Organic chemistry - IGCSE Flashcards
General formula
A chemical formula which applies to a class of compounds, representing the composition of the atoms present in the compound
Homologous series
A series of compounds with the same functional group and similar chemical properties
Functional group
The group of atoms responsible for how a particular compound reacts
All compounds in the same homologous series have the same functional group
Repeat unit
The part of a polymer whose repetition would produce the complete polymer chain
Alkanes
The most common hydrocarbon found in crude oil
Alkanes have the general formula CnH2n+2
Alkenes
Hydrocarbons with a double bond between two of the carbon atoms in their chains, causing them to be unsaturated
They have the general formula CnH2n
Carboxylic acids
Organic compounds with the functional group -COOH
Ester
The product of a condensation reaction between a carboxylic acid and alcohol
They contain the functional group -COO- and are volatile compounds with distinct smell
Monomer
Small short chain molecules which can join together to form a long chain polyester
Hydrocarbons
Molecules that are made up of hydrogen and carbon atoms only
Saturated hydrocarbons
A hydrocarbon compound containing only single bonds between carbon atoms
Alkanes are saturated compounds
Unsaturated hydrocarbons
A compound that contains double or triple carbon bonds so that it doesn’t contain the maximum number of hydrogen atoms
Alkenes are unsaturated compounds
Polymer
Large long-chain molecules made up of lots of small monomers joined together by covalent bonds
Addition polymerisation
The reaction in which many small molecule monomers bond together to form a long chain polymer
Condensation polymerisation
Reactions in which monomers join together and lose small molecules, such as water
These reactions involve monomers with two functional groups
Cracking
A process that involves breaking down larger hydrocarbons to produce smaller more useful molecules
Cracking can be done by catalytic cracking or steam cracking
Catalytic cracking
Long-chain hydrocarbons are heated at 600-700C to turn them into a gas
The vapour is then passed over a silica or alumina catalyst
The long chain molecules split apart on the surface of the catalyst
Steam cracking
Long-chain hydrocarbons are heated to turn them into a gas
The hydrocarbon vapour is then mixed with steam and heated to a very high temp which caused them to split into smaller molecules
Combustion
The burning of a substance
Combustion of hydrogen fuels releases energy
During combustion, the carbon and hydrogen in the fuels are oxidised
Complete combustion
Combustion carried out in sufficient oxygen
Water and carbon dioxide are the only products of the complete combustion of a hydrocarbon
Incomplete combustion
Combustion which is carried out with insufficient oxygen
It can lead to the production of toxic carbon monoxide and carbon particulates
Addition reaction
A reaction in which at least two molecules combine together to form a larger molecule
Substitution reaction
A reaction in which a functional group of a compound is replaced by another functional group
