Summary Grade 12 IEB Physical Sciences - Organic Chemistry Notes (Chemistry Section G)

Organic chemistry
= will have C, H, O, some N, some F
Exception: CO2
Non-metals = molecules (IMFs involved)

Functional group
= is an atom or group of atoms that form the centre of chemical activity in the molecule.
E.g. C bonded to -O-H = alcohols
C bonded to -Br = alkyl halide
E.g. Ethanol




Hydrocarbon
= is a compound containing only carbon and hydrogen atoms.
E.g. crude oil (fossil fuels)

Homologous series
= is a series of similar compounds which have the same functional group and same general
formula, in which each member differs from the previous one by a single CH2 unit.
Example: Alcohols

1. Methanol
Molecular formula: CH4O
Semi structural formula: CH3OH




2. Ethanol
Semi structural formula: CH3CH2OH

, 3. Propan-1-ol
Semi structural formula: CH3CH2CH2OH




General formula: CnH2n+1
Same functional group Homologous series
Differ by a single CH2

Carbon
Element number 6
Symbol: C


p
2 s

1 s



Hybridization



p
2 s

1 s




= tetrahedral in shape

,Prefixes in organic nomenclature (naming)

1 Mono
2 Di
3 Tri
4 Tetra
5 Penta
6 Hexa
7 Hepta
8 Octa

Root names in organic nomenclature (naming)
= tells us how long the longest continuous carbon chain is

1 Meth
2 Eth
3 Prop
4 But
5 Pent
6 Hex
7 Hept
8 Oct

, Alkanes
“Ane”
= hydrocarbons with only Carbon Carbon single bonds
General formula: CnH2n+2

1. Methane
Molecular formula: CH4
Structural formula:




2. Ethane
Molecular formula: C2H6
Semi structural formula: CH3CH3
Structural formula:




3. Propane
Molecular formula: C3H8
Semi structural formula: CH3CH2CH3
Structural formula:




4. Butane
Molecular formula: C4H10
Semi structural formula: CH3CH2CH2CH3
Structural formula: