1. Naming Alkanes

2. Parent Chain Alkyl group Cycloalkane
OUTCOME QUESTION(S):
C NAMING AND DRAWING
Name and draw structural models of simple and
branched alkanes.
Include: complete structural formula, molecular
formula, general formula, isomers
Name and draw structural models of simple and branched
alkenes and alkynes.
Compare and contrast the structure and uses of aromatic
and aliphatic hydrocarbons.
Vocabulary & Concepts
Parent Chain Alkyl group Cycloalkane

3. International Union of Pure And Applied Chemistry
Naming Alkanes
Standard naming rules are set by the International Union of Pure and Applied Chemistry (IUPAC)
The longest continuous carbon chain is the parent chain.
Chains are named using prefixes for carbon number and a unique suffix for the compound type.
Prefixes must be memorized
- ane
Eth
2 carbons single bonded
C – C H
Ethane
IUPAC Naming
International Union of Pure And Applied Chemistry

4. General formula – CnH2n+2
Alkanes
Suffix ane
General formula – CnH2n+2
Used to calculate the total carbons and hydrogens in the alkane
Decane
C10H22
What trends do you see?
Methane
Ethane
Propane
Butane
Pentane
Hexane
Heptane
Octane
Nonane
CH4
CH3CH3
CH3CH2CH3
CH3CH2CH2CH3
CH3CH2CH2CH2CH3
CH3CH2CH2CH2CH2CH3
CH3CH2CH2CH2CH2CH2CH3
CH3CH2CH2CH2CH2CH2CH2CH3
C9H20
CnH2n+2
n = 10
2n+2 = 2(10)+2 = 22

5. Remember – 4 bonds for each carbon
Drawing Alkanes
Use line bonds to connect the correct carbon number in a “carbon skeleton.”
Add hydrogen in the correct number for each carbon atom.
3 carbons single bonded
Propane
C3H8
Molecular Formula H H H
Complete
Structural Formula 2 3 H
C – C – C H H 1 4 H H
Remember – 4 bonds for each carbon

6. Condensed will be the most useful form for practicing
Draw pentane:
5 carbons single bonded H H H H H
Complete
Structural Formula H
C – C – C – C – C H 1 2 3 4 5 H H H H H
Condensed Formula
C – C – C – C – C H3 H2 H2 H2 H3 1 2 3 4 5
Condensed will be the most useful form for practicing
C5H12
Molecular Formula (CnH2n+2)

7. This is a methyl group attached to a hexane parent chain
Another alkane branched off the parent chain is called an Alkyl group (substituent).
The alkyl branch follows the same naming system BUT ends in –yl to show that it is a substituent.
C - C - C - C - C - C C
Branch
Name
–CH3
methyl
–C2H5 or –CH2CH3
ethyl
–C3H7 or –CH2CH2CH3
propyl
This is a methyl group attached to a hexane parent chain

8. C C - C - C - C - C - C Naming Branched Alkanes
Find the longest carbon chain (parent chain).
Number the carbons in the parent from the end that gives the lowest number to the branch(es).
For simplicity only a carbon skeleton is being used
– don’t forget about the hydrogens
Parent chain can be bent – as long as it is the longest continuous chain
C - C - C - C - C - C C 1 6 5 2 3 4 3 4 2 5 1 6

9. C C - C - C - C - C - C Naming Branched Alkanes 3 - ethyl hexane
Name each branch including the number of the parent carbon it is attached to (to show position).
Name the parent chain.
Hyphens separate position numbers from components
3 -
ethyl
hexane
C - C - C - C - C - C C 1 2
Branch
Name
–CH3
methyl
–C2H5 or –CH2CH3
ethyl
–C3H7 or –CH2CH2CH3
propyl 3 4 5 6

10. Breakdown each piece of the name starting with the parent chain…
Draw the structural formula for 2-methylhexane.
Breakdown each piece of the name starting with the parent chain… C H3
C – C – C – C – C – C H3 H H2 H2 H2 H3 1 2 3 4 5 6
2-methylhexane

11. 4-ethyl-2-methylhexane
Use basic prefixes (di, tri) to show multiples of one type of alkyl group and parent numbers for each.
The alkyls are named in alphabetical order
Commas are used to separate numbers
(eg. 3-ethyl-4,4-dimethylnonane)
4-ethyl-2-methylhexane 6 C C 5
C - C - C - C
C - C - 4 3 2 1

12. 5-ethyl-2,4-dimethyloctane
Draw the carbon skeleton of 5-ethyl-2,4-dimethyloctane
It doesn’t matter if the branch off an alkane goes up or down – have fun with it! C C C 4
C - C -
C - C - C - C - C - C 1 2 3 5 6 7 8 C
5-ethyl-2,4-dimethyloctane

13. Draw a structural formula for 2,4-dimethylpentane
C – C – C – C – C H3 H H2 H H3 1 2 3 4 5
2,4-dimethylpentane
CH3CH(CH3)CH2CH(CH3)CH3 1 2 3 4 5
This is what it would look like as a condensed formula – brackets are used to indicate branches off the previous carbon

14. 3-ethyl-2,7-dimethyl-4-propyloctane
Draw: 3-ethyl-2,7-dimethyl-4-propyloctane
Don’t get scared – break it down C H3 H2 C H3 H2
C – C – C – C – C – C – C – C H3 H H H H2 H2 H H3 1 2 3 4 5 6 7 8 C C H2 H3 H3
3-ethyl-2,7-dimethyl-4-propyloctane

15. Name the following: 2 1 3 4 5 6 7 8
3,3,5-
trimethyl
octane

16. If you can’t “see” the condensed – draw it out first…
Take this condensed formula and name the compound.
CH3CH2CH2CH(C2H5)CH2C(CH3)2CH3 7 6 5 4 3 2 1
If you can’t “see” the condensed – draw it out first… 7 6 5 4 3 2 1
4-ethyl-2,2-dimethylheptane

17. Any carbon in the circle can be #1 – so start at the branch
CYCLOALKANES
One more little thing…
Same naming rules – but add prefix “cyclo”
Name the carbon ring first, then number the carbons so as to give the alkyl groups the lowest set of numbers. C 4 1-
methyl
cyclo
butane 1 3 2 1 C 6 2
Any carbon in the circle can be #1 – so start at the branch
cyclo
hexane 5 3 4

18. Name the following: 1,3- dimethyl cyclo pentane 1,2,3- trimethyl cyclo5 2 C 4 1 3
1,2,3-
trimethyl
cyclo
propane 2 1
Remember to count in the direction that gives the lowest numbers to the branches…

19. Parent Chain Alkyl group Cycloalkane
CAN YOU / HAVE YOU?
C NAMING AND DRAWING
Name and draw structural models of simple and
branched alkanes.
Include: complete structural formula, molecular
formula, general formula, isomers
Name and draw structural models of simple and branched
alkenes and alkynes.
Compare and contrast the structure and uses of aromatic
and aliphatic hydrocarbons.
Vocabulary & Concepts
Parent Chain Alkyl group Cycloalkane