organic reactions

• Types of hydrocarbons


  • Alkanes
  • Alkenes

  
• Alkanes


  • Only single C-C bonds
  • Can form isomers if > 3 C
  • Saturated
• Alkenes


  • Contain C=C bond
  • Must have 2 or more C atoms to exist
  • Unsaturated
• General formula for alkanes


  CnH2n+2
• General formula for alkenes


  CnH2n

  
• Cyclic molecules


  • Cyclohexane: C6H12
  • Benzene: C6H6

  
• Benzene


  Unsaturated cyclic hydrocarbon

  
• Benzene structure


  • 3 valence electrons form bonds, 4th being delocalised around all 6 C atoms
  • All bonds 1.5 in length

  
• Homologous series


  • Alkenes
  • Haloalkanes
  • Alcohols
  • Amines (primary only)

  
• Functional groups


  C=C double bond<|>-X (X = F, Cl, Br, I)<|>-OH<|>-NH₂
• Alcohols


  • Hydroxyl group replaces H atom of hydrocarbon
• Amines


  • Amino group replaces H atom of hydrocarbon
• Carbonyl groups


  Functional groups containing C=O

  
• Carbonyl group functional groups

  • Esters
  • Aldehydes
  • Ketones
  • Carboxylic Acids
  • Amides (primary only)

  
• Functional groups of carbonyl compounds

  • COO- (ester)<|>-CHO (aldehyde)<|>-CO- (ketone)<|>-COOH (carboxylic acid)<|>-CONH₂ (amide)

  
• Carboxylic acids


  • Carbonyl attached to hydroxyl group
  • -COOH always at end and no.1 of chain

  
• Amides


  • Carbonyl attached to amino group

  
• Melting point


  Temperature when a substance changes from solid to liquid
• Boiling point


  Temperature when a substance changes from liquid to gas
• Viscosity


  A liquid’s ability to resist pouring or flowing
• Stronger intermolecular bonding results in higher melting and boiling points
• Types of intermolecular bonds (in order of strength)

  • Dispersion forces
  • Dipole-dipole interactions
  • Hydrogen bonding

  
• Hydrogen bonding occurs with H-F, H-O, H-N

  
• Trends in size and arrangement

  • Increasing molecular size increases strength of temporary dipoles
  • Branching decreases strength of dispersion forces
• Families of organic compounds

  • Alkanes
  • Alkenes
  • Haloalkanes
  • Alcohols
  • Amines
  • Carboxylic acids
  • Esters
  • Aldehydes
  • Ketones

  
• Alkanes


  • Non-polar, soluble, low melting and boiling points
• Alkenes


  • Non-polar, soluble, slightly lower melting and boiling points than alkanes
• Haloalkanes


  • Polar, dipole-dipole bonding, low melting and boiling points
• Alcohols


  • Polar, hydrogen bonding, high melting and boiling points
• Amines and amides


  • Polar, hydrogen bonding, high melting and boiling points
• Carboxylic acids


  • Polar, hydrogen bonding, very high melting and boiling points

  
• Esters, Aldehydes, Ketones


  • Polar, dipole-dipole bonding, medium melting and boiling points

  
• Reactions of alkanes


  1. Combustion

  2. Substitution
• Reactions of haloalkanes


  Substitution
• Reactions of alkenes


  1. Combustion

  2. Addition
• Reactions of alcohols


  1. Combustion

  2. Oxidation
• Reactions of carboxylic acids

  1. Ionisation

  2. Esterification

  3. Hydrolysis

  4. Transesterification
• Combustion


  Reacts with air/O₂(g)
• Substitution


  Atom of functional group in an organic compound is replaced by another atom or functional group
• Oxidation


  Process of increasing the oxygen content or decreasing the hydrogen content of a substance