Chapter 12 - Organic Chemistry- Some Basic Principles And Techniques, chemistry - Class 11 PDF Download

 Page 1


147 
 
CHAPTER 12 
Organic chemistry : Some Basic Principles and Techniques 
Organic compounds are the hydrocarbons and their derivatives and organic 
chemistry is that branch of chemistry that deals with the study of these compounds 
Tetravalency of carbon 
The atomic number of Carbon is 6 and its electronic configuration is 2,4 i.e. it has 4 
valence electrons. Thus carbon is always tetracovalent, i.e. it forms 4 covalent 
bonds with other atoms  
     C 
 
Due to tetravalency of carbon it has a tetrahedron shape. 
Catenation- The self linking property of carbon is known as catenation. This is the 
main reason of existence of such large number of compounds 
Classification of organic compounds 
                                         Organic compounds 
                      Acyclic                                                                Cyclic 
Homocyclic                             heterocyclic 
                                              Alicyclic                                  aromatic 
Benzenoid                    non benzenoid 
Functional groups:A functional group may be defined as an atom or a group of 
atoms present in a molecule which largely determines the chemical properties.  
CLASS OF ORGANIC        NAME OF FUNCTIONAL                  STRUCTURE 
COMPOUNDS                            GROUP                                                              
Alkenes                                       double bond    =C=C= 
Alkynes                                       triple bond       - C ? C - 
Halogens                                     halogen      - X ( F,Cl,Br,I ) 
Alcohols                                       hydroxyl     -OH 
Aldehydes                                   aldehydic(formyl)    -CHO 
Carboxylic acids                           carboxyl     -COOH 
Acid amides                                  amides     -CONH
2
 
Primary amines                             amino     - NH
2
 
Page 2


147 
 
CHAPTER 12 
Organic chemistry : Some Basic Principles and Techniques 
Organic compounds are the hydrocarbons and their derivatives and organic 
chemistry is that branch of chemistry that deals with the study of these compounds 
Tetravalency of carbon 
The atomic number of Carbon is 6 and its electronic configuration is 2,4 i.e. it has 4 
valence electrons. Thus carbon is always tetracovalent, i.e. it forms 4 covalent 
bonds with other atoms  
     C 
 
Due to tetravalency of carbon it has a tetrahedron shape. 
Catenation- The self linking property of carbon is known as catenation. This is the 
main reason of existence of such large number of compounds 
Classification of organic compounds 
                                         Organic compounds 
                      Acyclic                                                                Cyclic 
Homocyclic                             heterocyclic 
                                              Alicyclic                                  aromatic 
Benzenoid                    non benzenoid 
Functional groups:A functional group may be defined as an atom or a group of 
atoms present in a molecule which largely determines the chemical properties.  
CLASS OF ORGANIC        NAME OF FUNCTIONAL                  STRUCTURE 
COMPOUNDS                            GROUP                                                              
Alkenes                                       double bond    =C=C= 
Alkynes                                       triple bond       - C ? C - 
Halogens                                     halogen      - X ( F,Cl,Br,I ) 
Alcohols                                       hydroxyl     -OH 
Aldehydes                                   aldehydic(formyl)    -CHO 
Carboxylic acids                           carboxyl     -COOH 
Acid amides                                  amides     -CONH
2
 
