Uses of Graphite
F Buckminster fullerene
F Organic Chemistry
F Organic compound
F Types of organic compounds
E Hydrocarbons
E Haloalkanes
E AlcohalsKetones
E Aldehydes
E Carboxylic acid
E Reason for large number of organic
compounds
F Hydrocarbon
E Saturated Hydrocarbon
E Unsaturated Hydrocarbon
F Alkenes
F Alkynes
E Structural and Electronic Formula
F Alkyl Groups
F Cyclic Hydrocarbons
F Naming of Hydrocarbons
E Single bond
E Double bond
E Triple bond
F Isomerism
F Homologous Series
E Homologous series of alkanes
E Homologous Series of alkenes
E Homologous Series of alkynes
Interesting Facts about Carbon
|
|
Name
|
Carbon
|
Symbol
|
C
|
Status
|
Non-Metal
|
Atomic
Number
|
6
|
Electronic
Configuration
|
2,
4
|
No.
of Valence electrons
|
4
|
No.
of electrons required to attain Nobel gas configuration
|
4
|
Valency
|
4 (Tetravalent)
|
Atomic
Mass
|
12
unit
|
Position
in group in M.P.T
|
14th
|
Position
in period in M.P.T
|
2nd
|
Bond
formed
|
Covalent Bond
|
Crystalline
allotrophs
|
Diamond,
Graphite, Buckminster fullerence
|
Carbon always formed covalent Bonds:-
The electronic configuration of
carbon is 2, 4 . It is clear that it should either loose 4 electrons or gain 4
electrons to achieve the inert gas electron configuration.
Since carbon atom is
very small. So, its electrons are strongly held by the nucleus. So, it is not
possible to remove 4 electrons from a carbon atom to give it the inert gas
electron arrangement. It is also not possible to add as many as 4 electrons to
a carbon atom due to energy considerations.
Since Carbon atoms can
achieve the inert gas electron arrangement only by the sharing of electrons,
therefore Carbon always form Covalent
Bonds.
Carbon is Tetravalent:
Since one carbon atom
required 4 electrons to achieve the eight- electron inert gas structure, therefore the valency of carbon is
4. That is carbon is tetravalent ( tetra
= four , valent = valency ). It is represented as
The most outstanding or unique
property of carbon its ability to combine with itself, atom to atom to form
long chain.
For example
Octane( C8H18 ) one of the constituent of petrol has a chain
of 8 carbon atoms. This property of carbon is also known as catenation.
It has tendency to
form long chains, branched chains and rings through covalent linkage. e.g.
Occurrence of Carbon:
Carbon is unreactive element and is found in free as well as
combined state.
(1) In free state:- Carbon occur in nature mainly in two forms ; diamond and
graphite. Another naturally occurring form of carbon called
Buckminsterfullerene has been discovered recently. Please note that only a
small amount of carbon occur as free element in the earth crust. Most of the
carbon occurs as free elements in the earth crust. Most of Carbon occurs in the
combined state.
(2) In combined state :- Carbon occurs in
nature in the form of compounds such as :- (1) Carbon dioxide gas
(2)
Carbonates like limestone marble and chalk
(3)Fossil fuel like Coal, Petroleum
and natural gas.
(4) Organic compounds
such as carbohydrate, fat, protein.
(5) Wood, cotton and
wool etc.
Allotrophy:-
It is the phenomena of existence of a chemical element in
two or more form called allotropes having similar chemical properties but
different physical properties which is due to the difference in their
structure. E.g. allotropes of Carbon
(1) Diamond
(2) Graphite
(3) Buckminster
fullerene
Diamond and graphite are the two
common allotropes of carbon which are known to us from centuries. Buckminster
fullerene is the new allotrope of carbon which has been discovered recently.
Diamond :- Diamond is a
colourless transparent substance have extraordinary brilliant shine
(chamak). Diamond is quite heavy and
extremely hard.It is the hardest known substance. It does not conduct
electricity.
Diamond burn on strong
heating to produce carbon dioxide. If we burn diamond in air, then only Carbon
dioxide gas is formed and nothing is
left behind. This shows that diamond is made up of carbon only.
