Basic Organic Assignment

1. Basic Organic Chemistry
Nur Faralina Binti Asrab Ali D20101037415
Wan Norazwani Bt Mahusin D20101037533
Fatin Nasuha

2. HYDROCARBON
ALPHATIC
ALKANES
(saturated)
Contain only single bond
CYCLOALKANES (saturated)
Alkane which C atoms are join
in rings
ALKENES
(unsaturated)
Contain C=C
CYCLOALKENES
(unsaturated)
ALKYNES
(unsaturated)
Contain C=C
AROMATIC
(contain one or more
benzene ring)

3. ALKANES
• Alkanes are known as saturated hydrocarbon
which contain only single covalent bonds.
• General formula for straight chain of alkanes
is CnH2n+2 where n≥1
• Each carbon atom is alkanes is
sp3 hybridised
tetrahedral with four sigma bond (formed
by the four sp3 hybrid orbitals)
• Alkanes IUPAC names have the –ane suffix.

4. The First Ten Unbranched
Alkanes
Molecular
formula
Structural
formula
No. of C
atoms
Name
CH4 CH4 1 Methane
C2H6 CH3-CH3 2 Ethane
C3H8 CH3-CH2-CH3 3 Propane
C4H10 CH3-(CH2)2-CH3 4 Butane
C5H12 CH3-(CH2)3-CH3 5 Pentane
C6H14 CH3-(CH2)4-CH3 6 Hexane
C7H16 CH3-(CH2)5-CH3 7 Heptane
C8H18 CH3-(CH2)6-CH3 8 Octane
C9H20 CH3-(CH2)7-CH3 9 Nonane
C10H22 CH3-(CH2)8-CH3 10 Decane

5. • Starting from C4H10 onwards, the
alkanes show the phenomenon of chain
isomerism
• They can exist as linear or branched
alkanes.

6. Example
C4H10
CH3CH2CH2CH3 CH3CHCH3
CH3

7. IUPAC NOMENCLATURE
• IUPAC-International Union of Pure and
Applied Chemistry
• Branched-chain alkanes are named
according to the following rules:

8. STEP 1
• Choose the longest continuous chain of carbon
atoms; this chain determines the parent name
for alkanes.

9. STEP 2
• Number the longest chain beginning with the
end of the chain nearer the substituent.

10. STEP 3
• Use rule number 2 to locate the position of the
substituent.
• The position and the name of the substituent
must be written in front of the parent chain.

11. STEP 4
–If two or more substituent are
present, give each substituent a number
corresponding to its location on the longest
chain.
The substituent should be listed alphabetically
In alphabetizing, the prefixes di, tri, tetra, sec-, tert-
are ignored except iso and neo

12. STEP 5
• If two substituent are present on
the same carbon atom, use that
number twice.

13. STEP 6
• If two or more identical substituent are
present, use prefixes di-(two identical
substituent), tri-(three identical
substituent), tetra-(four identical
substituent).
• Commas are used to separate numbers
from each other.

14. STEP 7
• If there are two chains of equal
length as the parent chain, choose
the chain with the greater
number of substituent.

15. STEP 8
• If branching occurs at an equal distance
from either end of the longest
chain, choose the name that gives the
lower number at the first point of
difference.

16. Cycloalkanes
?

17. Introduction
Called as naphthenes
Types of alkanes that have one or more
rings of carbon atoms
Contain only carbon-carbon single bonds
and are saturated hydrocarbons.
General formula : CnH2n.
Has less hydrogen atom than alkanes
Drawn in simple polygons

18. Continue..
Each corner of polygon is a carbon atom attached
to two hydrogen atoms.
The single ring are named analogously to their
normal alkanes counterpart of the same carbon
count such as
Cyclopropane, Cyclobutane, Cyclopentane,

19. Multiple rings
Spiro cyclic
compounds
Fused rings
compounds
Bridged ring
compounds

20. Continue..
One carbon atom shared between two rings
known as spiro cyclic compounds. Fused ring
compounds shared two common atoms and
the bond between them. Bridged ring
compound shared two nonadjacent carbon
atoms.

