Chem C21- Fuels and Heats of Reactions

Organic Chemistry

The study of the compounds of carbon

Groups of hydrocarbons

Alkanes, Alkenes, Alkynes

Saturated compound

compound in which there are only single bonds between carbons

Unsaturated compound

compounds in which there are one or more double or triple bonds between the carbon atoms in the molecule

Gaseous Alkanes

Methane, Ethane, Propane, Butane

General formula for alkanes

C_nH_2n+2

Homologous Series

A series of compounds of uniform chemical type

Showing gradation in physical properties

having a general formula for its members

Structural Isomers

compounds with the same molecular formula but different structural formulas

Alkenes

contain a carbon-carbon double bond

General formula for Alkenes

C_nH_2n

Alkynes

contain a carbon-carbon triple bond

Alkyne General formula

C_nH_2n-2

Ethyne/Acetylene use

oxyacetylene welding and cutting

Aliphatic compound

an organic compound that consists of open chains of carbon atoms and closed chain compounds (rings) that resemble them

Aromatic compounds

compounds that contain a benzene ring structure in their molecules

Order of fractions condensing during Fractional distillation

Refinery Gas, Light Gasoline(petrol), Naphtha, Kerosene/Paraffin, Diesel/Gas Oil, Lubricating Oil, Fuel Oil, Bitumen

Octane Number

a measure of the tendency of the fuel to resist knocking

Octane 100 eg

2,2,4-trimethylpentane

Octane 0 eg

Heptane

Ways to increase the octane number of petrol

Isomerisation, Catalytic Cracking, Reforming/cyclocyclisation, adding oxygenates

Isomerisation

the changing of straight hydrocarbons to branched hydrocarbons that have the same molecular formula/atom

Catalytic Cracking

the breaking down of long chain hydrocarbon molecules into short chain molecules for which there is greater demand

Reforming/Dehydrocyclisation

involves the use of catalysts to make ring compounds

Adding Oxygenates

Methanol, Ethanol, MTBE added to petrol to increase its octane number

Manufacturing Hydrogen Gas

Steam reforming of Natural Gas, Electrolysis of Water, Reforming/dehydrocyclisation

Uses of hydrogen gas

Manufacturing of Ammonia, Hydrogenating vegetable fats, fuel