1. Organic Formulae… Cyclohexane has 6 carbons and 12 hydrogens.
Make a model of the structure following these rules:
Each hydrogen has 1 bond
Each carbon has 4 bonds
How can this structure be represented in your notes?

2. Organic Formulae… Molecular formula C6H12
Shows only the number of each element
Gives no information on the structure of the compound

3. Organic Formulae… Empirical formula CH2
Shows only the ratio of each element
Gives no information on the structure of the compound

4. Organic Formulae… Displayed or Full Structural
Shows EVERY bond in the compound
Gives the most detail of any of the formulae types

5. Organic Formulae… Structural Shows what is attached to each carbon
Gives the NECESSARY information on the structure

6. Organic Formulae… Skeletal Shows no C-H bonds
Never shows the symbol for carbon
Shows the arrangement of atoms/groups clearly

7. Organic Formulae… Here are the formulae types for ethanoic acid:
Molecular: C2H4O2
Empirical: CH2O
Structural: CH3COOH
Displayed:
Skeletal:

8. Organic Formulae…
Isomers are a set of compounds that have the same number of each element but a different arrangement of the atoms.
Make these with the modelling kits. How many isomers did I miss out?

9. Organic Formulae…
Structural isomers have the same molecular formula but different structural formulae
& OH OH

10. Organic Formulae…
Stereoisomers have the same molecular and structural formulae but a different arrangement around a central atom or double bond.
There are two types of stereoisomers that we need to consider currently:
E/Z isomers
Cis/Trans isomers

11. Organic Formulae… E/Z isomers require a double bond X Y X Y
This is the E-isomer.
The functional groups are on different sides of the double bond Y
This is the Z-isomer.
The functional groups are on the same side of the double bond X Y

12. Organic Formulae… In Cis/Trans isomers X = Y X Y X Y
This is the Trans-isomer.
The functional groups are on different sides of the double bond Y
This is the Cis-isomer.
The functional groups are on the same side of the double bond X Y

13. Organic Formulae…
Now that we can draw the compounds we need to be able to name them!
But first, as always, some definitions to learn.

14. Organic Formulae…
Functional group: set of atoms responsible for the characteristic reaction of a compound
Homologous Series: a set of compound with the same functional group where the molecular formula increases by CH2 each time

15. Organic Formulae…
Alkyl: a functional group where the general formula is CnH2n+1
Aliphatic: straight chain (no rings)
Alicyclic: rings
Aromatic: contains benzene

16. Organic Formulae… Functional groups you need to know
Atoms Compound Prefix/Suffix
-OH = alcohol -ol or hydroxy-
-X = haloalkane halo-
-CHO = aldehyde -al
-COOH = carboxylic acid
-oic acid
-CO = ketone -one

17. Organic Formulae… Identify the LONGEST carbon chain 7
Identify the functional groups present methyl- and chloro-
Identify which carbon each functional group attaches to the base carbon chain 2/6 and 3/5 Cl

18. Organic Formulae… Identify the LONGEST carbon chain 7
Identify the functional groups present methyl- and chloro-
Identify which carbon each functional group attaches to the base carbon chain 2/6 and 3/5 Cl

19. Organic Formulae… With 7 carbons the base alkane is heptane.
2-chloro-3-methylheptane
All numbers MUST be separated from letters with a dash (-) Cl

20. Organic Formulae… Identify the LONGEST carbon chain
Identify the functional groups present
Identify which carbon each functional group attaches to the base carbon chain

21. Organic Formulae… Identify the LONGEST carbon chain 6
Identify the functional groups present 2x methyl
Identify which carbon each functional group attaches to the base carbon chain 2 and 3

22. Organic Formulae… With 6 carbons the base alkane is hexane.
2,3-dimethylhexane
All numbers MUST be separated from each other with a comma (,)

23. Organic Formulae… Identify the LONGEST carbon chain
Identify the functional groups present
Identify which carbon each functional group attaches to the base carbon chain

24. Organic Formulae… Identify the LONGEST carbon chain 5
Identify the functional groups present -ene
Identify which carbon each functional group attaches to the base carbon chain 2/3

25. Organic Formulae… Identify the LONGEST carbon chain 5
Identify the functional groups present -ene
Identify which carbon each functional group attaches to the base carbon chain 2

26. Organic Formulae… With 5 carbons the base alkane is pentane:
pent-2-ene
Any functional group with a suffix needs to have its number first

27. Organic Formulae… Identify the LONGEST carbon chain
Identify the functional groups present
Identify which carbon each functional group attaches to the base carbon chain O OH H

28. Organic Formulae… Identify the LONGEST carbon chain 4
Identify the functional groups present aldehyde, alcohol, methyl
Identify which carbon each functional group attaches to the base carbon chain 1 , 3, 2 O OH H

29. Organic Formulae… With 4 carbons the base is butane.
2-methyl-3-hydroxybutanal
The aldehyde group takes preference over the alcohol for the suffix. O OH H