11. Organic Chemistry Basic Concepts

• covalent bond - a shared pair of electrons between two bonding atoms
• A covalent bond can be broken in 2 different ways: homolytic fission and heterolytic fission
• Homolytic fission - each of the bonded atoms takes one of the shared pair of electrons from the bond. Radicals are formed (an atom or group of atoms with unpaired electrons)
• Heterolytic fission - one of the bonded atoms takes both of the electrons from the bond. Ions are formed
• Addition reaction - Two reactant molecules join together to form one product.
• Substitution reaction - An atom or group of atoms is replaced by a different atom or group of atoms.
• Elimination reaction - A small molecule is removed from a larger molecule.
• hydrocarbon - a compound containing carbon and hydrogen atoms only
• saturated - single bonds only
• unsaturated - contains carbon to carbon double or triple bonds
• Homologous series - a family of compounds with similar chemical properties whose successive members differ by the addition of a CH2 group
• Functional group - a part of the organic molecule that is largely responsible for the molecules chemical properties
• Aliphatic - carbon atoms are joined to each other in unbranched or branched chains, or non-aromatic rings e.g. alkanes, alkenes
• Alicyclic - carbon atoms are joined to each other in a non-aromatic ring with or without branches
• Aromatic - some or all of the carbon atoms are found in a benzene ring
• What is this?

  A benzene ring

  
• What is this?

  A benzene ring

  
• Displayed formula - shows the relative positioning of all the atoms in a molecule and the bonds between them
• What formula is this?

  Displayed formula

  
• Structural formula - shows the minimal detail for the arrangement of atoms in a molecule
• What formula is this?

  Structural formula

  
• Skeletal formula - a simplified organic formula
• What formula is this?

  Skeletal formula

  
• Molecular formula - shows the number and type of atoms of each element present in a molecule
• What formula is this?

  Molecular formula

  
• Empirical formula - shows the simplest whole number ratio of atoms of each element
• What formula is this?

  Empirical formula

  
• Alkyl groups - side chains attached to a longer, continuous carbon chain
• Structural isomers - molecules with the same molecular formula but different structural formula. They have similar chemical properties but different physical properties like melting point
• Curly arrows - used to show the movement of an electron pair when bonds are broken or made