DEFINITIONS

• Chiral Carbon


  An asymmetric carbon atom/ a carbon atom bound to 4 different groups. This may also be called a chiral centre.

  
• Displayed Formula


  Shows all the bonds between every atom in the compound

  
• Chain isomers


  Isomers that occur due to the branching in the carbon chain
• Enantiomers


  Molecules which are non-superimposable mirror images of one another. Enantiomers have different effects on a plane of polarised light.
• Displayed formula


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

  
• Optical isomerism


  A type of stereoisomerism that occurs as a result of the presence of a chiral centre in a molecule. Optical isomers have different effects on a plane of polarised light.
• Empirical formula


  The smallest whole number ratio of atoms of each element in a compound
• Racemic Mixture (racemate)


  A mixture containing equal amounts of enantiomers.
• 1. Z isomerism


  A type of stereoisomerism that occurs due to the restricted rotation around the carbon double bond. This results in two different groups on one end of the bond and two different groups on the other end. If the highest priority groups for each carbon are found on the same side of the molecule, then it is the Z-isomer. If the highest priority groups for each carbon are found on opposite sides of the molecule, then it is the E-isomer

  
• Stereoisomers


  Compounds that only differ in their arrangement of atoms in space.
• Free-radical


  An uncharged molecule or atom with an unpaired valence electron
• Structural Formula


  Shows the arrangement of atoms in a molecule without the bonds drawn between them.

  
• Functional group


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


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


  Isomers that contain different functional groups. This means they 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
• Carbonyl group


  A functional group with a C=O double bond.

  
• Homologous series


  A series of compounds with the same functional group and similar chemical properties
• Curly Arrow


  Used in mechanisms to show the movement of a pair of electrons.
• Molecular formula


  Total number of atoms of each element in the compound
• Hydroxynitrile


  A molecule containing an alcohol group (OH) and a nitrile group (C≡N) bound to the same carbon. These can be formed in a nucleophilic addition reaction between a carbonyl and KCN followed by dilute acid (this reaction forms a mixture of enantiomers if an aldehyde or an unsymmetrical ketone is used).
• Position isomer


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

  
• Ketone


  A molecule containing the C=O functional group in the middle of the molecule.
• Skeletal formula


  A diagram representation of an organic compound in which lines represent bonds between atoms and atoms are represented by their symbol. Hydrogens are assumed to be at the end of the line if no other atomic symbol is present

  
• Nucleophile


  An electron pair donor.
• Stereoisomerism


  Occurs when two double bonded carbon atoms each have two different atoms or groups attached to them. Includes E/Z isomerism. This is a consequence of a restricted rotation around the C=C double bond
• Nucleophilic Addition


  A reaction in which an electrophilic π bond reacts with a nucleophile, breaking the π bond and forming 2 new σ bonds.
• 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

  
• Acid Anhydride


  A molecule containing the functional group below.
• Structural isomerism


  Structural isomers are compounds which have the same molecular formula but a different structural formula
• Acyl Chloride


  A molecule containing the functional group below.
• Catalytic converter


  A device fitted in a car to reduce the amount of emissions from an internal combustion engine. They use expensive metals like platinum and rhodium as the heterogeneous catalyst. The catalyst is mounted on a ceramic honeycomb to maximise the surface area
• Alcohol


  A molecule containing the OH functional group.
• Catalytic cracking


  A type of cracking that takes place at a slight pressure, high temperature and in the presence of a zeolite catalyst and is used mainly to produce motor fuels and aromatic hydrocarbons
• Biodiesel


  A mixture of methyl esters of long-chain carboxylic acids. Biodiesel is produced by reacting vegetable oils with methanol in the presence of a catalyst.
• Combustion of alkanes


  Combustion of alkanes releases energy. During combustion, the carbon and hydrogen in the fuels are oxidised. Alkanes can undergo complete or incomplete combustion. Water and carbon dioxide are the only products of the complete combustion, whereas carbon monoxide and carbon particulates can be produced in incomplete combustion
• Carboxylic Acids


  Molecules containing the -COOH functional group. Carboxylic acids are weak acids that form CO2 when reacted with carbonates.
• Cracking


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


  Molecules containing the R-COO-R' functional group which can be formed when carboxylic acids and alcohols react in the presence of an acid catalyst. Esters of glycerol (propane-1,2,3-triol) naturally occur in vegetable oils and animal fats and these esters can be hydrolysed in alkaline conditions to produce soaps and glycerol. Esters can be used to create solvents, plasticisers, perfumes and food flavourings.
• Crude oil


  A finite resource found in rocks. It is the remains of an ancient biomass consisting mainly of plankton that was buried in mud. Most of the compounds in crude oil are hydrocarbons