Structure of diamond :-
A diamond crystal is a
giants molecule of carbon atoms.
The diamond crystal is
therefore made up of carbon atoms which are powerful bonded to one another by
network of covalent bonds.Due to this, the Diamond structure is very rigid. The
rigid structure of diamond make it very hard structure.
The compact and rigid
three dimensional arrangement of carbon
atoms in diamond gives it is a very density. The melting point of diamond is
also very high, being more than 3500 degree Celsius.
Diamond is also bad
conductor of electricity, because the four valence electrons of diamond used up
in forming the bonds.
Uses of Diamond:
(1) It is used for
cutting and grinding other hard materials,
and also used for drilling holes in the earth’s rocky layers.
(2) Diamond are used in cutting instrument
like glass.
Diamond dies are also used for drawing thin wires like
tungsten filament of the electric bulb.
(3) Diamond are used
for making jewellery.
(4) Sharp edged diamond
are used by eye surgeon as a tool to remove cataract from eyes with great
precision.
(5) Diamonds can also
be made artificially by subjecting pure carbon to very high pressure and
temperature.
Graphite :
Graphite is a greyish black diamond. Graphite is soft and
slippery to touch and it conducts electricity. If we burn graphite in oxygen
then only carbon dioxide gas is formed and nothing is left behind.
Structure of graphite:-
The structure of
graphite is very different from that of diamond. A graphite crystal consists of
carbon atoms layer or consists of sheet
of carbon atoms.
Each carbon atom in
graphite is joined to three other carbon atom to form flat hexagonal ring by
strong covalent bonds. Due to sheet like structure graphite is a comparatively
soft substance. Due to the presence of free electron that conduct electricity.
Uses of Graphite:
(1) Due to its
softness,powdered graphite is used as a lubricant for the fast moving parts of
the machinery.
(2) Graphite is used for
making carbon electrode or graphite electrodes in dry cell and electric arcs.
(3) Graphite is used for
making the core of our pencil lead and black paint.
Buckminster fullerene: Buckminster fullerene is an allotrope of carbon
containing clusters of 60 carbon atoms joined together to form spherical
molecules.
Buckminster fullerene
is a dark solid at room temperature.Itdiffers from other two are allotropes of
Carbon, diamond and graphite as it is very small molecule made of only 60 carbon atom.
Organic Chemistry
It is the branch of
Chemistry that deal with the study of organic compounds.
Organic compound :- The compound of carbon are known as organic compound expect
carbonate, bicarbonate , carbide and oxide.
Some example of
organic compounds:- Methane Ethane
methane ethanol ethanol etc.
Most of the carbon
compound are not conductor of electricity.
Some of organic compounds
(1) Plants
they give a sugar starch cellulose drugs vegetable oil insecticide which all
are organic compound.
(2) Animal they give us fat protein and oil.
(3) Coal Coal tar from coal gives us
organic Compound such as Benzene Nephthelene by its destructive distillation.
(4) Petroleum:- Petroleum oil give us organic compound like petrol diesel
kerosene etc.
(5) Dead remains :- Dead remains of living organisms give us organic Compounds
Types of organic compounds.
Some of the common
type of organic compound are
(a) Hydrocarbons
(b) Haloalkanes
(c) AlcohalsKetones
(d) Aldehydes
(e) Carboxylic acid
(organic acid)
Reason for large number of organic compounds
The two main reason
for large number of organic compound are(1) catenation and (2) tetravalency.
One reason for the
existence of a large number of organic compounds or carbon compound is that the
carbon atom can link with one another by mean of covalent bond to form a long
chain which is also known as catenation.
e.g.
Another reason for the
existence of large numbers of organic compounds that the valency of carbon is 4 and energy consideration
indicate that it is the loss or gain of 4 electrons is difficult.Due to the
reason carbon always form covalent bond by sharing its valency electrons with
atom of other element or with itself.
Hydrocarbon:
Compound which
contain hydrogen and contain carbon only are called hydrocarbon. Petroleum and
natural gas are the main source of hydrocarbons. For example:- Methane Ethane
propane butane pentane hexane etc.
