General Definitions
- Organic Chemistry is the study of compounds of Carbon.
- Hydrocarbons are carbons consisting of carbon and hydrogen only, bonded together covalently. They are used as fuel and feedstock for the chemical industry. Main Sources: Coal, Methane, Crude Oil.
- Structural isomers are compounds that have the same molecular formula but different structural formulas.
Homologous Series is defined as:
- A series of compounds of uniform chemical type.
- Showing gradations in physical properties.
- Having a general formula for its members.
- Each member having similar chemical properties & preparation.
- Each member differing from the previous by a CH2 unit.
Aliphatic Compounds
Definition: An aliphatic compound is a hydrocarbon that consists of straight and branched chains of carbon atom, or rings of carbon atoms that do not contain a benzene ring.
Alkanes
- General Formula: CnH2n+2
- All saturated compounds. i.e Single bonds only
Alkenes
- General Formula: CnH2n
- All unsaturated compounds. i.e Contains double bonds
Alkynes
- General Formula: CnH2n-2
- Contains a triple bond
Aromatic Compounds
Definition: Aromatic compounds are compounds that contain a benzene ring structure in their molecules.
Important aromatic compounds:
- MethylBenzene: C7H8
- EthylBenzene C8H10
Methylbenzene
- Liquid at room temperature
- Insoluble in water
- Dissolves in cyclohexane
Hydrogen
There are two main methods for manufacturing hydrogen.
-
Steam reforming of Natural Gas. This involves reacting steam with methane in the presence of a suitable catalyst:
CH4 + H2O –> 3H2 + CO - Electrolysis of Water. This involves passing an electric current through water: H2O –> H2 + 1/2 O2