L-4 Carbon and its compounds
Covalent Bond:
The chemical bond formed by the sharing of electrons between two atoms is known as
covalent bond
The sharing of electrons takes place in such a way that each atom in the resulting
molecule gets the stable electron configuration of inert gases.
Whenever a non metal combines with another non metal sharing of electrons takes
place between their atoms.
The bond formed between the atoms of the same element is a covalent bond.
The shared electrons are counted with both the atoms due to which each atom in the
resulting molecules gets an inert gas electron arrangement of either 8 electrons or 2
electrons in the outermost shell.
Types of covalent bond :
i. Single covalent bond
ii. Double covalent bond
iii. Triple covalent bond
i. Single covalent bond
Single covalent bond or single bond is formed by the sharing of one pair of electrons
between two atoms.
A single covalent bond is denoted by putting a short line (-) between two atoms.
Formation of Hydrogen Molecule
Hydrogen atom has only one electron in its outermost shell, and requires one more to acquire the
nearest noble gas configuration of helium (He: 1s2).
To do so, two hydrogen atoms contribute one electron each to share one pair of electrons
between them. This leads to the formation of a single covalent bond between the two hydrogen
atoms.
Formation of Chlorine Molecule
Chlorine atom has seven valence electrons. Thus, each Cl atom requires one more electron to
acquire the nearest noble gas configuration (Ar:2, 8, 8). They do this by mutual sharing of one
pair of electrons as shown below.
Formation of Methane (CH4)
Carbon atom has four electrons in its outermost shell. Thus, it requires four more electrons to
acquire a stable noble gas configuration. Each hydrogen atom has only one electron in its
outermost shell and requires one more electron to complete its outermost shell (to acquire He
configuration). This is done as follows:
Formation of ethane – C2H6
2. Double covalent bond
Double covalent bond is formed by the sharing of two pairs of electrons between two
atoms.
A double covalent bond is denoted by putting 2 short line (=) between two atoms.
Formation of CO2 :
Formation of O2
Formation of C2H4
Electronic configuration of C = K L
2 4
Electronic configuration of H = K
1
3. Triple covalent bond :
Triple covalent bond is denoted by putting 3 short lines (  ) between the two atoms.
Eg:
a. Formation of N2 :
Electronic configuration of N = K
2
L
5
b. Formation of ethyne ( C2H2) ;
Electronic configuration of C = K L
2 4
Electronic configuration of H = K
1
Properties of covalent compounds :
1. Covalent compounds are usually liquids and gases . only a few of them are solids.
Solid covalent compounds
i. Iodine ii. Glucose iii.Naphthalene iv.Camphor
Liquid covalent compounds
i. Methane ii. Propane
2. They usually have low melting and low boiling points.
3. They are insoluble in water but they are soluble in organic solvents.
4. They do not conduct electricity
Carbon compounds :
Carbon is an element (a non metal). It belongs to 2nd period, 14th group of the periodic
table.
Carbon derived its name from the Latin word carbo means coal.
Atomic number of carbon is 6
Electronic configuration is
K L
2 4
hence carbon is tetravalent.
Availability of Carbon in earth’s crust is 0.02% in the form of minerals like CO3 an HCO3.
Availability of carbon in the atmosphere is 0.03% in the form of CO2
More than 5 million carbon compounds are known to chemists
Carbon has four electrons in its outermost shell and needs to gain or lose 4 electrons to
attain noble gas configuration. If it were to gain or loose electrons
i. It could gain 4 electrons to form C4- anion but it would be difficult for the nucleus
with 6 protons to hold on to 10 electrons.
ii. It could loose 4 electrons forming C4+ cation but it would requires a large amount of
energy to remove 4 electrons leaving behind a carbon cation with 6 protons in its
nucleus holding on to 2 electrons.
Carbon overcomes this problem by sharing its electrons with other atoms of carbon or
with atoms of other elements.
Versatile nature or unique nature of carbon :
Carbon shows unique properties like tetravalency, catenation, formation of multiple
bonds and most of its compounds form isomers.
Catenation :
The property of self linking of carbon atom through covalent bonds in order to form
straight or branched chains and rings of different sizes is known as catenation.
Eg:
Carbon atom poses the property of catenation to a greater extent than any other
element.
Tetravalency of Carbon :
Carbon has four electrons, it can neither loose nor gain electrons to attain octet, it forms
covalent bonds by sharing its 4 electrons with other carbon atoms or atoms of other
elements.
“The characteristic property of carbon atom by virtue of which it form four covalent
bonds is called tetravalency of carbon atom.”
Carbon form compounds with oxygen, hydrogen, nitrogen, sulphur, halogens and many
other elements.
Carbon forms very strong bonds with most other elements making these compounds
exceptionally stable.
The reason for the formation of strong bonds by carbon is its small size. This enables
the nucleus of the carbon atom to hold on to the shared pair of electrons strongly.
Tendency to form multiple bonds :
Due to small size, carbon atom forms double or triple bonds. As a result It can form
variety of compounds.
Isomerism:
The organic compounds having same molecular formula but different structural
formulae are called isomers and the phenomenon is isomerism.
Organic compounds with minimum 4 carbon atoms show the phenomena isomerism
Hydrocarbons :
A compound made up of hydrogen and carbon only is called hydrocarbon
E.g. Methane
Ethane
Ethene
Ethyne
CH4
C2H6
C2H4
C2H2
The carbon atoms are arranged in hydrocarbons in straight chain, branched chain or
ringed structures.
Hydrocarbons
Cyclic
hydrocarbons
Aliphatic
hydrocarbons
Saturated
Alkane
Alicyclic
Unsaturated
Alkeness
Aromatic
Alkynes
 Aliphatic hydrocarbons :
The hydrocarbons in which carbon atoms are arranged in straight or branched chains
are called aliphatic hydrocarbons
Aliphatic hydrocarbons are of two types:
a. saturated aliphatic hydrocarbons
b. Unsaturated aliphatic hydrocarbons.
Saturated hydrocarbons (Alkanes)
A hydrocarbon in which the carbon atoms are connected by only single bonds is called
saturated hydrocarbons.
Saturated hydrocarbons are called alkanes and are also called paraffins
Param - Little
Affin
-
Affinity
Eg : Methane ,CH4 ,
Ethane ; C2H6
Propane : C3H8
Condensed structure : CH3CH2CH3
Butane : C4H10
Condensed structure CH3CH2CH2CH3
The general formula of alkanes is CnH2n+2
The saturated hydrocarbons are chemically not reactive
Unsaturated hydrocarbons
Hydrocarbons in which the two carbon atoms are connected by a double bond or a triple
bond then these hydrocarbons are called unsaturated hydrocarbons
Alkenes:
An unsaturated hydrocarbon in which the two carbon atoms are connected by a double
bond is called alkene.
Eg: Ethene C2H4
:
Propene C3H6
Condensed formula : CH3CH=CH2
Butene C4H8
Structural formula
:
Condensed formula :
CH3 CH2 CHCH2
Alkenes contain –C=C-- group



The general form of alkene is CnH2n. Alkenes are also called olefins.
Since an alkene has double bond between two carbon atoms, simplest alkene
will have two carbon atom in its molecule.
There can be no alkene having only one carbon atom.
ii. Alkynes :
An unsaturated hydrocarbon in which two carbon atoms are connected by a triple bond
is called an alkyne.
Eg:
Ethyne C2H2
Propyne C3H4
Butyne
C4H6
An alkyne contains –C  C – graph. General form of alkyne CnH2n-2
Unsaturated hydrocarbons (Alkenes, Alkynes) are more reactive than saturated
hydrocarbons (Alkanes)
Alkyl group:
The group formed by the removal of one hydrogen atom from an alkane molecule is
called an alkyl group
Eg:
CH4
Methyl group
C2H6
Ethyl group
C3H8
Propyl group
The alkyl groups are denoted by R. The general formula of alkyl group is CnH2n+1
One valancy of carbon atom is free in an alkyl group
Write the structure, electron dot structure, formula of ethane, ehene, ethyne
i. Ethane
C2H6
ii. Ethene
iii. Ethyne
C2H4
C2H2
b.Cyclic hydrocarbons :
The hydrocarbons in which the carbon atoms are arranged in form of closed chains or
rings.
The cyclic hydrocarbons may be saturated or unsaturated.
They are classified as
Alicyclic hydrocarbons
Aromatic hydrocarbons
Alicyclic hydrocarbons :
These hydrocarbons contain a ring chain of three or more carbon atoms. This cyclic
compounds are named by prefixing “cyclo” before the name of the corresponding
straight chain hydrocarbon
i. Saturated
Cyclo propane
Cyclo Butane
CycloPentane
Cyclohexane
Unsaturated
e.g.: Cyclopropene
cyclopentene
cyclobutene
cylcohexene
Cyclobutyne
Aromatic Hydrocarbons:
The hydrocarbons contain at least benzene ring in their molecules. The benzene ring is
a specific type of ring structure of six carbon atoms having C-C single bond and C=C
double bond in alternate positions.
Toluene
Phenol
Naphthalene
Hetero atoms:
The atom replacing the hydrogen atom in an organic compound is called hetero in an
organic compound is called hetero atoms.
These hetero atoms give characteristic properties to compounds regardless the length
and nature of carbon atom.
Functional group :
A functional group be defined as an atom or group of atoms which determine the
properties of organic compounds.

The functional group is the site of chemical reactivity in the organic molecule
Homologous series :
A series of organic compounds having similar structures and similar chemical properties
in which the successive members differ in their molecular formula by CH2 group.
The different members of the series are called homologous
Eg: An alkane family represents a homologous series.
All the alkanes have similar structure with the single covalent bond and show similar
chemical properties. Each successive members differ by a CH2 group
Methane –CH4
Ethane - C2H6
Propane –C3H8
Butane – C4H10
Similarly alkene and alkyne family also represent homologous series.
Alkene
Alkyne
Ethane - C2H6
Propane – C3H8
Butane – C4H10
Ethyne – C2H2
Propyne - C3H4
Butyne – C4H6
Homologous series of alcohol is as follows
CH3OH
C2H5OH
C3H7OH
Characteristics of homologous series :
1. All the members of homologous series can be represented by the same general
formula
Alkane – CnH2n+2
Alkene – CnH2n
Alkyne – Cnh2n-2
Alcohol – R – OH
2. Any two adjacent homologous differ by a-CH2 group.
3. The difference in the molecular masses of any two adjacent members is 14u
4. All the members of homologous series have similar chemical properties due to
similar structural formula.
5. The members of a homologous series show a gradual change in their physical
properties such as melting points, boiling points, density, solubility etc. on going
from higher to lower molecular series
Simple rules for nomenclature of organic compounds :
How to name organic compounds using the IUPAC rules
In order to name organic compounds you must first memorize a few basic
names. These names are listed within the discussion of naming alkanes. In
general, the base part of the name reflects the number of carbons in what you
have assigned to be the parent chain. The suffix of the name reflects the
type(s) of functional group(s) present on (or within) the parent chain. Other
groups which are attached to the parent chain are called substituents.


Alkanes - saturated hydrocarbons
The names of the straight chain saturated hydrocarbons for up to a 12
carbon chain are shown below. The names of the substituents formed by
the removal of one hydrogen from the end of the chain is obtained by
changing the suffix -ane to -yl.
Number of Carbons
Name
1
methane
2
ethane
3
propane
4
butane
5
pentane
6
hexane
7
heptane
8
octane
9
nonane
10
decane
11
undecane
12
dodecane
There are a few common branched substituents which you should
memorize. These are shown below.

Here is a simple list of rules to follow. Some examples are given at the
end of the list.
1. Identify the longest carbon chain. This chain is called the parent
chain.
2. Identify all of the substituents (groups appending from the parent
chain).
3. Number the carbons of the parent chain from the end that gives the
substituents the lowest numbers. When compairing a series of
numbers, the series that is the "lowest" is the one which contains
the lowest number at the occasion of the first difference. If two or
more side chains are in equivalent positions, assign the lowest
number to the one which will come first in the name.
4. If the same substituent occurs more than once, the location of each
point on which the substituent occurs is given. In addition, the
number of times the substituent group occurs is indicated by a
prefix (di, tri, tetra, etc.).
5. If there are two or more different substituents they are listed in
alphabetical order using the base name (ignore the prefixes). The
only prefix which is used when putting the substituents in
alphabetical order is iso as in isopropyl or isobutyl. The prefixes
sec- and tert- are not used in determining alphabetical order except
when compared with each other.
6. If chains of equal length are competing for selection as the parent
chain, then the choice goes in series to:
a) the chain which has the greatest number of side chains.
b) the chain whose substituents have the lowest- numbers.
c) the chain having the greatest number of carbon atoms in the
smaller side chain.
d)the chain having the least branched side chains.
7. A cyclic (ring) hydrocarbon is designated by the prefix cyclo- which
appears directly in front of the base name.
In summary, the name of the compound is written out with the substituents
in alphabetical order followed by the base name (derived from the number
of carbons in the parent chain). Commas are used between numbers and
dashes are used between letters and numbers. There are no spaces in
the name.
Here are some examples:
Alkyl halides
The halogen is treated as a substituent on an alkane chain. The halosubstituent is considered of equal rank with an alkyl substituent in the
numbering of the parent chain. The halogens are represented as follows:
F fluoroCl chloroBr bromoI



iodo-
Here are some examples:
Alkenes and Alkynes - unsaturated hydrocarbons
Double bonds in hydrocarbons are indicated by replacing the suffix -ane
with -ene. If there is more than one double bond, the suffix is expanded to
include a prefix that indicates the number of double bonds present (adiene, -atriene, etc.). Triple bonds are named in a similar way using the
suffix -yne. The position of the multiple bond(s) within the parent chain
is(are) indicated by placing the number(s) of the first carbon of the multiple
bond(s) directly in front of the base name.
Here is an important list of rules to follow:
1. The parent chain is numbered so that the multiple bonds have the
lowest numbers (double and triple bonds have priority over alkyl
and halo substituents).
2. When both double and triple bonds are present, numbers as low as
possible are given to double and triple bonds even though this may
at times give "-yne" a lower number than "-ene". When there is a
choice in numbering, the double bonds are given the lowest
numbers.
3. When both double and triple bonds are present, the -en suffix
follows the parent chain directly and the -yne suffix follows the -en
suffix (notice that the e is left off, -en instead of -ene). The location
of the double bond(s) is(are) indicated before the parent name as
before, and the location of the triple bond(s) is(are) indicated
between the -en and -yne suffixes. See below for examples.
4. For a branched unsaturated acyclic hydrocarbon, the parent chain
is the longest carbon chain that contains the maximum number of
double and triple bonds. If there are two or more chains
competing for selection as the parent chain (chain with the most
multiple bonds), the choice goes to (1) the chain with the greatest
number of carbon atoms, (2) the # of carbon atoms being equal, the
chain containing the maximum number of double bonds.
5. If there is a choice in numbering not previously covered, the parent
chain is numbered to give the substituents the lowest number at
the first point of difference.
Here are some examples:

Alcohols
Alcohols are named by replacing the suffix -ane with -anol. If there is
more than one hydroxyl group (-OH), the suffix is expanded to include a
prefix that indicates the number of hydroxyl groups present (-anediol, anetriol, etc.). The position of the hydroxyl group(s) on the parent chain
is(are) indicated by placing the number(s) corresponding to the location(s)
on the parent chain directly in front of the base name (same as alkenes).
Here is an important list of rules to follow:
1. The hydroxyl group takes precedence over alkyl groups and
halogen substituents, as well as double bonds, in the numbering of
the parent chain.
2. When both double bonds and hydroxyl groups are present, the -en
suffix follows the parent chain directly and the -ol suffix follows the en suffix (notice that the e is left off, -en instead of -ene). The
location of the double bond(s) is(are) indicated before the parent
name as before, and the location of the hydroxyl group(s) is(are)
indicated between the -en and -ol suffixes. See below for examples.
Again, the hydroxyl gets priority in the numbering of the parent
chain.
3. If there is a choice in numbering not previously covered, the parent
chain is numbered to give the substituents the lowest number at
the first point of difference.
Here are some examples:

