crude oil

• in what process is crude oil separated?

  fractional distillation?
• what happens to crude oil in fractionating column

  heated and evaporates and condenses at different temperatures where they have similar hydrocarbon lengths
• what comes out at the top of crude oil fractional distillation and what is it used for?

  refinery gases used for heating and cooking
• what comes out second from the top when separating crude oil and what is it used for

  gasoline/petrol , fuel for cars
• what comes out third down when separating crude oil and what is it used for?

  Kerosene, fuel for aircraft
• what comes out third from the bottom when separating crude oil and what is it used for?

  Diesel, fuel for some cars and for trains
• what comes out second from the bottom when separating crude oil and what is it used for?

  fuel oil, used for large ships and fuel for some power stations
• what comes out at the bottom when separating crude oil and what is it used for?

  bitumen, to surface roads and roofs
• what are properties of shorter hydrocarbon chains?

  lower boiling point, less viscous
• what are properties of longer hydrocarbon chains?

  more viscous, darker, higher boiling point
• what is a fuel?

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

  CO2 and H2O
• what happens in incomplete combustion of hydrocarbons?

  some of the fuel doesn't burn, solid particles of carbon (soot) are released, carbon monoxide is released
• why is carbon monoxide poisonous?

  it prevents red blood cells carrying oxygen around body, causes difficulty breathing and death
• what happens in a car engine because the temp is so high?(include info ab nitrogen)

  nitrogen and oxygen from air react to make NO and NO2
• what is sometimes produced as a by product of burning fuel?

  sulfur dioxide
• why can sulfur dioxide and nitrogen oxides be bad?

  they react with rain water to form H+ ions which causes acid rain.
• why is acid rain bad?

  corrodes rocks and buildings, alters ph in soil or rivers which effects ecosystems
• what catalyst is used for cracking

  alumina or silica
• what is the reason for cracking?

  to produce smaller more useful molecules
• what conditions are needed for cracking?

  high temperature and high pressure,
• how does cracking work

  passed over a hot catalyst or mixed with steam and heated to around 700 celsius so that thermal decomposition reactions can occur
• what are the products of cracking?

  alkanes and alkenes
• why is cracking necessary in terms of demand and supply?

  demand for smaller chained alkanes is much greater however supply for longer chained alkanes is much higher