Primary amines                             amino     - NH
2
 
148 
 
HOMOLOGOUS SERIES 
Homologous series is defined as a family or group of structurally similar organic 
compounds all members of which contain the same functional group, show a 
gradation in physical and similarity in chemical properties and any two adjacent 
members of which differ by  -CH
2
 group. The individual members of this group are 
called homologues and the phenomenon is called homology. 
NOMENCLATURE OF ORGANIC COMPOUNDS 
Organic chemistry deals with millions of compounds. In order to clearly identify 
them, a systematic method of naming known as IUPAC system of nomenclature is 
adopted. The names are such that the listener can deduce the structure from it. The 
IUPAC name  consists of three parts: 
                          Prefix                  Word root              Suffix 
     EX:               3 methlyoctane 
NOMENCLATURE OF ALKANES 
Straight chain alkanes: 
The names of such compounds is based on their chain structure,and end with suffix  
‘-ane’ and carry a prefix indicating the number of carbon atoms present in the chain. 
Branched chain hydrocarbons: 
1.) The longest carbon chain in the molecule is identified. 
2.) The numbering is done in such a way that the branched carbon atoms get the 
lowest possible value. 
3.) The names of the alkyl groups attached as a branch are then prefixed to the 
name of the parent alkane and its position is indicated by numbers. 
4.) The lower number is given to the first in alphabetical order. 
5.) The carbon atom of the branch that attaches to the root alkane is numbered 1.  
Organic compounds having Functional Groups: 
   The longest chain of carbon atoms containing the functional groups is numbered in 
such a way that the functional group attached to the carbon atom gets the lowest 
possible number in the chain. 
When there are more functional groups then a priority order is followed as: 
-COOH, -SO
3
H, -COOR, COCl, -CONH
2
, -CN, -HC=O, =C=O, -OH, -NH
2
, =C=C=,   
-C?  C-. 
ISOMERISM 
Two or more compounds having the same molecular formula but different  physical 
and chemical properties are called isomers and this phenomenon is called isomerism. 
Page 3


147 
 
CHAPTER 12 
Organic chemistry : Some Basic Principles and Techniques 
Organic compounds are the hydrocarbons and their derivatives and organic 
chemistry is that branch of chemistry that deals with the study of these compounds 
Tetravalency of carbon 
The atomic number of Carbon is 6 and its electronic configuration is 2,4 i.e. it has 4 
valence electrons. Thus carbon is always tetracovalent, i.e. it forms 4 covalent 
bonds with other atoms  
     C 
 
Due to tetravalency of carbon it has a tetrahedron shape. 
Catenation- The self linking property of carbon is known as catenation. This is the 
main reason of existence of such large number of compounds 
Classification of organic compounds 
                                         Organic compounds 
                      Acyclic                                                                Cyclic 
Homocyclic                             heterocyclic 
                                              Alicyclic                                  aromatic 
Benzenoid                    non benzenoid 
Functional groups:A functional group may be defined as an atom or a group of 
atoms present in a molecule which largely determines the chemical properties.  
CLASS OF ORGANIC        NAME OF FUNCTIONAL                  STRUCTURE 
COMPOUNDS                            GROUP                                                              
Alkenes                                       double bond    =C=C= 
Alkynes                                       triple bond       - C ? C - 
Halogens                                     halogen      - X ( F,Cl,Br,I ) 
Alcohols                                       hydroxyl     -OH 
Aldehydes                                   aldehydic(formyl)    -CHO 
Carboxylic acids                           carboxyl     -COOH 
Acid amides                                  amides     -CONH
2
 
Primary amines                             amino     - NH
2
 
148 
 
HOMOLOGOUS SERIES 
Homologous series is defined as a family or group of structurally similar organic 
compounds all members of which contain the same functional group, show a 
gradation in physical and similarity in chemical properties and any two adjacent 
members of which differ by  -CH
2
 group. The individual members of this group are 
called homologues and the phenomenon is called homology. 
NOMENCLATURE OF ORGANIC COMPOUNDS 
Organic chemistry deals with millions of compounds. In order to clearly identify 
them, a systematic method of naming known as IUPAC system of nomenclature is 
adopted. The names are such that the listener can deduce the structure from it. The 
IUPAC name  consists of three parts: 
                          Prefix                  Word root              Suffix 
     EX:               3 methlyoctane 
NOMENCLATURE OF ALKANES 
Straight chain alkanes: 
The names of such compounds is based on their chain structure,and end with suffix  
‘-ane’ and carry a prefix indicating the number of carbon atoms present in the chain. 
Branched chain hydrocarbons: 
1.) The longest carbon chain in the molecule is identified. 
2.) The numbering is done in such a way that the branched carbon atoms get the 
lowest possible value. 
3.) The names of the alkyl groups attached as a branch are then prefixed to the 
name of the parent alkane and its position is indicated by numbers. 
4.) The lower number is given to the first in alphabetical order. 
5.) The carbon atom of the branch that attaches to the root alkane is numbered 1.  
Organic compounds having Functional Groups: 
   The longest chain of carbon atoms containing the functional groups is numbered in 
such a way that the functional group attached to the carbon atom gets the lowest 
possible number in the chain. 
When there are more functional groups then a priority order is followed as: 
-COOH, -SO
3
H, -COOR, COCl, -CONH
2
, -CN, -HC=O, =C=O, -OH, -NH
2
, =C=C=,   
-C?  C-. 
ISOMERISM 
Two or more compounds having the same molecular formula but different  physical 
and chemical properties are called isomers and this phenomenon is called isomerism. 
149 
 