Ethers
You are only expected to know how to name ethers by their commmon names.
The two alkyl groups attached to the oxygen are put in alphabetical order with
spaces between the names and they are followed by the word ether. The prefix
di- is used if both alkyl groups are the same.
Here are some examples:

Aldehydes
Aldehydes are named by replacing the suffix -ane with -anal. If there is
more than one -CHO group, the suffix is expanded to include a prefix that
indicates the number of -CHO groups present (-anedial - there should not
be more than 2 of these groups on the parent chain as they must occur at
the ends). It is not necessary to indicate the position of the -CHO group
because this group will be at the end of the parent chain and its carbon is
automatically assigned as C-1.
Here is an important list of rules to follow:
1. The carbonyl group takes precedence over alkyl groups and
halogen substituents, as well as double bonds, in the numbering of
the parent chain.
2. When both double bonds and carbonyl groups are present, the -en
suffix follows the parent chain directly and the -al suffix follows the en suffix (notice that the e is left off, -en instead of -ene). The
location of the double bond(s) is(are) indicated before the parent
name as before, and the -al suffix follows the -en suffix directly.
Remember it is not necessary to specify the location of the carbonyl
group because it will automatically be carbon #1. See below for
examples. Again, the carbonyl gets priority in the numbering of the
parent chain.
3. There are a couple of common names which are acceptable as
IUPAC names. They are shown in the examples at the end of this
list but at this point these names will not be accepted by the
computer. Eventually they will be accepted.
4. If there is a choice in numbering not previously covered, the parent
chain is numbered to give the substituents the lowest number at
the first point of difference.
Here are some examples:

Ketones
Ketones are named by replacing the suffix -ane with -anone. If there is
more than one carbonyl group (C=O), the suffix is expanded to include a
prefix that indicates the number of carbonyl groups present (-anedione, anetrione, etc.). The position of the carbonyl group(s) on the parent chain
is(are) indicated by placing the number(s) corresponding to the location(s)
on the parent chain directly in front of the base name (same as alkenes).
Here is an important list of rules to follow:
1. The carbonyl group takes precedence over alkyl groups and
halogen substituents, as well as double bonds, in the numbering of
the parent chain.
2. When both double bonds and carbonyl groups are present, the -en
suffix follows the parent chain directly and the -one suffix follows
the -en suffix (notice that the e is left off, -en instead of -ene). The
location of the double bond(s) is(are) indicated before the parent
name as before, and the location of the carbonyl group(s) is(are)
indicated between the -en and -one suffixes. See below for
examples. Again, the carbonyl gets priority in the numbering of the
parent chain.
3. If there is a choice in numbering not previously covered, the parent
chain is numbered to give the substituents the lowest number at
the first point of difference.
Here are some examples:

Carboxylic Acids
Carboxylic acids are named by counting the number of carbons in the
longest continuous chain including the carboxyl group and by replacing
the suffix -ane of the corresponding alkane with -anoic acid. If there are
two -COOH groups, the suffix is expanded to include a prefix that
indicates the number of -COOH groups present (-anedioic acid - there
should not be more than 2 of these groups on the parent chain as they
must occur at the ends). It is not necessary to indicate the position of the COOH group because this group will be at the end of the parent chain and
its carbon is automatically assigned as C-1.
Here is an important list of rules to follow:
1. The carboxyl group takes precedence over alkyl groups and
halogen substituents, as well as double bonds, in the numbering of
the parent chain.
2. If the carboxyl group is attached to a ring the parent ring is named
and the suffix -carboxylic acid is added.
3. When both double bonds and carboxyl groups are present, the -en
suffix follows the parent chain directly and the -oic acid suffix
follows the -en suffix (notice that the e is left off, -en instead of ene). The location of the double bond(s) is(are) indicated before the
parent name as before, and the -oic acid suffix follows the -en suffix
directly. Remember it is not necessary to specify the location of the
carboxyl group because it will automatically be carbon #1. See
below for examples. Again, the carboxyl gets priority in the
numbering of the parent chain.
4. There are several common names which are acceptable as IUPAC
names. They are shown in the examples at the end of this list but
at this point these names will not be accepted by the computer.
Eventually they will be accepted.
5. If there is a choice in numbering not previously covered, the parent
chain is numbered to give the substituents the lowest number at
the first point of difference.
Here are some examples:

Esters
Systematic names of esters are based on the name of the corresponding
carboxylic acid. Remember esters look like this:
The alkyl group is named like a substituent using the -yl ending. This is
followed by a space. The acyl portion of the name (what is left over) is
named by replacing the -ic acid suffix of the corresponding carboxylic acid
with -ate.
Here are some examples:

Amines
You are only expected to know how to name amines by their common
names . They are named like ethers, the alkyl (R) groups attached to the
nitrogen are put in alphabetical order with no spaces between the names
and these are followed by the word amine. The prefixes di- and tri- are
used if two or three of the alkyl groups are the same.
NOTE: Some books put spaces between the parts of the name, but we will
not. Follow the examples.
Here are some examples:

