organic chem

• Hydrocarbons


  Compounds that contain only carbon and hydrogen atoms
• Nomenclature


  The set of rules that outline how different organic compounds should be named and how their formulas are represented
• Ways of writing and representing organic compounds

  • Empirical formula
  • Molecular formula
  • General formula
  • Structural formula
  • Displayed formula
  • Skeletal formula
• Homologous series


  • All members follow a general formula and react in a very similar way
  • Each consecutive member differs by CH2 and there is an increase in boiling points as chain length increases
• Functional group


  Allows a molecule to be recognised as being able to react chemically in a certain way as a result of that group
• Stem


  The prefix of the chemical tells you the length of the longest unbroken chain of carbon atoms in the compound
• Functional group ending


  Tells you the functional group present
• Halogen prefix


  • Fluorine: Fluoro-
  • Chlorine: Chloro-
  • Bromine: Bromo-
  • Iodine: Iodo-
• Alkyl groups


  Carbon side chains that are branches from the longest carbon chain, represented by a prefix at the start of the word
• General IUPAC naming rules

  • Functional groups and side chains are given, if necessary, with the number corresponding to the carbon they are attached to
  • Numbers are separated by commas
  • Numbers and words are separated by hyphens
  • If more than one particular side chain or functional group is present then one of the following prefixes is added: di- (2), tri- (3), tetra- (4), etc.
  • The carbon chain is numbered in ascending order from the end of the chain nearest a functional group
  • If multiple prefixes are present, they are included in alphabetical order
• Addition reaction


  The reactants combine to form a single product
• Substitution reaction


  One functional group is replaced by a different functional group
• Oxidation


  A species loses at least one electron, and is oxidised
• Reduction


  A species gains at least one electron, and is reduced
• Polymerisation


  A reaction in which many small molecules, known as monomers, join together to form a long, repeating molecule called a polymer
• Reaction mechanism


  Shows the movement of electrons within a reaction, shown with curly arrows
• Isomers


  Molecules with the same molecular formula but a different arrangement of atoms within the molecule
• Structural isomers


  Have the same molecular formula but a different structural arrangement of atoms
• Position isomers


  Have the functional group of the molecule in a different position of the carbon chain
• Functional group isomers


  Have the same molecular formula but the molecules have a different functional group
• Stereoisomers


  Have the same structural formula but have a different spatial arrangement of atoms and bonds
• 1. Z isomerism


  A type of stereoisomerism that occurs due to the limited rotation around a double carbon bond
• Cahn-Ingold-Prelog (CIP) priority rules


  Used to determine if a molecule is the E or Z isomer based on the priority of different groups
• Cis- and trans- isomers

  Stereoisomers named based on whether the groups are on the same side or different sides, when there are hydrogen atoms present
• Alkanes


  Saturated hydrocarbons where all carbon-carbon bonds are single bonds, part of a homologous series with the general formula CnH2n+2
• Cycloalkanes


  Saturated hydrocarbons that are an exception to the general formula CnH2n+2
• Fractional distillation


  1. Crude oil is vapourised and fed into the fractionating column

  2. Vapours rise, cool and condense

  3. Products are siphoned off for different uses
• Products with short carbon chains have lower boiling points, so rise higher up the column before condensing and are collected at the top
• Products with long carbon chains have higher boiling points, so don't rise very far up the column before condensing and are collected at the bottom
• Cracking


  Longer carbon chains are broken down to form smaller, more useful molecules by breaking carbon-carbon bonds under harsh reaction conditions
• Thermal cracking


  Produces a high proportion of alkanes and alkenes using high temperatures around 1200 K and pressures around 7000 kPa
• Catalytic cracking


  Produces aromatic compounds with carbon rings using lower temperatures around 720 K and a zeolite catalyst
• Combustion of alkanes


  1. With sufficient oxygen, they undergo complete combustion to produce carbon dioxide and water

  2. With insufficient oxygen, they undergo incomplete combustion to produce carbon monoxide or carbon particulates alongside water
• Carbon monoxide is a toxic, gaseous product that is dangerous as it replaces oxygen in the blood, starving the brain and other organs of oxygen and causing people to suffocate
• Oxides of nitrogen and sulfur are also produced as byproducts of alkane combustion along with carbon particulates from unburnt fuel
• Zeolite catalyst


  Used to compensate for less harsh conditions in combustion of alkanes
• Alkanes


  • They release a lot of energy when burned
  • They undergo complete combustion to produce carbon dioxide and water
• If the oxygen present is insufficient, combustion is incomplete and carbon monoxide or carbon particulates are produced alongside water
• Carbon monoxide


  A toxic, gaseous product that is especially dangerous to humans as it is odourless and colourless. It replaces oxygen in the blood, starving the brain and other organs of oxygen and causing people to suffocate
• Oxides of nitrogen and sulfur are also produced as a byproduct of alkane combustion along with carbon particulates from unburnt fuel. In clouds, these oxides can react with water and form dilute acids, which result in acid rain