Organic Chemistry

• Crude Oil is formed over millions of years from what?

  The fossilised remains of plankton
• Where is crude oil found?

  In porous rocks in the Earth's crust
• Crude oil is a finite resource used to produce what?

  Fuels and other chemicals
• What are fuels?

  Substances that can be burned to release energy
• Most of the compounds in crude oil are what?

  Hydrocarbons
• What are hydrocarbons?

  Molecules made of only carbon and hydrogen atoms
• The properties of hydrocarbons, and the way that hydrocarbons can be used a fuels get affected by what?

  The varying size of hydrocarbon molecules
• Describe the properties of hydrocarbons as they get larger?

  They are more viscous , have a higher boiling point , they are less volatile and they ignite less easily
• Crude oil can be separated into different fractions through what process?

  Fractional distillation
• When crude oil gets separated into different fractions, what does each fraction contain?

  hydrocarbon molecules with a similar number of carbon atoms
• When crude oil gets separated into different fractions, what does each fraction contain?

  hydrocarbon molecules with a similar number of carbon atoms
• Most of the hydrocarbons obtained from fractional distillation are what?

  Alkanes
• Alkanes only contain single bonds. Because of this, what are they described as?

  Saturated hydrocarbons
• What is the general formula for Alkanes ?

  C ₙ H ₂ₙ₊₂
• Alkanes can be drawn with a single line between atoms. What does this line represent?

  a single covalent bond
• How many bonds can hydrogen atoms make?

  1
• How many bonds can carbon atoms make?

  4
• What is methane made up of?

  4 hydrogen atoms and 1 carbon atom
• What is ethane made up?

  2 carbon atoms and 6 hydrogen atoms
• What is propane made up of?

  3 carbon atoms and 8 hydrogen atoms
• What is Butane made up of?

  4 carbon atoms and 10 hydrogen atoms
• Why are shorter chain alkanes in greater demand to be used as fuels?

  Because shorter chain alkanes release more energy more quickly by burning
• Most fuels are compounds of what?

  Carbon and hydrogen (Many also contain sulfur)
• What is combustion?

  Its basically just burning
• What happens during the combustion of hydrocarbon fuels?

  Carbon and hydrogen are oxidised , energy is released and waste products are produced, which are released into the atmosphere
• What happen if combustion is not complete?

  Carbon monoxide , unburnt fuels and solid particles containing soot may be released
• What is carbon monoxide?

  A colourless , odourless and toxic gas
• What hazards can solid particles in the air, called particulates, cause?

  They can cause global dimming as they reduce the amount of sunlight reaching earth's surface , and they can damage people's lungs
• What happens to nitrogen in the air due to the high temperature reached when fuels burn?

  Nitrogen in the air can react with oxygen to form nitrogen oxides. These gases cause respiratory problems , and react with rain water to form acid rain (Which damages plants and buildings)
• Describe how sulfur can be removed?

  Sulfur can be removed from fuels before burning (in motor vehicles) and removed from the waste gases after combustion (in power stations)