Summary of functional groups
Functional group Prefix
Suffix
carboxylic acids
none
-oic acid
aldehydes
none
-al
ketones
none
-one
alchols
hydroxy-
-ol
amines
amino-
-amine
ethers
alkoxy-
-ether
fluorine
fluoro-
none
chlorine
chloro-
none
bromine
bromo-
none
iodine
iodo-
none
Rule – 1
Selection of carbon
Choose the longest carbon chain. The compound is then named as the derivative of the
alkane which corresponds to the longest chain.
Rule 2
The branched chains are considered to be substituents and their positions are
indicated by the number of carbon atoms to which they are attached.
Rule 3
The carbon atoms of the longest chain are numbered in such a way that the
substituents get the smallest possible number
Rule 4
In case any functional group is present in the chain the carbon atoms are numbered in
such a way that the functional group gets the smallest possible number.
Rule 5
In case of different substituents are attached to the chain they are arranged and named
alphabetically.
Rule 6
The positions of alkyl groups are indicated by writing the position and name of the alkyl
group just before the name of the parent carbon
Rule 7
Multiple alkyl groups are labeled with greek numerical prefixes such as di for 2, tri for 3,
tetra for 4, penta for 5
Chemical properties of carbon compounds:
1. Combustion or burning:
The process of burning a carbon compound in air to give CO2 , Water vapour, heat and
light is known as combustion.
Combustion is also called burning.
E.g.:
CH4 + 2O2  CO2 + 2H20 + Heat + Light
C2H4 + 3O2  2CO2 + 2H2O + Heat + light
CH3CH2OH + 3O2  2CO2 + 3H2o + Heat + Light
Note :
The major constituent of LPG is butane
The major constituent of CNG is methane
The saturated hydrocarbon generally burns with a blue non-sooty flame because the
percentage of carbon in the saturated hydrocarbons is comparatively low which gets
oxidized completely by the oxygen present in air
The unsaturated hydrocarbon (alkenes, alkynes) burn in air with a yellow sooty flame
because the percentage of carbon in unsaturated hydrocarbon is comparatively high
which does not get oxidized completely in air.
A mixture of acetylene and air is not used for welding because burning of acetylene in
air produces a sooty flame which is not hot enough to melt metals for welding.
If a mixture of acetylene and pure oxygen is burned then acetylene burns completely
producing a blue flame and the oxy acetylene flame is extremely hot and produces very
high temperature which is used for welding metals.
Disadvantages of incomplete combustion:

In complete combustion of fuels leads to un burnt carbon in the form of soot
which pollutes the atmosphere.

The incomplete combustion of fuel leads to the formation of extremely poisonous
gas CO.

Incomplete combustion produces less heat than that produced by complete
combustion.

Fuels such as coal, petroleum, etc have some amount of nitrogen and sulphur in
them. On heating they are converted into their oxides ( NO , SO2 ) which are
released in the atmosphere,. These are major pollutants.
2.Oxidation
Oxidation is the process in which oxygen is added to the substance.
Oxidation is a controlled combustion. Oxidation of carbon compounds gives different
products.
Eg:
Ethanol on treatment with alkaline KMnO4 or acidified K2Cr2O7 gives ethanoic acid.
alkaline
KMnO 4 CH COOH + H O
CH3CH2OH 
3
2
(ethanol)
(ethanoic acid)
On treatment with alkaline KMnO4 solution ethene is oxidized to ethylene glycol.
Ethyne on treatment with alkaline KMnO4 give oxalic acid
3. Substitution reaction
It is a characteristic property of alkanes. The reaction in which an atom or group of
atoms in a molecule is replaced by different atoms or group of atoms is called
substitution reactions.
Saturated hydrocarbons in presence of sunlight reacts with halogens.
Eg:
Sunlight
 CH3Cl + HCl
CH4 + Cl2 
(Chloromethane)
Sunlight
 CH2Cl2 + HCl
CH3Cl + Cl2 
(diChloromethane)
Sunlight
 CHCl3 + HCl
CH2Cl2 + Cl2 
(triChloromethane)
Sunlight
 CCl4 + HCl
CHCl3 + Cl2 
(tetraChloromethane)
4. Addition reaction:
The reaction in which an unsaturated hydrocarbon combines with another substance to
give a single product is called addition reaction
It is the characteristic property of unsaturated hydrocarbons.
Eg: Halogens add on to ehene at room temperature to form addition compound.
Eg: Addition of hydrogen
Hydrogen reacts with ethene in the presence of finely divided Nickel at 473 K to form
ethane
Hydrogenation :
The addition of hydrogen to an unsaturated hydrocarbon to obtain a saturated
hydrocarbon is called hydrogenation.
The process of hydrogenation has an important industrial application. It is used to
prepare vegetable ghee from vegetable oil.
Hydrogenation of oil
Vegetable oils like groundnut oil, cotton seed oil, mustard oil which are liquids at room
temperature are unsaturated fats having double bonds and triple bonds between some
of their atoms.
When a vegetable oil is heated with hydrogen in the presence of finely divided nickel as
catalyst then a saturated fat is called vegetable ghee is formed . This reaction is called
hydrogenation of oil.
Vegetable oils containing unsaturated fatty acids are good for health.
Test for unsaturated compounds:
When bromine water is added to an unsaturated compound the red brown colour of
bromine water is discharged. So if an organic compound decolourises bromine water it
will be an unsaturated compound otherwise it is a saturated hydrocarbon
Ethanol
Ethanol is the second and most important member of alcohol series
Chemical formula – C2H5OH or CH3CH2OH
Its common name is ethyl alcohol. The structural formula is
It is a constituent of alcoholic beverages such as beer, wine, whisky and cough syrups
and digestive syrups etc
Physical properties
1. Ethanol is a colourless liquid having pleasant smell and burning taste.
2. It has a boiling point of 78oC and 351 K.
3. It is miscible in water in all proportions.
Note:
The solubility of ethanol in water is due to the presence of hydroxyl groups.
4. Ethanol has no effect on any litmus solution. It is a neutral compound.
Absolute alcohol :
100 % pure ethanol is called absolute alcohol.
Rectified spirit
Ethanol containing 5% water is called rectified spirit.
The rectified spirit is the commercial alcohol
Chemical properties:
Ethanol is highly inflammable liquid and burns with oxygen with a pale blue oxygen
flame to produce CO2, H2O (vapour and a lot of heat and light)
C2H5OH + 3O2  2CO2 + 3H2O + Heat + Light
Ethanol is used as a additive in petrol
2. Reaction with Na metal:
Ethanol reacts with Na metal to form sodiumethoxide and H2 gas is liberated.
2CH3CH2OH + 2Na  2CH3CH2ONa + H2
This reaction is used as a test for alcohol.
Activity:
Take about 2ml of pure alcohol in a test tube and add a small piece of clean sodium
metal to it, rapid effervescence due to the evolution of hydrogen gas is produced. When
a burning splinter is brought near the mouth of the test tube the gas burns with a pop
sound which is a characteristic of hydrogen gas.
3. Oxidation:
When ethanol is heated with alkaline KMnO4 or acidified K2Cr2O7 it gets oxidized to
CH3COOH (ethanoic acid)
alkaline
KMnO 4 CH COOH + H O
CH3CH2OH + 2(O) 
3
2
Ethanol gets oxidized to ethanol with chromic anhydride.
Cr 2 O3in
C2H5OH 
CH 3COOH 
CH3CHO
4. Action with concentrated H2SO4 (dehydration)
Ethanol reacts with conc.H2SO4 at 443 K to produce unsaturated hydrocarbon ethene.
This reaction is known as acidic dehydration of ethanol
The con. H2SO4 is call dehydrating agent.
5. Reaction with ethanoic acid (esterification)
Ethanol reacts with ethanoic acid on warming in the presence of con. H2SO4 to form a
sweet smelling ester called ethylethanoate
C2H5OH + CH3COOH
ConH 2 SO 4