Classification of Hydrocarbon
Saturated Hydrocarbon: Hydrocarbon in which carbon atom are connected by only
single bond is called a saturated
hydrocarbon (Alkanes)
General
Name
|
Alkanes
|
General
Formula
|
CnH2n
+ 2
|
Primary
|
―
ane
|
Example:- CH4 (Methane), C2H6
(Ethane), C3H8 (Propane)
Unsaturated Hydrocarbon: A hydrocarbon in which the two carbon atom are
connected by a double bond or a triple bond is called an unsaturated hydrocarbon. E.g. Ethane (C2H4)
and ethyne (C2H4).
Unsaturated hydrocarbon
are of two types
(1) Alkenes
(2) Alkynes
(1) Alkenes:- An unsaturated hydrocarbon in which that two carbon atoms
are connected by a double bond is known as alkenes. The general formula of
alkenes is CnH2n
where “n” is the number of carbon
atom in its one molecule structure of an alkenes Ethane is as follows:
Contain double bond (=)
Ethene (C2H4).
(2) Alkynes:- An unsaturated hydrocarbon in which the two carbon atom
are connected by a triple bond is called alkyne. The general formula of alkyne
is CnH2n-2 ,where
n is a number of carbon atoms in one molecule. Structure formula of alkyne is
as follows:-
H ➖ C ☰ C ➖ H
Ethyne contain trople bond (º)
Number
of
Carbon
Atoms
|
Word
root
|
1
|
Meth
|
2
|
Eth
|
3
|
Prop
|
4
|
But
|
5
|
Pent
|
6
|
Hex
|
7
|
Hept
|
8
|
Oct
|
9
|
Non
|
10
|
Dec
|
11
|
Undec
|
12
|
Dodec
|
Structural and Electronic Formula of Some Hydrocarbons
Ethane:-
Ethyne:
Ethene:
Point to remember:-
Ethane as CH3 ― H3C or H3C ― CH3
both are same.
Alkyl Groups:- The group formed by the removal of one hydrogen atom from
an alkane molecules is called an alkyl group. Example of alkyl group or methyl
(CH3‾) and Ethyl group ( C2H5‾) etc.
Please note that the
free line (―) shown on the carbon atom of a alkyl group means that one valency
of carbon atom is free in an alkyl group.
Cyclic Hydrocarbons
In order to the straight
chain hydrocarbons and branched chain hydrocarbons there are some other
hydrocarbons in which the carbon atoms are arranged in the form of a ring. Such
hydrocarbon are called cyclic hydrocarbon. The cyclic hydrocarbon may be
saturated or unsaturated.
(1) A Saturated Hydrocarbon
is cyclohexane. The formula of cyclohexane is C6H12
A molecule of cyclohexane
contain 6 carbon atom arranged in a hexagon ring with each carbon atom having
two hydrogen atom attached to it. The
structural formula of cyclohexane is shown in figure:
The saturated cyclic
hydrocarbons are called cycloalkanes. Cycloalkanes with having 3 carbon atom in
the ring is called cyclopropane (C3H6). The
cycloalkanes with 4 carbon atom in the ring is called Cyclobutane ( C4H8).
†
Please note that the general formula of the cycloalkanes is CnH2n , which is
same as that of alkenes.
(2) An unsaturated
cyclic hydrocarbon is benzene. The formula for benzene is C6H6.
A molecule of benzene is made up of 6 carbon atoms and 6 hydrogen atoms. Structure
formula is as shown in figure.
The unsaturated cyclic
compound like benzene are called aromatic compounds.
Naming of Hydrocarbons
Organic compounds have
two name : Common name and Official name.
The official name or systematic name
of organic compounds was given by International Union of Pure and Applied Chemistry (IUPAC) in 1958. The following number of things we keep in mind.
(1) The number of
carbon atom in a hydrocarbon is indicated by using the following steps.
One atom of carbon is
indicated by “Meth”
Two atom of carbon is
indicated by “Eth”
Three atom of carbon
is indicated by “Prop”
Four atom of carbon is
indicated by “But”
Five atom of carbon is
indicated by “Pent”
Six atom of carbon is
indicated by “Hex”
Seven atom of carbon
is indicated by “Hept”
Eight atom of carbon
is indicated by “Oct”
Nine atom of carbon is
indicated by “Non”
Ten atom of carbon is
indicated by “Dec”
(1) A saturated
hydrocarbon containing single bond
is indicated by writing the word one
after the stem.
