Organic chemistry

• Saturated hydrocarbons :

  hydrocarbons whose molecules contain single bonds between carbon atoms in the molecule and are made up only from carbon and hydrogen
• general formula for alkanes:

  CnH2n+2
• Alkane functional group:

  single bonds between carbon atoms
• Usaturated hydrocarbons:

  hydrocarbons whose molecules contain double bonds between carbon atoms in the molecule and are made up only from carbon and hydrogen atoms
• General formula for alkenes:

  CnH2n
• functional group for alkenes:

  a double bond between carbon atoms
• Homologous series is a group of organic compounds that have :

  -the same general formula

  -the same functional group

  -similar chemical properties

  -different physical properties due to increasing molar mass

  -each compound increases by CH2 unit from the previous one
• a functional group is an atom or group of atoms that determine the chemical properties of a compound
• Isomers are organic compounds who have the same molecular formula but different structure formula
• Alkanes are unreactive organic compounds due to the presence of strong single covalent bonds between carbon atoms in their molecules
• the empirical formula of alkenes is CH2 because there are as many hydrogen atoms as carbon atoms in every alkene
• the empirical formula of alkanes is not constant because the general formula of alkanes cant be divided by 2
• preparation of of alkanes:

  • Prepare from fractional distillation from crude oil
  • Alkene + Hydrogen = Alkane
  • Type of reaction : preparation Reagent: Hydrogen gas
  • condition of reaction: Nickel catalyst, 200 degree

  example:

  C2H4+H2=C2H6
• Preparation for alkenes :

  • From alcohols
  • type of reaction: elimination or dehydration reaction
  • catalyst: concentrated sulphuric acid
  • temperature : 180 degrees
  • Alcohol=Alkene + Water
• separation of crude oil into fractions:

  • the temperature increases gradually
  • the components of crude oil evaporate and rise up through the fractional column
  • every component separates according to its boiling point
  • different fractions have different boiling points
  • vapor passes through bubble caps through fractionating column and rise up
  • the components condense when they get to the part of the Collin that has lower temperature than their boiling point
• refinery gas: used for heating and cooking
• gasoline(fuel): used for fuel for cars
• naphtha: used for making plastics and chemicals
• kerosine: fuel for airplanes
• diesel: fuel for buses and trains
• fuel oil : ships
• bitumen: making roads and covering roofs
• general formula for alcohols : CnH2n+1OH
• alcohols : orgarlic compounds containing one hydroxyl group or more
• molecular formula for alcohols: CnH2n+O
• Fermentation process is renewable and uses sucrose or glucose
• fermentation is a batch process
• fermentation process conditions:

  catalyst: yeast

  temperature: 35 degrees

  pressure: 1
• advantages:

  • carbohydrates are renewable
  • less heat energy required
  • can be used in countries with no oil reserves
• disadvantages of fermentation:

  • slower rate of reaction
  • impure alcohol produced
  • carbon dioxide is produced
  • it takes a long time
• hydration process is a non renewable resource and uses ethene and steam
• hydration is a continuous process
• conditions of hydration process:

  catalyst: phosphoric acid

  temperature: 300 degrees

  pressure: 60 -70 ATM
• advantages of hydration process

  faster rate of reaction

  pure alcohol produced

  no carbon dioxide produced
• disadvantages of hydration process

  fossil fuels are non renewable

  large amount of energy and pressure is required
• oxidation of alcohols: 


  alcohols can be oxidized to carboxylic acid and water
• reagents of oxidation of alcohols

  potassium dichromate acidified with sulfuric acid color change from orange to green

  potassium permanganate acidified with sulfuric acid color change from purple to colorless
• general formula for carboxylic acid

  CnH2n+1COOH
• Molecular formula for carboxylic acid

  CnH2nO2