CH3COOC2H5 + H2O
The reaction in which a carboxylic acid combines with an alcohol in the presences of
con H2SO4 to form an ester is called esterification.
Activity:
1. Take 1 ml of ethanol and 1ml of glacial acetic acid along with a few drops of
concentrated H2SO4 in a test tube.
2. Warm in a water bath for at least 5 minutes
3. Pour the contents of test tube into a beaker containing 20 to 50 ml of water and
smell the resulting mixture.
4. A sweet smell is obtained indicating the formation of odour.
Tests for alcohol:
Sodium metal test
Add a small piece of Na metal to the organic liquid to be tested taken in a test tube. If
bubbles of H2 gas are produced it indicates that given organic liquid is a alcohol
Ester formation test
Warm the organic compound to be tested with a glacial acetic acid and few drops of
con. H2SO4. A sweet smell due to formation of ester indicates the presence of alcohol
Denatured alcohol:
It is 95% ethanol which is made unfit for drinking purpose by adding small quantities of
poisonous substances like methanol, pyridine, copper sulphate etc.,
Power alcohol:
It is a mixture of 20% ethanol and 50% gasoline and a solvent such as benzene, ether,
etc.,
It is a substitute for gasoline
ETHANOIC ACID
Ethanoic acid is the second member of homologous series of carboxylic acid. Its
chemical formula is CH3COOH.
Structural formula is
Its common name is acetic acid. 5 to 8% solution of ethanoic acid in water is called
vinegar.
Vinegar is widely used as a preservative in pickles.
The melting point of pure ethanoic acid is 290 K and hence it often freezes in cold
climates. Due to this pure ethanoic acid is called glacial ethanoic acid or glacial acetic
acid.
Physical Properties:
1. Ethanoic acid is colourless, corrosive liquid with sharp pungent odour of vinegar
2. It has a sour taste.
3. Its boiling point is 319 K (1180C)
4. It is miscible with water, ether, alcohol in all proportions.
Chemical properties:
1. Action on litmus
Being acidic in nature ethanoic acid turns blue litmus solution red. Dilute ethanoic acid
turns universal indicator orange showing that its pH is about 4.
2. Reaction with metals:
It reacts with metals such as Na, K, Mg, Al, etc to form metal ethanoate and liberate H2
gas
2CH3COOH + 2Na  2CH3COONa + H2 (g)
(Sodium ethanoate)
3. Reaction with carbonate :
When sodium carbonate is added to a solution of acetic acid brisk effervescence of CO2
is evolved
2CH3COOH + Na2CO3  2CH3COONa + CO2 + H2O
4. Reaction with bicarbonate:
Ethanoic acid reacts with sodium hydrogen carbonate to evolve brisk effervescence of
CO2 gas
2CH3COOH + NaHCO3  2CH3COONa + CO2 + H2O
5. Reaction with an alkali:
Ethanoic acid reacts with alkalis to form salt and water.
2CH3COOH + NaOH  2CH3COONa + H2O
6. Reaction with alcohol: (Esterification)
Ethanoic acid reacts with alcohols in the presence of concentrated H2SO4 to form esters
which have very pleasant odour
Conc
H 2SO 4 2CH COOC H + H O
2CH3COOH + C2H5OH 
3
2 5
2
(ethyl ethanoate)
7.Saponification
The alkaline hydrolysis of ester to give sodium salt of carboxylic acid and alcohol is
called saponification.

