CHEMISTRY OF CHEMISTRY OF HYDROCARBONSHYDROCARBONS

DefinitionsDefinitions

Organic compound – a molecular Organic compound – a molecular compound of carboncompound of carbon

Hydrocarbon – compounds that are Hydrocarbon – compounds that are formed from carbon and hydrogenformed from carbon and hydrogen

Carbon and hydrogen account for 90% Carbon and hydrogen account for 90% of all the biological matter on EARTH!of all the biological matter on EARTH!

Natural Organic Natural Organic CompoundsCompounds

Synthetic Organic Synthetic Organic CompoundsCompounds

Medicines - painkillers, cough Medicines - painkillers, cough syrup, antidepressantssyrup, antidepressants

Perfumes, food flavouringsPerfumes, food flavourings Materials – rubber, plasticMaterials – rubber, plastic Fabrics – nylon, polyesterFabrics – nylon, polyester

Sources of HydrocarbonsSources of Hydrocarbons

WoodWood Fermentation of plantsFermentation of plants Fossil fuelsFossil fuels

• Petroleum (crude oil) – formed from Petroleum (crude oil) – formed from the remains of marine-based the remains of marine-based microscopic plantsmicroscopic plants

• Coal – formed from remains of land-Coal – formed from remains of land-based plantsbased plants

Properties of CarbonProperties of Carbon

1.1. Carbon has four bonding electrons.Carbon has four bonding electrons.

2.2. Carbon can form strong single, Carbon can form strong single, double, and triple bonds with itself.double, and triple bonds with itself.

3.3. Carbon atoms can bond together to Carbon atoms can bond together to form a variety of geometrical form a variety of geometrical structuresstructures

Representing Structures and Representing Structures and bondingbonding

1.1. Expanded molecular formulaExpanded molecular formula• Shows the groupings of atomsShows the groupings of atoms

Example: propane Example: propane

– – CC33HH8,8, the chemical formula, does not the chemical formula, does not show how atoms are bonded togethershow how atoms are bonded together

-expanded molecular formula - CH-expanded molecular formula - CH3 3 CHCH2 2 CHCH33

illustrates the atomic arrangementillustrates the atomic arrangement

IsomersIsomers

• Isomers – compounds that have the Isomers – compounds that have the same formula, but different same formula, but different structural arrangementstructural arrangement

Example: How many isomers are there Example: How many isomers are there for Cfor C55HH1414??

Answer: 5Answer: 5

2.2. Using structural Using structural models to models to represent represent HydrocarbonsHydrocarbons

o 3D representation 3D representation of the structure of of the structure of the compoundthe compound

3.3. Using Structural Diagrams to Using Structural Diagrams to represent hydrocarbonsrepresent hydrocarbons

Complete structural diagram – shows how all atoms are bonded to one another

Condensed StructuralDiagram-shows bonds betweenthe carbon atoms but not between the carbon and hydrogenatoms

Line structural diagram- End of each line, and the points at which the lines meet, represent carbon atoms