Chain isomerism: When two or more compounds having same molecular formula 
but different carbon skeletons are referred to as chain isomers. 
   
Position Isomerism : Compounds which have the same structure of carbon chain but 
differ in position of double or triple bonds or functional group are called position 
isomers and this phenomenon is called Position Isomerism. e  g 
CH
3
-CH
2
-CH=CH
2
  CH
3
-CH = CH – CH
3
 
Functional Isomerism :Compounds which have the same molecular formula but 
different  functional group are called functional isomers and this phenomenon is 
called functional Isomerism. e  g 
CH
3
 – CH
2
 – OH  CH
3
 – O – CH
3 
Metamerism:It  is due to the presence of different alkyl groups on either side of 
functional group in the molecule. Ex.  C
4
H
10
O represents C
2
H
5
OC
2
H
5
  and 
CH
3
OC
3
H
7
. 
FISSION OF COVALENT BOND 
Heterolytic cleavage: In this cleavage the bond breaks in such a way that the shared 
pair of electron remains with one of the fragments. 
H
3
C – Br  
+
CH
3
  + Br
- 
Homolytic Cleavage: In this cleavage the shared pair of electron goes with each of 
the bonded atom. 
R – X   R
.
  + X
. 
  Alkyl free radical 
Nucleophiles : A reagent that brings an electron pair is called nucleophile  ie nucleus 
seeking e g -OH , -CN  
Electrophiles: A reagent that takes away electron pair is called electrophile I e 
electron seeking e g > C= O , R
3
C – X 
Inductive Effect: The displacement of the electron along the chain of the carbon 
atoms due to presence of an atom or group  at the end of the chain. 
Page 4


147 
 
CHAPTER 12 
Organic chemistry : Some Basic Principles and Techniques 
Organic compounds are the hydrocarbons and their derivatives and organic 
chemistry is that branch of chemistry that deals with the study of these compounds 
Tetravalency of carbon 
The atomic number of Carbon is 6 and its electronic configuration is 2,4 i.e. it has 4 
valence electrons. Thus carbon is always tetracovalent, i.e. it forms 4 covalent 
bonds with other atoms  
     C 
 
Due to tetravalency of carbon it has a tetrahedron shape. 
Catenation- The self linking property of carbon is known as catenation. This is the 
main reason of existence of such large number of compounds 
Classification of organic compounds 
                                         Organic compounds 
                      Acyclic                                                                Cyclic 
Homocyclic                             heterocyclic 
                                              Alicyclic                                  aromatic 
Benzenoid                    non benzenoid 
Functional groups:A functional group may be defined as an atom or a group of 
atoms present in a molecule which largely determines the chemical properties.  
CLASS OF ORGANIC        NAME OF FUNCTIONAL                  STRUCTURE 
COMPOUNDS                            GROUP                                                              
Alkenes                                       double bond    =C=C= 
Alkynes                                       triple bond       - C ? C - 
Halogens                                     halogen      - X ( F,Cl,Br,I ) 
Alcohols                                       hydroxyl     -OH 
Aldehydes                                   aldehydic(formyl)    -CHO 
Carboxylic acids                           carboxyl     -COOH 
Acid amides                                  amides     -CONH
2
 
