2.2 Organic chemistry

• What form is crude oil in?

  Liquid form
• what is crude oil?

  Crude oil is a mixture of many different compounds. Most of the compounds are hydrocarbons .
• why is crude oil a finite resource?

  crude oil is a finite resource because it takes a million years to reproduce
• How can crude oil be separated?

  The compounds in crude oil can be separated by distillation
• what is a hydrocarbon

  Hydrocarbon is a molecule that only contains the elements carbon and hydrogen
• What is a homologous series

  A group of organic compounds that have similar chemical properties, due to the having the same functional group
• Why are alkanes saturated?

  An alkane only has single covalent bonds, there are no double bonds or triple bonds
• What is the general formula for an alkane?

  CnH2n+2
• What do names of alkanes always end with?


  -ane
• First 4 alkanes

  1. Methane
  2. Ethane
  3. Propane
  4. Butane
• First 4 alkanes in formula?

  1. CH4
  2. C2H6
  3. C3H8
  4. C4H10
• As the chain length of alkanes increases they become more:

  • More viscous
  • Less flammable
  • Less volatile
  • Higher boiling and melting point
• What is the word equation for the combustion of a hydrocarbon?

  Hydrocarbon + Oxygen -> Carbon Dioxide + Water
• Is combustion an exothermic or endothermic reaction?

  Exothermic
• During a combustion reaction, are carbon and hydrogen oxidised or reduced?

  Oxidised- Carbon (C) becomes CO2, whilst hydrogen (H2) becomes H2O. Both have gained oxygen, so have been oxidised
• How is crude oil made?

  1. Crude oil formed from remains of dead plants- plankton
  2. Organic remains covered by mud and buried in earth
  3. Over million years, these organic remains were compressed under lots of heat and pressure
  4. The heat and pressure chemically change these remain into crude oil
• How does fractional distillation works?

  1. Heat crude oil at a very high temperature so compounds evaporate from liquid to gas
  2. Hot gaseous hydrocarbons rise up the fractioning column
  3. As they rise, they cool down because the top is cooler than the bottom and condense
  4. The longer chain hydrocarbon condense at the bottom of the fractioning column
• What is usually at the top of the fractioning column?

  Petrol and kerosene
• what is usually at the bottom of the fractioning column?

  diesel, heavy fuel oil and bitumen
• What is cracking?


  Cracking is the process in which larger chain hydrocarbons are split into smaller, more useful hydrocarbons.
• What type of reaction is cracking?

  Thermal decomposition reaction -it involves using heat to break something apart.
• What are two different types of cracking?

  Catalytic cracking

  Steam cracking
• Catalytic cracking


  - First, some long chain alkanes are heated until they vaporise into a gas

  -Then they're passed over a hot, powdered aluminiumoxide catalyst -This breaks the long chain alkanes into a small chain alkane and an alkene
• How is steam cracking different to catalytic cracking?

  Steam cracking is different because there is no catalyst involved. Instead the vaporised long chain alkane is mixed with steam at very high temperatures.
• Alkenes

  • Hydrocarbons and also an example of a homologous series
  • Has a double bonds between two carbon atoms
  • unsaturated
• Is alkenes more or less reactive than alkanes?


  alkenes are more reactive
• Why is alkenes more reactive?

  they have a double bond
• What is the test to distinguish between an alkane and an alkene?

  Bromine water test
• What happens to the bromine water if alkene is present?


  Bromine water turns from orange to colourless because the bromine react with the alkene so solution loses all its orange colour.
• what happens to alkane when put into bromine water?


  Bromine water stays orange colour because alkane not reactive enough to react with bromine water
• What type of reaction does an alkene do?

  Addition reaction
• addition reaction between alkene and hydrogen

  Reacting an alkene with hydrogen gas, and a catalyst, will produce an alkane
• Addition reaction between an alkene and water

  Reacting an alkene with water (at a high temperature and with a catalyst) will produce an alcohol
• What is the general formula for an alkene?

  CnH2n
• what is the functionAl group of an alkene ?

  C=C double bond
• What are the 4 short alkenes?

  1. ethene
  2. propene
  3. butene
  4. pentene
• what are the first 4 short alkene in formula?

  1. ethene - C2H4
  2. propene- C3H6
  3. Butene- C4H8
  4. pentene- C5H10
• What is the general formula for an alcohol?

  CnH(2n+1) OH
• what is the functional group of alcohol?

  Hydroxyl (-OH)
• what are the first 4 short alcohol

  1. methanol
  2. ethanol
  3. propanol
  4. butanol