3. Carbon Compound
Organic Compound
-Carbon containing compounds
except oxides of carbon, carbonates,
syanides and metallic carbides
Hydrocarbon
-contain Carbon and
Hydrogen only
Alkanes
(saturated
hydrocarbons)
-contain only single
bond
Alkenes
(unsaturated
hydrocarbons)
-contain at least one
multiple bond
Non-hydrocarbon
-contain C,H and
O,N,P,S,F,Cl,Br,I
Alcohols
Carboxylic
acids
Esters
Inorganic Compound
-non-carbon
containing
compounds
4. Organic compound
Inorganic Carbon
compound
Similarity
Both contain carbon atoms
Diffenrences
Examples
Origin
Effect of heat
Solubility
Protein, fats, cellulose, natural
rubber, petroleum
Formed from living thing
Have low boiling points and
low melting point
Dissolve in organic solvents
such as ether, petrol, alcohol
and chloroform
Carbon dioxide, carbon
monoxide
Formed from minerals
Have high boiling points and
high melting point
Dissolve in inorganic solvents
such as ether, water, acids and
alkalis
5. Hydrocarbons
Hydrocarbons are organic compound that
contain only Carbon and Hydrogen
Natural sources of hydrocarbons:
• Petroleum
• Coal
• Natural gas
• Rubber trees
6. B: ALKANES
General Formula : CnH2n+2 , n=1,2,3…
Naming alkanes:
Number
of
Carbon
atoms
1 2 3 4 5 6 7 8 9 10
Root
name
Meth- Eth- Prop- But- Pent- Hex- Hept- Oct- Non- Dec-
Final
name
Methane Ethane Propane Butane Pentane Hexane Heptane Octane Nonane Decane
7. Structural Formula shows how the atoms in a
molecule are bonded together and by what types
of bonds
Example :
Ethane
C2H6
molecular formula structural formula
9. Chemical properties of alkanes
a) Combustion
1. Complete combustion
Alkanes burn in air to form carbon dioxide and water
CH4 (g) + 2O2(g) CO2 (g) + 2H2O(l)
More soot is given off when a higher alkane is burnt.
For example, the burning of heptane produce more
soot than the burning of ethane
2. Incomplete combustion
If insufficient oxygen available, carbon monoxide or even
carbon may be formed
2CH4 (g) + 3O2(g) 2CO (g) + 4H2O(l)
CH4 (g) + O2(g) C (s) + 2H2O(l)
10. b) Halogenation
-Reaction of alkanes with halogens.
-readily takes place in sunlight (not occur in the dark)
-carbon-hydrogen bonds are broken and new
carbon-halogens bonds are formed
-is a substitution reaction
occurs when one atom or a group of atoms in a
molecule is replaced by another atom or group of
atoms
11. -Example:
when a mixture of CH4 and chlorine is exposed to
ultraviolet light, 4 different products are formed
• CH4 (g) + Cl2(g) CH3Cl (g) + HCl(l)
Chloromethane hydrogen chloride
12.
13. C: ALKENES
is a hydrocarbons containing at least one carbon-carbon double
bond
General Formula : CnH2n , n=2,3,4…
Naming alkenes:
Number
of
Carbon
atoms
2 3 4 5 6 7 8 9 10
Root
name
Eth- Prop- But- Pent- Hex- Hept- Oct- Non- Dec-
Final
name
Ethene Propene But-1-ene Pent-1-ene Hex-1-ene Hept-1-ene Oct-1-ene Non-1-ene Dec-1-ene
17. Chemical properties of alkenes
a) Combustion reaction
Alkenes burn in excess oxygen to form carbon
dioxide and water
C2H4 (g) + 3O2(g) 2CO2 (g) + 2H2O(l)
Alkenes burn with sootier flames as compared to
alkanes because alkenes have a higher percentage
of carbon in their molecules than alkanes
19. (ii) Addition of halogens (halogenation)
Observation: reddish-brown bomine is decolourised
and colourless liquid is formed
This reaction is used as a test for the presence of
a carbon-carbon double bond in organic molecules
24. Homologous Series
A group or family of organic compounds that has the following
characteristics:
a) Members of the series can be represented by a general formula
b) Successive members differ from each other by –CH2
c) Members can be prepared by similar methods
d) Physical properties change regularly with increasing number of
carbon atoms
e) Members have similar chemical properties because they have the
same functional group
functional group :
-a special group of atoms attached to an organic mlecule
-determines the chemical properties of the molecule
-chemical reactions occur at the functional group
25. 5 homologous series learnt in this
chapter:
Homologous
series
General formula Functional Group
Alkane CnH2n+2 , n=1,2,3… Carbon-carbon single
bond, C-C
Alkene CnH2n , n=2,3,4… Carbon-carbon double
bond, C=C
Alcohol CnH2n+1OH ,n=1,2,3… Hydroxyl group, -OH
Carboxylic Acid CnH2n+1 COOH ,n=0,1,2,… Carboxyl group, -COOH
Ester CnH2n+1 COOCmH2m+1,
n=0,1,2,…
m=1,2,3…
Carboxylate group, -COO-
26. First member
Second member
Third member
…..
…..
…..
As the number of
carbon atoms per
molecule increases:
•Melting point
increases
•Boiling point increases
•Volatility decreases
•Density increases
Descending
homologous series
27. D: ISOMERISM
Isomerism is a phenomenon whereby 2 or more
molecules are found to have same molecular
formula but different structural formula
Isomers: molecules with the same molecular
formula but with different structural
formula
29. Steps to draw structural formula of isomers of
alkanes
Draw all the possible straight- chain and branched-chain carbon
skeletons
Place single bonds around every carbon atom. Ensure that each
carbon atom has 4 bonds
Place a hydrogen atom at each of the single bonds
30. Naming carboxylic acids
Find the longest continuous carbon chain containing the carboxyl
group
Name this longest chain by replacing the ending –e of the
corresponding alkane with –oic acid
Number the carbon atoms in this longest chain beginning at the
carboxyl group
Locate and name the attached alkyl group
Complete the name for the carboxylic acid molecule by combining
the 2 component parts together