1. Alkanes & Alkenes Definition & Naming Heuristics (Mnemonics)
Physical & Chemical
Properties
General & Structural
Formula

2. Definition of HOMOLOGOUS SERIES
A group of organic compounds
with the SAME general formula,
in which one member differ from the next
by a –CH2 group.

3. Heuristics Mummy Eats Peanut Butter Pancake Happily 1 Met- 2 Eth- 3
No. of carbon atoms
Mnemonic
Chemical
Formula 1
Mummy
Met- 2
Eats
Eth- 3
Peanut
Prop- 4
Butter
But- 5
Pancake
Pent- 6
Happily
Hex-

4. Diagrammatic representation
Mummy
Eats
Peanut
Butter
Pancake
Happily

5. when drawing structural formula,
Guiding principles
when drawing structural formula,
Symbol
Name of element
Number of lines H
Hydrogen 1 O
Oxygen 2 N
Nitrogen 3 C
Carbon 4

6. CH4 C2H6 C3H8 Naming of Alkanes General Formula : CnH2n+2 H H-C-H H H
No. of carbon atoms
Name
Chemical
Formula
Structural H
H-C-H
H H
H-C-C-H
H H H
H-C-C-C-H
CH4 1
Methane
C2H6 2
Ethane
C3H8 3
Propane

7. C4H10 C5H12 C6H14 Naming of Alkanes H H H H H-C-C-C-C-H H H H H H
No. of carbon atoms
Name
Chemical
Formula
Structural
H H H H
H-C-C-C-C-H
H H H H H
H-C-C-C-C-C-H
H H H H H H
H-C-C-C-C-C-C-H
C4H10 4
Butane
C5H12 5
Pentane 6
C6H14
Hexane

8. C2H4 C3H6 Naming of Alkenes General Formula : CnH2n H H H-C=C-H 1
No. of carbon atoms
Name
Chemical
Formula
Structural -
H H
H-C=C-H
H H H
H-C=C-C-H H 1
C2H4 2
Ethene
C3H6 3
Propene

9. C4H8 C5H10 C6H12 Naming of Alkenes H H H H H-C=C-C-C-H H H H H H H H
No. of carbon atoms
Name
Chemical
Formula
Structural
H H H H
H-C=C-C-C-H
H H
H H H H H
H-C=C-C-C-C-H
H H H
H H H H H H
H-C=C-C-C-C-C-H
H H H H
C4H8 4
Butane
C5H10 5
Pentane 6
C6H12
Hexane

10. Physical Properties for straight-chain alkanes
Boiling pt as the number of carbon atoms .
Boiling point
Number of carbon atoms

11. Chemical Properties for straight-chain alkanes
Generally unreactive except with oxygen.
Alkane + oxygen carbon dioxide + water
C2H O CO H2O

12. Chemical Properties for straight-chain alkenes
Reaction with oxygen.
Alkene + oxygen carbon dioxide + water
C2H O CO H2O
Reaction with hydrogen.
Alkene + hydrogen Alkane
C2H H C2H6

13. Chemical Properties for straight-chain alkenes
Reaction with steam.
Alkene + steam Alcohol
C2H H2O C2H5OH
Phosphoric (V) acid
catalyst
Reaction with bromine.
Alkene + bromine ,2-dibromoalkane
C2H Br C2H4Br2
colourless
orange-red