Primary amines                             amino     - NH
2
 
148 
 
HOMOLOGOUS SERIES 
Homologous series is defined as a family or group of structurally similar organic 
compounds all members of which contain the same functional group, show a 
gradation in physical and similarity in chemical properties and any two adjacent 
members of which differ by  -CH
2
 group. The individual members of this group are 
called homologues and the phenomenon is called homology. 
NOMENCLATURE OF ORGANIC COMPOUNDS 
Organic chemistry deals with millions of compounds. In order to clearly identify 
them, a systematic method of naming known as IUPAC system of nomenclature is 
adopted. The names are such that the listener can deduce the structure from it. The 
IUPAC name  consists of three parts: 
                          Prefix                  Word root              Suffix 
     EX:               3 methlyoctane 
NOMENCLATURE OF ALKANES 
Straight chain alkanes: 
The names of such compounds is based on their chain structure,and end with suffix  
‘-ane’ and carry a prefix indicating the number of carbon atoms present in the chain. 
Branched chain hydrocarbons: 
1.) The longest carbon chain in the molecule is identified. 
2.) The numbering is done in such a way that the branched carbon atoms get the 
lowest possible value. 
3.) The names of the alkyl groups attached as a branch are then prefixed to the 
name of the parent alkane and its position is indicated by numbers. 
4.) The lower number is given to the first in alphabetical order. 
5.) The carbon atom of the branch that attaches to the root alkane is numbered 1.  
Organic compounds having Functional Groups: 
   The longest chain of carbon atoms containing the functional groups is numbered in 
such a way that the functional group attached to the carbon atom gets the lowest 
possible number in the chain. 
When there are more functional groups then a priority order is followed as: 
-COOH, -SO
3
H, -COOR, COCl, -CONH
2
, -CN, -HC=O, =C=O, -OH, -NH
2
, =C=C=,   
-C?  C-. 
ISOMERISM 
Two or more compounds having the same molecular formula but different  physical 
and chemical properties are called isomers and this phenomenon is called isomerism. 
149 
 
Chain isomerism: When two or more compounds having same molecular formula 
but different carbon skeletons are referred to as chain isomers. 
   
Position Isomerism : Compounds which have the same structure of carbon chain but 
differ in position of double or triple bonds or functional group are called position 
isomers and this phenomenon is called Position Isomerism. e  g 
CH
3
-CH
2
-CH=CH
2
  CH
3
-CH = CH – CH
3
 
Functional Isomerism :Compounds which have the same molecular formula but 
different  functional group are called functional isomers and this phenomenon is 
called functional Isomerism. e  g 
CH
3
 – CH
2
 – OH  CH
3
 – O – CH
3 
Metamerism:It  is due to the presence of different alkyl groups on either side of 
functional group in the molecule. Ex.  C
4
H
10
O represents C
2
H
5
OC
2
H
5
  and 
CH
3
OC
3
H
7
. 
FISSION OF COVALENT BOND 
Heterolytic cleavage: In this cleavage the bond breaks in such a way that the shared 
pair of electron remains with one of the fragments. 
H
3
C – Br  
+
CH
3
  + Br
- 
Homolytic Cleavage: In this cleavage the shared pair of electron goes with each of 
the bonded atom. 
R – X   R
.
  + X
. 
  Alkyl free radical 
Nucleophiles : A reagent that brings an electron pair is called nucleophile  ie nucleus 
seeking e g -OH , -CN  
Electrophiles: A reagent that takes away electron pair is called electrophile I e 
electron seeking e g > C= O , R
3
C – X 
Inductive Effect: The displacement of the electron along the chain of the carbon 
atoms due to presence of an atom or group  at the end of the chain. 
150 
 