CH3COOC2H 5 + NaOH 
 2CH3COONa + C2H5OH
Tests for ethanoic acid
1. Litmus test
2. Sodium bicarbonate test
3. Ester test
Uses of ethanoic acid:
1. Dilute ethanoic acid in the form of vinegar is used as food preservative in the
preparation of pickles and sauces.
2. Ethanoic acid is used in preparation of dyes, plastics, pharmaceuticals
3. It is used in the manufacture of rubber and silk.
Classify the following compounds as alkanes, alkenes, alkynes. Write their IUPAC
name and common name
1. C2H2
- Alkyne
- Ethyne acetylene
2. C2H6 – Alkane
- Ethane
3. C2H4 – Alkene
- Ethene – Ethylene
4 C3H8 - Alkane
- propane
5. C3H4 – Alkyne
- propyne
Name the compound
CH3
|
1. CH3 – C – CH2 – CH3
2- Methyl butane
Write the structural formulae of two types of butane (C4H10). Write their common
names and IUPAC names
Write the structural formula of isomers of pentane and write IUPAC names:
Write the structural formula of isomers of hexane and write IUPAC names :
Soaps and Detergents :
Any substance which has cleaning action in water is called detergent.
There are two types of detergents.


Soapy detergent
Soap less / non-soapy detergents.
Soapy detergents are called soaps. Non soapy detergents are called synthetic
detergents or detergents.
Soaps:
Soap is the sodium/potassium salt of long chain fatty acids(carboxylic acid) which has
cleansing properties in water
Eg:- Sodium stearate soap ( C17H35COONa)
It is the sodium salt of long chain saturated fatty acid called stearic acid
Sodium Oleate soap (C17H33COONa)
It is the sodium salt of long chain unsaturated fatty acid called oleic acid.
Sodium palmitate soap (C15H31COONa)
It is the sodium salt of long chain saturated fatty acid called palmetic acid.
Soap is the salt of strong base NaOH and weak acid. So a soap solution is basic in
nature and turns red litmus to blue.
Soap is manufactured by heating animal fat or vegetable oil with concentrated NaOH
solution. The fats or oils react with NaOH to form soap and alcohol.
Fat/Vegetable oil + NaOH
Heat


