Isomers

• Isomers


  • Compounds with same molecular formulae but different structural formulae
  • Different arrangements of atoms or positions of a functional group, such as carbon-carbon double bond
  • Different physical properties such as mp and bp
  • Longest chain has to be lesser than total no. of carbon atoms
• Saturated hydrocarbons


  • contain only carbon-carbon single bonds, carbon atoms form single covalent bonds with 4 other atoms
• Unsaturated hydrocarbons


  • contain at least one carbon-carbon double bond
  • atoms can be added across each carbon-carbon double bond via addition reaction to form new compounds
• Aqueous Bromine


  • aqueous Bromine can be used to distinguish between Alkanes and alkenes
  • remains brown when mixed with an alkane
  • decolourises when mixed with an alkene
• Fats and Oils


  • Animal fats and vegetable fats have similar chemical properties but different physical properties
  • Two types of fats, saturated and unsaturated
  • Saturated contains carbon-carbon single bonds, unsaturated contains carbon-carbon double bonds
  • Both fats and oils are polysaturated since they contain more than one carbon-carbon double bond
• Manufacture of Margarine


  • Vegetable oils contain many carbon-carbon double bonds
  • Vegetable oil exists as liquid at room temperature
  • Vegetable oils are made into solid margarine through hydrogenation
  • Hydrogenation in the presence of nickel catalyst at 150 degree celcius converts some carbon-carbon double bonds into single bonds
  • Margarine is more saturated and has higher molecular mass than vegetable oil
  • Margarine has higher melting point and exists as solid a room temp
• Fats


  • Fats play an important role in our body, it acts as an energy source
  • Unsaturated fats is healthier than saturated fats