?+++ ? ++ ?+ 
CH
3
-         C H
2    
      CH
2           
Cl 
Resonance Effect : The polarity produced in the molecule by the interaction of two 
pi bonds or between a pi bond and lone pair of electron present on an adjacent atom. 
There are two types of resonance effect: 
1) Positive resonance effect : In this effect the transfer of electrons is away from 
an atom or substituent group attached to the conjugated system. 
 The atoms or groups which shows +R effect are halogens,-OH , -OR,-
NH
2
 
2)  Negative resonance effect : In this effect the transfer of electrons is towards 
the  atom or substituent group attached to the conjugated system. 
 The atoms or groups which shows -R effect are –COOH , -CHO , -CN  
METHODS OF PURIFICATION OF ORGANIC COMPOUNDS : 
Sublimation : This method is used to separate the sublimable compounds from non 
sublimable compounds. 
Crystallisation: This method is based on the difference in the solubilities of 
compound and impurities in a suitable solvent. The impure compound is dissolved in 
solvent at heated at higher temp .on cooling the hot and conc solution pure 
compounds crystallizes out. 
Distillation: This method is used to separate volatile liquids from non volatile liquids 
and liquids having sufficient difference in their boiling points. 
Fractional distillation: If the boiling points of two liquids is not much , they are 
separated by this method. 
Distillation under reduced pressure : This method is used to purify liquids having 
high boiling points  and decomposes at or below their boiling points. 
Steam distillation : This method is used to separate substances which are steam 
volatile and are immiscible with water. 
Differential Extraction: When an organic compound is present in an aqueous 
medium it is separated by shaking it with organic solvent in which it is more soluble 
than in water. The aqueous solution is mixed with organic solvent in a separating 
funnel and shaken for sometimes and then allowed to stand for some time .when 
organic solvent and water form two separate layers the lower layer is run out by 
opening the tap of funnel and organic layer is separated. the process is repeated 
several times and pure organic compound is separated. 
Chromatography :This technique is used to separate mixtures in to their 
components ,purify the compounds and test the purity of compounds.It is classified 
as  
Page 5


147 
 
CHAPTER 12 
Organic chemistry : Some Basic Principles and Techniques 
Organic compounds are the hydrocarbons and their derivatives and organic 
chemistry is that branch of chemistry that deals with the study of these compounds 
Tetravalency of carbon 
The atomic number of Carbon is 6 and its electronic configuration is 2,4 i.e. it has 4 
valence electrons. Thus carbon is always tetracovalent, i.e. it forms 4 covalent 
bonds with other atoms  
     C 
 
Due to tetravalency of carbon it has a tetrahedron shape. 
Catenation- The self linking property of carbon is known as catenation. This is the 
main reason of existence of such large number of compounds 
Classification of organic compounds 
                                         Organic compounds 
                      Acyclic                                                                Cyclic 
Homocyclic                             heterocyclic 
                                              Alicyclic                                  aromatic 
Benzenoid                    non benzenoid 
Functional groups:A functional group may be defined as an atom or a group of 
atoms present in a molecule which largely determines the chemical properties.  
CLASS OF ORGANIC        NAME OF FUNCTIONAL                  STRUCTURE 
COMPOUNDS                            GROUP                                                              
Alkenes                                       double bond    =C=C= 
Alkynes                                       triple bond       - C ? C - 
Halogens                                     halogen      - X ( F,Cl,Br,I ) 
Alcohols                                       hydroxyl     -OH 
Aldehydes                                   aldehydic(formyl)    -CHO 
Carboxylic acids                           carboxyl     -COOH 
Acid amides                                  amides     -CONH
2
 
