Definitions - Organic Chemistry I - AQA Chemistry A-level

Chain isomers

Isomers that occur due to the branching in the carbon chain.

Displayed formula

A type of structural isomer that shows all the bonds between every atom in the compound.

Empirical formula

The smallest whole number ratio of atoms of each element in a compound.

E-Z isomerism

A type of stereoisomerism that occurs due to the restricted rotation around the carbon double bond.

Free radical

An uncharged molecule or atom with an unpaired valence electron.

Functional group

The group of atoms responsible for the characteristic reactions of a particular compound.

Functional group isomers

Isomers that contain different functional groups and belong to different homologous series.

General formula

A type of empirical formula that represents the composition of any member of an entire class of compounds.

Homologous series

A series of compounds with the same functional group and similar chemical properties.

Molecular formula

Total number of atoms of each element in the compound.

Position isomer

Isomers where the carbon backbone of the isomers are the same but the important groups are at different positions on the backbone.

Skeletal formula

A diagram representation of an organic compound in which lines represent bonds between atoms and atoms are represented by their symbol.

Stereoisomerism

Occurs when two double bonded carbon atoms each have two different atoms or groups attached to them.

Structural formula

A formula which shows the arrangement of atoms in the molecule of a compound but does not show all the bonds between them.

Structural isomerism

Structural isomers are compounds which have the same molecular formula but a different structural formula.

Catalytic converter

A device fitted in a car to reduce the amount of emissions from an internal combustion engine.

Catalytic cracking

A type of cracking that takes place at high temperature and in the presence of a zeolite catalyst.

Combustion of alkanes

Releases energy and can undergo complete or incomplete combustion.

Cracking

A process which involves breaking C-C bonds in alkanes to produce shorter chained alkanes and alkenes.

Crude oil

A finite resource found in rocks and consists mainly of hydrocarbons.

experience high temperatures and pressures and takes millions of years.

Fractional distillation

A method of separating a mixture of substances according to their different boiling points.

Hydrocarbons

Compounds made up of carbon and hydrogen atoms only.

Saturated

Organic compounds are saturated if all the carbon-carbon bonds are single C-C bonds.

Thermal cracking

A type of cracking that takes place at high pressure and high temperature and produces a high percentage of alkenes.

Why Is fracking Bad?

cause earth quakes and environmental damage.

Test for Alkanes

Bromine water changes from brown to colourless

Catalytic Cracking

A process that uses a zeolite catalyst to break down large hydrocarbon molecules into smaller, more valuable products,

such as gasoline and alkenes,

at lower temperatures than thermal cracking.

formula for complete combustion

hydrocarbon with oxygen to produce carbon dioxide and water.

formula for incomplete combustion

hydrocarbon with insufficient oxygen to produce carbon monoxide and water.

and carbon particulates (unburnt hydrocarbons)

Chlorofluorocarbons (CFCs)

Chemicals containing carbon, chlorine and fluorine that contribute to ozone depletion.

why are carbon particulates bad?

Carbon particulates can pollute the environment

and cause asthma and cancer.

What is flue gas desulfurisation used for?

Flue gas desulfurisation is used to remove sulfurdioxide from the exhaust gases of fossil fuel power plants to reduce acid rain and air pollution.

How does flue gas desulfurisation work?

by neutralising sulfurdioxide with limestone or lime (calcium carbonate)

What is the formula for flue gas desulfurisation?

sulfur dioxide with calcium carbonate or calcium oxide, oxygen and water to make calcium sulphate.

Electrophile

Electron pair acceptor in an organic mechanism, attracted to areas with a lot of electrons.

Elimination

A reaction in which a molecule loses atoms or groups of atoms to form a C=C bond.

Free radical substitution

A photochemical reaction between halogens and alkanes to form halogenoalkanes.

Nucleophile

An atom or molecule that donates an electron pair to form a covalent bond.

Nucleophilic substitution

The reaction of a nucleophile with an electrophile, involving the replacement of one species with another.

Ozone

A molecule formed naturally in the upper atmosphere that absorbs ultraviolet radiation.

Ozone depletion

The process where chlorine atoms catalyze the decomposition of ozone.

Polar bond

A covalent bond where the electrons are not distributed equally, leading to slight charges.

Addition polymer

A polymer formed by addition polymerisation from monomers with C=C bonds.

Addition polymerisation

The process by which addition polymers are formed by joining monomers together.

Alkenes

Hydrocarbons with a double bond between two of the carbon atoms in their chain.

Carbocation

A carbon atom bearing a positive charge.

Major/minor products

Products formed from electrophilic addition based on the stability of carbocation intermediates.

Monomer

A short chain molecule that can bond to other monomers to form a polymer.

Plasticiser

A chemical added to polymers to improve flexibility and workability.

Polymer

Large long-chain molecules made up of lots of small monomers joined together.

Repeat unit

The part of a polymer whose repetition would produce the complete polymer chain.

Unsaturated

Organic compounds are unsaturated if they have at least one double carbon bond.

Alcohols

Compounds containing the functional group –OH.

Biofuel

A fuel derived from living matter.

Carbon-neutral fuel

A fuel with no net increase in carbon dioxide in the atmosphere.

Classification of alcohols

Alcohols classified as primary, secondary, or tertiary based on attached carbon groups.

Distillation

An experimental procedure used to separate a mixture of liquids based on their boiling points.

Fermentation of glucose

An industrial process to produce ethanol from glucose with yeast.

Hydration of alkenes

An industrial process to produce alcohols by reacting alkenes with steam.

Oxidation of alcohols

Alcohols can be oxidised with acidified potassium dichromate, yielding different products based on classification.

Aldehyde

A molecule containing the C=O functional group at the end of the molecule.

Alkene

A molecule containing the C=C functional group.

Carboxylic Acid

A molecule containing the COOH functional group.

Fingerprint Region

The region on an IR spectrum below 1500 cm-1, unique to each molecule.

Functional Group

A group of atoms responsible for the characteristic reactions of a compound.

Infrared Spectroscopy

A technique used to identify bonds and functional groups within a molecule.

Mass spectrometer

A device that provides information about isotopic mass and abundance.

Mass Spectrometry

A technique used to identify compounds and determine relative molecular mass.

Molecular Formula

The total number of atoms of each element in a compound.

Relative atomic mass

The average mass of an atom of an element compared to 1/12th the mass of carbon-12.

Relative molecular mass

The average mass of one molecule of an element or compound compared to 1/12th the mass of carbon-12.

Wavenumber

Represents the energy and frequency of infrared radiation absorbed by a bond in a molecule.

What is needed to initiate a chain reaction?

uv light and heat