21. Naming Cycloalkanes
 Cycloalkanes are named according to
the IUPAC system by using the prefix
cyclo-.
 There are only two steps:
1) Find the parent.
2)Number of substituent and write the
name.

22. Step 1:
Find the parent
Count the number of carbon atoms in the
ring and the number in the largest
substituent
If the number of carbon atoms in the
ring greater or equal to substituent, it is
called alkyl-substituent
If the number of carbon atom in the
largest substituent is greater than the
number in the ring, it named as a
cycloalkyl-substituted alkane.

23. Step 2:
Number of Substituent and
Write The Name
For alkyl or halo-substituent(i)
• If two or more substituents, choose a point of attachment as
carbon 1 such that the second substituent has a low number
as possible
For different alkyl(ii)
• Number them by alphabetical priority, ignoring numerical
prefixes such as di- and tri-.
For halogen(iii)
• Treat them just like alkyl groups.

24. PHYSICAL PROPERTIES OF ALKANES
• Different physical properties
of alkanes is resulting from
different range of molecular
weight( different of c )
• On this subtopic we will cover
about
 boiling point
Melting point
solubilty

25. Boiling Point
1) Increase smoothly with
increasing number of c
atoms(molecular
weight/molar mass)
•Greater number of C atom
•Large molecule
•Greater surface area
•Stronger Van Der Waals
attraction
•Higher boiling point

26. Example
CH3CH2 CH2 CH3 CH3 CH2 CH2 CH2 CH3 CH3 CH2 CH2 CH2 CH2 CH3
Butane Pentane Hexane
Bp=0° C Bp=36° C Bp=79° C
Increasing surface area
Increasing boiling point

27. Effect of Chain Branching
2) Branching of alkane
chain lowers boiling point
 More branches
Molecular shapebecomes
more compact
Surface area reduced
Weaker Van Der Waals
attraction
Lower boiling point

28. Example

29. Straight with Cycloalkane
• When compairing at the same number of
C, cycloalkanes has slightly higher boiling
point than alkanes.
Compairing Boiling Points to More
Polar Compounds
•Alkanes have low boiling points compared to
more polar compounds of comparable size

30. Example
CH3CH2 CH3 CH3CHO CH3CH2OH
Propane Acetaldehyde Ethanol
VDW VDW, DD VDW,DD,HB
MW=44 MW=44 MW=46
Bp= -42° C Bp=21° C Bp=79° C
Increasing surface area
Increasing boiling point

31. Melting Point
• Alkanes have low melting point compared
to more polar compounds
CH3CH2 CH3 CH3CHO
Propane Acetaldehyde
VDW VDW, DD
MW=44 MW=44
Mp= -190° C Mp=-121° CZ
Increasing strength of intermolecular forces
Increasing melting point

32. • Melting point increase as the number of
carbons increase because of increase of
surface area
CH3CH2 CH2 CH3 CH3 CH2 CH2 CH2 CH2 CH3
Butane Hexane
Mp=-138° C Mp=-95° C
Increasing surface area
Increasing boiling point

33. • Melting point increases with increased
symmetry
CH3CH2CH(CH3)2 (CH3)4C
Mp=-160° C Mp=-17° C
Increasing symmetry
Increasing melting point

34. Solubility in Water
• Alkanes are almost totally insoluble in
water
• They have low polarity and unable to form
hydrogen bonds
Solubility in Solvents
•Normally dissolve in solvent of low polarity
such as benzene. Chloroform, CCl4 and
other hydrocarbons.

36. 

37. 

41. 1.The root name is based on the longest
chain containing the halogen.
2.This root give the alkane part of the
name.
3.The type of halogen defines the halo
prefix, e.g. chloro-
4.The chain is numbered so as to give the
halogen the lowest possible number

42. 1.Functional group is an alkane, therefore
suffix = -ane
2.The longest continuous chain is C3
therefore root = prop
3.The substituent is a chlorine, therefore
prefix = chloro
4.The first point of difference rule
requires numbering from the right as
drawn, the substituent locant is 1-
1-chloropropane
CH3CH2CH2Cl
1-chloropropane