(2) An unsaturated
hydrocarbon containing a double bond
is indicated by writing the word ene
after the stem.
(3) An unsaturated
hydrocarbon contain a triple bond
is indicated by writing the word yne after the stem.
Naming of Saturated Hydrocarbons
(1) Naming of CH4
:- The structure is given below
Since the compound
contain one carbon atom (Meth) and
single bond (saturated) hydrocarbon and indicated by ending ane.
Therefore, IUPAC name
become methane (meth + ane = Methane).
The common name of CH4
is also Methane.
(2) Naming of C2H6
:- The structure formula of C2H6 is given below
Similarly IUPAC name
of
(iii) C3H8
IUPAC name:- Propane
(iii) C3H8
Common name:- Propane
(iv) C4H10
(iv) C4H10
IUPAC name:- Butane
Common name:- n-Butane
(v) C5H12
IUPAC name:- Pentane
Common name:-
n-Pentane
IUPAC Nomenclature for
Branched Chain Saturated Hydrocarbons
We should remember the
following rules:-
(1) The longest chain
of carbon atoms in the structure of compound is found first and name as
derivative of alkanes. This is parent hydrocarbon.
(2) The alkyl group
present as side chains are considered as substituent and named separately
as methyl (CH3‾) and Ethyl
group ( C2H5‾) .
(3) The carbon atoms
of the longest carbon atom are numbered in such a way that the alkyl group get
the lowest possible number.
(4) The position of
the alkyl group is indicated by writing a number of carbon atom to which it is
attached.
(5) The IUPAC name of
the compound is obtained by writing the position and name of parent
hydrocarbon.
IUPAC name of C4 H10 :-
IUPAC name:- 2
methylpropane
Common name:- Iso
butane
IUPAC name of C5H12 :-
IUPAC name:- 2
methylbutane
Common name:- Iso
pentane
Naming of unsaturated hydrocarbon having double bond
Naming of C2H4
Common name:- Ethylene
Naming of C3H6
IUPAC name:- Propane
Common name:-
Propylene.
Naming of unsaturated hydrocarbon having Triple Bond
Naming of C2H2
IUPAC name:- Ethyne
Common name:-
Acetylene
Naming of C3H4
IUPAC name:- Propyne
Common name:- Methyl
acetylene.
Isomerism :
It is the
phenomena of existence of a chemical compound in two or more forms called
isomers having same molecular formula but different structural formula.
It should be notes
that as the number of carbon atoms in an organic compound increase, the number
of possible isomers increases rapidly.
Example:
(a) Isomers of
Butane:-
(n-butane C4H10)
(b) Similarly Isomers of pentane (C5H12)
Iso-pentane
2-methylbutane
Neopentane
2, 2-diamethylpropane
Isomers of Hexane: -
(C6H14)
Homologous Series:
A
homologous series is a group of organic compound having similar structure and
similar chemical properties in which the successive compound differ by CH2
group.
The various organic
compound of a homologous series are homologues.
Example of Homologous Series:-All the alkanes have the similar
structures with single covalent bond and show similar chemical properties. So
they can be grouped together in the form of homologous series.
The first five members
of homologous series of alkanes are given below.
(1) Methane
|
CH4
|
(2) Ethane
|
C2H6
|
(3) Propane
|
C3H8
|
(4) Butane
|
C4H10
|
(5) Pentane
|
C5H12
|
Homologous Series of
alkenes:-
(1) Ethene
|
C2H4
|
(2) Propene
|
C3H6
|
(3) Butene
|
C4H8
|
(4) Pentene
|
C5H10
|
(5) Hexene
|
C6H12
|
Homologous Series of
alkynes:-
(1) Ethyne
|
C2H2
|
(2) Propyne
|
C3H4
|
(3) Butyne
|
C4H6
|
(4) Pentyne
|
C5H8
|
(5) Hexyne
|
C6H10
|
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