organic chemistry

• What is a hydrocarbon?

  a compound of hydrogen and carbon only
• What is the empirical formula?

  simplest whole number ratio of each element
• What is the empirical formula of ethene?

  CH2
• What is the molecular formulae?

  actual number of each element
• What is teh molecular formula of ethene?

  C2H4
• What is the general formula for alkenes?

  CnH2n
• What is the general formula of alkanes?

  CnH2n+2
• What is the structural formula?

  formula which shows arrangement of atoms in molecul
• What is teh structural formula of ethene?

  CH2CH2
• What is the displayed formula?

  shows symbols for each atom in compound
• What is a homologous series?

  series of compound with same general formula and similar properties
• What is a functional group?

  group of atoms responsible for chemical reactions of a compound
• What is an isomer?

  compounds with same molecular formula, different displayed formula
• What is the suffix of alkanes?

  ane
• What is the suffix of alkenes?

  ene
• What is the suffix of alcohols?

  ol
• Crude oil is a complex mixture of hydrocarbons
• Crude oil contains molecules in which carbon atoms are in chains or rings
• Crude oil is a finite resource
• Where is the hottest area of a fractional distillation column?

  at the bottom
• What is the order of uses from top to bottom from crude oil in a fractional distillation column?

  refinery gases, petrol, kerosene, diesel, fuel oil, bitumen
• What are refinery gases used for?

  domestic heating and cooking
• What is petrol used for?

  fuel for cars
• What is kerosene used for?

  fuel for aircraft
• What is diesel used for?

  fuel for some cars and trains
• What is fuel oil used for?

  fuel for large ships and power stations
• What is bitumen used for?

  surface roads and roofs
• Why do we do cracking after fractional distillation?

  to make shorter chains which meet demands as more useful
• What are the conditions for cracking?

  aluminium oxide as catalyst and 600-700 degrees
• How does the length of molecules and temperature relate?

  shorter the molecules, lower the temperature where fraction vaporises and condenses
• What type of boiling point do short molecules have?

  low
• The shorter the chain lengths of molecules, the less viscous it is
• The longer the chain length of the molecules, the darker the colour
• Where in the fractional distillation column are the molecules darker?

  bottom
• What is fuel?

  a substance that releases heat energy when burned
• What are the products of complete combustion?

  CO2 and H20
• What is incomplete combustion?

  when there's not enough oxygen so some fuel doesn't burn
• What is released in incomplete combustion?

  unburnt fuel and carbon monoxide
• In car engines, the temperature reached is high enough to allow nitrogen and oxygen from air to react which forms oxides of nitrogen
• Explain how the combustion of some impurities in hydrocarbon fuels results in the formation of sulfur dioxide?

  mosts fuel contain carbon, hydrogen and sulfur, this means when fuels are burnt sulfur is oxidised to produce sulfur dioxide