Organic chemistry

• Organic Chemistry


  The study of carbon-containing compounds and their properties
• Hydrocarbons


  Organic compounds that contain the elements carbon and hydrogen only
• Homologous series


  A series of organic molecules in which each member differs by -CH₂. Each homologous series have similar chemical properties & same general formula
• Homologous series to be studied

  • Alkanes
  • Alkenes
  • Alkynes
  • Primary amines
  • Haloalkanes
  • Alcohols
  • Carboxylic acids
  • Esters
  • Aldehydes
  • Ketones
• Alkanes


  • Methane
  • Ethane
  • Propane
  • Butane
• Alkenes


  • Ethene
  • Propene
  • But-1-ene
  • But-2-ene
• Alkynes


  • Ethyne
  • Propyne
  • But-1-yne
• Alkanes


  • Hydrocarbon
  • C-C saturated
• Alkenes


  • Hydrocarbon
  • C=C unsaturated
• Alkynes


  • Hydrocarbon
  • C≡C unsaturated
• Naming alkanes


  1. Prefix indicates number of carbon atoms

  2. Suffix is -ane
• Methene cannot exist as alkenes have at least one C=C
• Alkene homologous series


  • Each member differs by -CH₂
  • Similar chemical properties
  • Same general formula
• Naming alkynes


  1. Prefix indicates number of carbon atoms

  2. Suffix is -yne
• Naming unsaturated hydrocarbons


  1. Start numbering from the end closest to the double/triple bond

  2. Double/triple bond gets the lowest possible number

  3. Main chain must contain the double/triple bond
• Unsaturated hydrocarbon names


  • But-1-ene
  • Pent-2-ene
  • Pent-1-yne
• Structural isomers


  Compounds with the same molecular formula but different structural formula
• Structural isomers of C4H10

  • Butane
  • 2-methylpropane
• For organic compounds with four or more carbon atoms, there is more than one way of bonding the atoms together
• Structural isomers of 1-chlorobutane


  • 1-chlorobutane
  • 2-chlorobutane
  • 2-chloromethylpropane
• Unsaturated hydrocarbons


  Not bonded to the maximum number of atoms possible
• Alkenes


  • Contain at least one carbon-carbon double bond
  • Suffix is -ene
• Alkynes


  • Contain at least one carbon-carbon triple bond
  • Suffix is -yne
• Alcohols


  • Contain a hydroxyl group (-OH)
  • Suffix is -ol
• First 3 alkanols


  • Methanol
  • Ethanol
  • Propan-1-ol
• CH3


  Carbony! (aldehyde)
• Alcohols are a homologous series that contain a hydroxyl group (-OH). Due to the polarized nature of the functional group alcohols have relatively high boiling points and considerable water solubility.
• Alcohols


  When naming alcohols, a similar systematic naming process to the one used for alkanes, alkenes and alkynes applies. The number of carbon atoms in the molecule is indicated by the prefix, e.g. meth-, eth-, prop-, but-. However, the suffix of the name of an alcohol is always '-ol'.
• Methanol


  • H-C-O-H
  • H-C-H
• For alkanes + alcohols, ↑ chair length + b.p. This is because there are more dispersion forces between molecules. ↑ energy needed to break the IMF'S. ↑ b.p.
• Complete combustion of propan-1-ol

  C3H₂OH (1) + 9/2O2 (g) → 3CO2 (g) + 4 H2O (g)
• Ethanol solubility in water

  Polar hydroxyl F.G. forms H-bonds with water. ethanol is soluble in water
• Alcohols have ↑b.p than alkanes. (with equivalent no. of c atoms). This is because alconds have a polar hydroxyl F. G (-0-H).. has H-bonds between molecules :. ↑ IMF :. more energy needed : 1 b.p.
• Ethanoic acid and propan-1-ol boiling points

  Ethanoic acid forms dimers. 2x CH₂ Loon join by 2x H-bonds. molar mass doubles ↑ dispersion forces 1. ↑ energy needed to break IMF'S : Tb.p. Propan-tol forms H-bonds between molecules but doesn't form a dimer. .. Weaker mmf's :. ✓ energy needed ..vb.p.
• Esterification is also referred to as a condensation reaction because water is produced.
• Formation of propyl pentanoate

  Pentanoic acid + Propan-1-ol → Propyl pentanoate + water
• The ester formed from the reaction of 2-butanol and propanoic acid in the presence of concentrated sulfuric acid is 2-butyl propanoate.
• Carboxylic acids have higher boiling points than esters due to stronger hydrogen bonding between carboxylic acid molecules.
• Aldehydes and ketones


  Aldehydes have the carbonyl group at the end of the chain, ketones have it in the middle. The carbonyl group is polar, leading to higher boiling points than alkanes.
• Aldehydes


  • Methanal
  • Ethanal
  • Propanal