Chapter 11

• Carbon

  • Forms bonds with its own atoms, including single, double or triple bonds
  • Has high C-C bond energy
  • Bonds in a variety of ways: rings, chains and cages
  • Limits the number of carbon atoms in a simple covalent compound
  • Can form a continuous number of carbon atoms in a giant covalent structure

  
• Hydrocarbon

  • A compound that contains only carbon and hydrogen atoms
  • Alkanes have single C-C bonds (saturated)
  • Alkenes have double C-C bonds (unsaturated)

  
• Homologous series

  • A family of similar properties whose members differ by a CH2 group - they have the same general formula
  • Have similar chemical properties
  • Have a gradual change in physical properties
• Functional group

  • An atom or a group of atoms in a molecule that is responsible for its chemical reactions
  • Examples: alkane, alkene, halogenoalkane, alcohol, carboxylic acid

  
• General formula

  • Alkane: CnH2n+2
  • Alkene: CnH2n
  • Haloalkane: CnH2n+1X

  
• Functional group is an atom or group of atoms in a molecule that is responsible for its chemical reactions
• Hydrocarbons are compounds which only contain carbon and hydrogen
• • Carbon forms single, double and triple bonds to other carbon atoms
  • Carbon can form chains of carbon atoms
  • Carbon forms bonds to other atoms such as oxygen, nitrogen and the halogens

  
• Aliphatic

  Carbon atoms are joined by an unbranched or straight or non-aromatic chain

  
• Alicyclic

  Carbon atoms are joined to each other in rings (cyclic structure)

  
• Aromatic

  Some or all of the carbon atoms are found in a benzene ring

  
• Stem

  Indicates the number of carbon atoms in the largest chain present in the compound

  
• Prefix

  Added before the stem as part of the name
• Suffix

  Added after the stem as part of the name
• Alkyl group

  Formed by removing a hydrogen from an alkane
• Naming aliphatic alkanes: 1) Use -ane suffix, 2) Identify longest continuous stem and choose appropriate stem, 3) Identify the attached chain to the parent chain (alkyl group) and add as prefix, 4) Add number before alkyl group to show which C atom it is bonded to

  
• Naming alicyclic alkanes: Same rules as aliphatic alkanes, but use 'cyclo-' prefix to show carbons are arranged in a ring structure

  
• Naming alkenes: Same rules as aliphatic alkanes, but use '-ene' suffix to show the C=C bond

  
• Molecular formula

  Shows the type and number of atoms of elements present in a molecule, e.g. C2H6O

  
• Empirical formula

  The simplest whole-number ratio of the atoms of each element present in a compound
• General formula

  The simplest algebraic formula for any member of a homologous series
• Displayed formula

  Shows the relative positioning of all of the atoms in a molecule and the bonds between them

  
• Skeletal formula

  The simplest organic formula, with all bonds removed and all carbon and hydrogen atoms labelled from the carbon chain

  
• Formulas for organic compounds

  • 1a) Hexanoic acid

  1b) Benzene

  1. Ethanol

  3a) 2,3-Dimethylheptane

  3b) 2,3-Dichlorobutane

  
• Structural isomerism

  Compounds have the same molecular formula but different structural formulas

  Types: chain isomerism, positional isomerism, functional group isomerism
• Chain isomerism

  Compounds have the same molecular formula but their longest hydrocarbon chain is not the same, caused by branching
• Positional isomerism

  Differences in the position of a functional group, which can be located on different carbons
• Functional group isomerism

  Different functional groups result in the same molecular formula
• Isomers have different chemical properties as they have different functional groups
• Homolytic fission

  Breaking a covalent bond in a way that each atom takes an electron from the bond to form 2 radicals (species with an unpaired electron)
• Heterolytic fission

  Breaking a covalent bond in a way that the more electronegative atom takes both electrons from the bond to form a negative ion and a positive ion
• Curly arrows

  Show the movement of electrons

  Single-headed (fish-hook) arrows or half-curly arrows show homolytic fission

  Double-headed arrows show heterolytic fission, forming positive and negative ions
• Addition reactions

  Two reactants combine to form one product
• Elimination reactions

  A small molecule is removed from a larger molecule
• Substitution reactions

  An atom or group of atoms in a compound are replaced by another atom or group of atoms