Primary amines                             amino     - NH
2
 
148 
 
HOMOLOGOUS SERIES 
Homologous series is defined as a family or group of structurally similar organic 
compounds all members of which contain the same functional group, show a 
gradation in physical and similarity in chemical properties and any two adjacent 
members of which differ by  -CH
2
 group. The individual members of this group are 
called homologues and the phenomenon is called homology. 
NOMENCLATURE OF ORGANIC COMPOUNDS 
Organic chemistry deals with millions of compounds. In order to clearly identify 
them, a systematic method of naming known as IUPAC system of nomenclature is 
adopted. The names are such that the listener can deduce the structure from it. The 
IUPAC name  consists of three parts: 
                          Prefix                  Word root              Suffix 
     EX:               3 methlyoctane 
NOMENCLATURE OF ALKANES 
Straight chain alkanes: 
The names of such compounds is based on their chain structure,and end with suffix  
‘-ane’ and carry a prefix indicating the number of carbon atoms present in the chain. 
Branched chain hydrocarbons: 
1.) The longest carbon chain in the molecule is identified. 
2.) The numbering is done in such a way that the branched carbon atoms get the 
lowest possible value. 
3.) The names of the alkyl groups attached as a branch are then prefixed to the 
name of the parent alkane and its position is indicated by numbers. 
4.) The lower number is given to the first in alphabetical order. 
5.) The carbon atom of the branch that attaches to the root alkane is numbered 1.  
Organic compounds having Functional Groups: 
   The longest chain of carbon atoms containing the functional groups is numbered in 
such a way that the functional group attached to the carbon atom gets the lowest 
possible number in the chain. 
When there are more functional groups then a priority order is followed as: 
-COOH, -SO
3
H, -COOR, COCl, -CONH
2
, -CN, -HC=O, =C=O, -OH, -NH
2
, =C=C=,   
-C?  C-. 
ISOMERISM 
Two or more compounds having the same molecular formula but different  physical 
and chemical properties are called isomers and this phenomenon is called isomerism. 
149 
 
Chain isomerism: When two or more compounds having same molecular formula 
but different carbon skeletons are referred to as chain isomers. 
   
Position Isomerism : Compounds which have the same structure of carbon chain but 
differ in position of double or triple bonds or functional group are called position 
isomers and this phenomenon is called Position Isomerism. e  g 
CH
3
-CH
2
-CH=CH
2
  CH
3
-CH = CH – CH
3
 
Functional Isomerism :Compounds which have the same molecular formula but 
different  functional group are called functional isomers and this phenomenon is 
called functional Isomerism. e  g 
CH
3
 – CH
2
 – OH  CH
3
 – O – CH
3 
Metamerism:It  is due to the presence of different alkyl groups on either side of 
functional group in the molecule. Ex.  C
4
H
10
O represents C
2
H
5
OC
2
H
5
  and 
CH
3
OC
3
H
7
. 
FISSION OF COVALENT BOND 
Heterolytic cleavage: In this cleavage the bond breaks in such a way that the shared 
pair of electron remains with one of the fragments. 
H
3
C – Br  
+
CH
3
  + Br
- 
Homolytic Cleavage: In this cleavage the shared pair of electron goes with each of 
the bonded atom. 
R – X   R
.
  + X
. 
  Alkyl free radical 
Nucleophiles : A reagent that brings an electron pair is called nucleophile  ie nucleus 
seeking e g -OH , -CN  
Electrophiles: A reagent that takes away electron pair is called electrophile I e 
electron seeking e g > C= O , R
3
C – X 
Inductive Effect: The displacement of the electron along the chain of the carbon 
atoms due to presence of an atom or group  at the end of the chain. 
150 
 
?+++ ? ++ ?+ 
CH
3
-         C H
2    
      CH
2           
Cl 
Resonance Effect : The polarity produced in the molecule by the interaction of two 
pi bonds or between a pi bond and lone pair of electron present on an adjacent atom. 
There are two types of resonance effect: 
1) Positive resonance effect : In this effect the transfer of electrons is away from 
an atom or substituent group attached to the conjugated system. 
 The atoms or groups which shows +R effect are halogens,-OH , -OR,-
NH
2
 