Soap + Alcohol
The process of making soap by the hydrolysis of fats and oils with alkali is called
saponification.
Structure of a soap molecule:
A soap molecule is made up of two parts
1. A long chain hydrocarbon
2.
A short ionic part containing - COO -Na+
For simplicity soaps and detergents may be represented as above. The soap molecule
is said to have tad pole structure.
The long hydrocarbon chain is hydrophobic (water repellent). So the hydrocarbon part
of soap molecule is insolvent in water but soluble in oil and grease.
The ionic portion of soap molecule is hydrophilic (water attractant). So the ionic portion
of soap molecule is soluble in water.
Cleansing action of soap:
The dirt in the cloth is oily in nature. When the dirty cloth is dipped in soap or detergent
solution, the soap and dirt particles come in contact with each other.
The non-polar tails of soap begin to dissolve in non-polar oil and grease while the ionic
end of soap remains directed in water .
The soap molecules thus form structures called micelles where one end of the soap
molecule is towards the oil droplet while the ionic end faces outside. As more and more
soap molecules enter the grease each fat or oil particle is surrounded by a number of
negatively charged ends. Since the like charges repel each other the oil or grease
droplets break off into small globules of oil . These are still surrounded by the negatively
charged polar heads of the soap molecule. This prevents the small globules from
coming together to form bigger particles.
The rubbing by hand or mechanical stirring also helps to break the grease particles.
In this manner the grease particles can completely broken up and it forms emulsion of
grease or oil contained in dirt. As a result the cloth gets free from dirt and droplets are
washed away with water.
Limitations of Soap :
1. Soap is not suitable for washing clothes with hard water because of the following
Reasons:
i.
Hard water contains salts of Ca & Mg. When soap is added to hard water, Ca
and Mg ions of hard water react with soap forming insoluble calcium and
magnesium slats of fatty acids.
2C17H35COONa + MgCl2  (C17H35COO)2Mg + 2NaCl
2C17H35COONa + CaCl2  (C17H35COO)2Ca + 2NaCl
ii.
When hard water is used soap forms insoluble precipitates of Ca, Mg salts
which sticks to the cloth being washed. Therefore it interferes with the
cleaning ability of the soap and makes the cleaning process difficult.
Detergents :
Detergents are also called soap less soaps because they do not contain usual soap like
sodium stearate etc.,
Detergents are better cleaning agents than soaps because they do not form insoluble
Ca & Mg salts with hard water and hence can be used.
It is not possible to check whether a sample of water is hard by using detergent
because a detergent gives a lather easily in hard water.
A detergent is a sodium salt of long chain benzene sulphonic acid.
Or
Sodium salt of long chain alkyl hydrogen sulphate, which have cleansing properties in
water
O
|
–
CH3(CH2)11 - C6H4 - S – O Na +
|
O
(Sodium n – dodecyl Benzene sulphonate)
CH3 – (CH2)10 – CH2 – So4 – Na +
(sodium n do decyl sulphate)
Soap
1. Soaps are Na or K salts of long
chain fatty acids,
The ionic groups in the soap is –COONa+
Detergent
1. detergents are Na salts of long
Chain benzene sulphnate or alkyl
sulphonate
The ionic group is –SO3 – Na + or
–SO3– Na +
2. They cannot be used in acidic
solution
2. They can be used in acidic solution
3. They cannot be used in hard water
as they produce precipitate with Ca2+
and Mg2+ ions
3. They can be used even in hard
water as they do not form precipitate
with Ca2+ or Mg2+ ions
4. Soaps are biodegradable. So they
do not cause any pollution.
4. some of the detergents are not
biodegradable they pollute reiver and
lake water.
Disadvantages of detergents over soaps:
1. Some of the detergents which are made from large chain hydrocarbons having a
lot of branched chains are not biodegradable i.e they cannot be decomposed by
micro bacteria and thus cause pollution in rivers and lakes.
To solve this problem, now a days the detergents are prepared from
hydrocarbons having minimum branching. These are degraded more easily than
branched chain detergents.
Advantages of detergents over soap:
1. Synthetic detergents can be used for washing even in hard water whereas soaps are
not suitable to use with hard water.
2. Synthetic detergents can be used even in acidic solution because they do not
decompose in acidic solution. On the other hand soaps cannot be used in acidic
medium because they are decomposed into the carboxylic acid.
3. Synthetic detergents are more soluble in water than soaps.
4. Synthetic detergents have a strong cleansing action than soaps
Name the following compound
CH3
|
1. CH3 – C – CH3
2,2 dimethyl alkyl butane
|
C2H6
CH3
|
2. CH3 – CH = CH – C – CH3
|
CH3
Write the structural formula of the following
1.
2.
3.
4.
5.
6.
2 methyl 2 butane
2methyl propene
CH3CH2-COOH  Propanoic acid
CH3CHO  ethanol
CH3CH2CH2OH  Propanol
CH3 – CH – CH3  2Chloro propane
|
Cl
7.
CH3 CH – CH3
|
OH
8.
Butanoic acid
9.
Methanol
10
CH3- C – CH3
|
CH2
 propane- 2- ol
 2 Methyl propene
11 2,2 – dimethyl propane (neo pentane)
12 Cyclo propane
1. A compound has molecular formula C3H6. One mole of X reacts with one mole of
bromine to yield a compound Y. Deduce structures of X and Y
2. Define Isomerism. Wirte down the structures and names of isomers of butane
3. Which of the following belongs to same homologous series. Why?
C3H8, C3H6, C4H8, C4H6
4. Which of the following compounds would give addition reaction /
i. C2H6, ii. C3H8 , iii C3H6, iv. C2H2,
V CH4,
vi C3H4
5. What happens when vetable oil is hydrogenated? Explain with equation.
6. Write down the structure of
i. Ethanoic acid
ii. Butanol
7. What happens when a mixture of sodium ethonate and soda lime is heated
8. Give the names of the following functional groups
CHO
CO
OH
COOH
9. Write chemical equations for reaction of ethanoic acit with
i. Na2CO3
ii. K
iii soda lime
iv Ehanol in presence of Con.H2SO4
10. An organic compound ‘A’ of molecular formula C2H6O, on oxidation gives an acid
B with same number of carbon atoms in the molecule as A. Compound A is often used
for sterlisation of skin by doctors. Name the compound A and B. Write the chemical
equation.
11. What is meant by functional group in an organic compound ?
12 Give the structural formula of the functional groups in
i. Acetic acid
ii. Ethyl alcohol
13. Write the molecular formula of ethanol and propionic acid (common name of
propanoic aci)
H H H
|
|
|
14. The structural formula of an ester is H – C – O – C – C – C - H
||
| |
|
O
H H H
Of acid and alcohol from which it is formed
Acid
Alcohol
15. An organic compound A has formula C2H4O2 reacts with Na metal and evolves a
gas B which readily catches fire. ‘A’ also reacts with ethanol in the presecnce of Con.
H2SO4 to form sweet smelling substance used in perfumes.
i. Identify A,B,C.
ii. Write balanced chemical equation to represent the conversion of A into C
16. Distinguish between addition and substitution
17. Compare the following properties of ethanol and ethanoic acid
I. Litmus test
ii. Sodium bicarbonate test
iii. Na metal test
18. An organic compound A is widely used as preservatives inpickle and has a formula
C2H4O2. The compound reacts with ethanol to form a sweet smelling compound B
i. Identify A
ii. Write the chemical equation
iii. How can we get compound A from B
iv. which gas is produced when compound A reacts with washing soda.
19. Why does carbon form largest number of compounds
20. why are some of these called saturated and the other unsaturated
21. Which of these two are more reactive
22. Write the name of the compound
i. CH3CH2Br
ii.
H H H
|
|
|
C–C–C– C
| |
|
H H H

C – H  pentyne
23. An organic compound burns with soothy yellow flame. It is saturated or unsaturated
24. Two carbon compound A and B have C3H8 and C3H6 respectively as their
molecular formula. Which one of tw is most likely to show addition reaction. Justify your
answer
25. Explain with the help of chemical equation how addition reaction is useful in
vegetable ghee industry/
26. Why does carbon form compound mainly by covalent bonding ?
27 List any two reasons for carbon forming a very large No. of compounds.
28,. An organic compound X is a liquid which often freezes during winter in cold
county’s having formula C2H4O2. On warming with ethanol in presence of few drops of
con. H2SO4 a compound Y with sweet smell is formed. Identify X and Y