1. Nomenclature for Aliphatic Compounds
Exercise No. 2
Give possible isomers of the following aliphatic compounds and give their correct structure and IUPAC name
By: Dr Vipul B Kataria
For F. Y. B. Sc. Semester-I
US01CCHE01

2. H3 C – C – C - C H3 H2 H2 n-Butane H H3 C – C – C H3 – C H3 iso-Butane
Always remember: Valency of carbon is 4
(a)
C4H10 H3
C – C – C - C H3 H2 H2
1. The general formula for alkane is CnH2n+2
Where n = number of carbon atoms
n-Butane
2. Now see the given molecular formula: C4H10
3. Comparing with general formula of alkane
4. Calculation
4 carbons
Therefore C4H2(4)+2 = C4H10 H H3
C – C – C H3 –
How many carbon atoms? 4 Carbons
Arrange in possible chain: Continuous and branched C H3
2. Arrange hydrogens accordingly
iso-Butane
3. Name the compounds

3. C5H12 H3 C – C – C – C - C H3 H2 H2 H2 H2 H C – C – C – C H3 H3 C H3 C
Always remember: Valency of carbon is 4
(b)
C5H12 H3
C – C – C – C - C H3 H2 H2 H2
1. The general formula for alkane is CnH2n+2
Where n = number of carbon atoms
n-Pentane
2. Now see the given molecular formula: C5H12 H2 H
3. Comparing with general formula of alkane
C – C – C – C H3 H3
4. Calculation
5 carbons
Therefore C5H2(5)+2 = C5H12 C H3
iso-Pentane C H3
How many carbon atoms? 5 Carbons
Arrange in possible chain: Continuous and branched
C – C – C H3
2. Arrange hydrogens accordingly H3
3. Name the compounds C H3
neo-Pentane

4. C4H8 H2 C = C – C – C H3 H H H H H3 C – C = C – C H3 C H3 H2 C = C – C
Always remember: Valency of carbon is 4
(c)
C4H8 H2
C = C – C – C H3 H H
1. The general formula for alkene is CnH2n
Where n = number of carbon atoms
1-Butene
2. Now see the given molecular formula: C4H8
3. Comparing with general formula of alkene H H
4. Calculation
4 carbons
Therefore C4H2(4) = C4H8 H3
C – C = C – C H3
2-Butene
How many carbon atoms? 4 Carbons
Arrange in possible chain: Continuous and branched C H3
2. Arrange hydrogens accordingly H2
C = C – C H3
3. Name the compounds H
iso-Butene or 2-Methyl-1-propene

5. C5H10 (d) H2 C = C – C – C - C H3 H H2 H2 1-Pentene C H3 H3
Always remember: Valency of carbon is 4
(d)
C5H10 H2
C = C – C – C - C H3 H H2 H2
1-Pentene
1. The general formula for alkene is CnH2n
Where n = number of carbon atoms C H3
2. Now see the given molecular formula: C5H10
3. Comparing with general formula of alkene H3
C = C - C – C H3 H3
C - C = C – C - C H3 H2
4. Calculation
5 carbons
Therefore C5H2(5) = C5H10 H H H2
2-Methyl-1-Butene
2-Pentene C H3 C H3
1. How many carbon atoms? 5 Carbons
Arrange in possible chain: Continuous and branched H2
C = C - C – C H3 H3
C - C = C – C H3
2. Arrange hydrogens accordingly H H
3. Name the compounds
2-Methyl-2-Butene
3-Methyl-1-Butene