2)  Negative resonance effect : In this effect the transfer of electrons is towards 
the  atom or substituent group attached to the conjugated system. 
 The atoms or groups which shows -R effect are –COOH , -CHO , -CN  
METHODS OF PURIFICATION OF ORGANIC COMPOUNDS : 
Sublimation : This method is used to separate the sublimable compounds from non 
sublimable compounds. 
Crystallisation: This method is based on the difference in the solubilities of 
compound and impurities in a suitable solvent. The impure compound is dissolved in 
solvent at heated at higher temp .on cooling the hot and conc solution pure 
compounds crystallizes out. 
Distillation: This method is used to separate volatile liquids from non volatile liquids 
and liquids having sufficient difference in their boiling points. 
Fractional distillation: If the boiling points of two liquids is not much , they are 
separated by this method. 
Distillation under reduced pressure : This method is used to purify liquids having 
high boiling points  and decomposes at or below their boiling points. 
Steam distillation : This method is used to separate substances which are steam 
volatile and are immiscible with water. 
Differential Extraction: When an organic compound is present in an aqueous 
medium it is separated by shaking it with organic solvent in which it is more soluble 
than in water. The aqueous solution is mixed with organic solvent in a separating 
funnel and shaken for sometimes and then allowed to stand for some time .when 
organic solvent and water form two separate layers the lower layer is run out by 
opening the tap of funnel and organic layer is separated. the process is repeated 
several times and pure organic compound is separated. 
Chromatography :This technique is used to separate mixtures in to their 
components ,purify the compounds and test the purity of compounds.It is classified 
as  
151 
 
Adsorption Chromatography : It is based on the fact that different compounds are 
adsorbed on an adsorbent to different degrees. Silica jel or alumina is used as 
adsorbents. 
Partition Chromatography : It is based on the continuous differential portioning of 
components of a mixture between stationary and mobile phase. 
QUALITATIVE ANALYSIS OF ORGANIC COMPOUNDS  
Detection of Carbon and Hydrogen: The Carbon and Hydrogen present in the 
Organic compound  is detected by heating the compound with Copper II oxide in a 
hard glass tube when carbon present in the compound is oxidized to CO2 which can 
be tested with lime Water and Hydrogenis converted to water which can be tested 
with anhydrous copper sulphate which turns blue. 
C + CuO 2Cu  +  CO
2
 
2 H  +CuO Cu  +  H2O 
CO
2
  +Ca (OH )
2
 CaCO
3
  +  H
2
O 
5H
2
O  +  CuSO
4
 CuSO
4
.5H
2
O 
DETECTION OF OTHER ELEMENTS  
Sodium Fusion Extract: A small piece of dry Sodium metal is heated with a organic 
compound in a fusion tube for 2 -3 minutes and the red hot tube is plunged in to 
distilled water contained in a china dish. The contained of the china dish is boiled 
,cooled and filtered. The filtrate is known as Sodium fusion extract. 
Test for Nitrogen : The sodium fusion extract is boiled with iron II sulphate and 
then acidified with Concsulphuric acid , the formation of Prussian blue colour 
confirms the presence of nitrogen. 
6CN
-
 + Fe
2+
             [Fe(CN)
6
] 
4-
 
3[Fe(CN)
6
] 
4-
+ 4Fe
3+              xH
2
O 
               Fe
4
[Fe(CN)
6
] 
3
.xH
2
O 
Test for Sulphur: the sodium fusion extract is acidified with acetic acid and lead 
acetate is added to it. A black precipitate of lead sulphide indicates the presence of 
sulphur. S
2-
 + Pb
2+                              
PbS 
 Black 
Test for halogens:The sodium fusion extract is acidified with nitric acid and then 
treated with silver nitrate. A white precipitate, soluble in ammonium hydroxide 
shows the presence of chlorine, a yellowish ppt. sparingly soluble in  ammonium 
hydroxide shows the presence of bromine, a yellowish ppt. insoluble in ammonium 
hydroxide shows the presence of iodine. 
X
-
 + Ag
+                           
AgX