ORGANIC CHEM

• what is a hydrocarbon


  contains hydrogen and carbon atoms
• what is crude oil?


  a finite resources - a mixture of hydrocarbons
• properties of hydrocarbons


  longer chain hydrocarbons are more viscous (flow very slowly)

  shorter chain are less viscous

  shorter chain are more volatile

  shorter chain more flammable

  shorter chain have low bp
• combustion of hydrocarbons


  hydrocarbon+oxygen---> carbon dioxide+water
• why is crude oil separated (fractional distillation)


  the fractions can be processed to produce fuels and feedstock for the petrochemical industry
• steps of fractional distillation?


  • the oil is heated (at very high temperature until it boils) until most of it has turned into gas
  • crude oil vapour is fed into the fractional distillation column
  • the columns hotter at the bottom and cooler at the top
  • hydrocarbon vapours rise up the column, condense when bp is reached
• what happens to long chain hydrocarbons in fractional distillation


  longer chain have high bp so are removed from the bottom of the column as its the hottest
• what happens to short chain hydrocarbons in fractional distillation


  short chains have low bp so are removed from the top as gases
• uses of crude oil are


  oil produces the fuel for most modern transport such has petrol and diesel, kerosene, heavy fuel oil
• the use of crude oil for the petrochemical industry


  uses some of the hydrocarbons from crude oil as feedstock to make new compounds for polymers solvents lubricants detergents
• what is cracking?


  the splitting up of long chain hydrocarbons.
• cracking is a type of what decomposition


  thermal decomposition as you break molecules by heating them
• why do we do cracking?


  there is a high demand for short chain hydrocarbons to be used as fuels, so we convert long chain hydrocarbons to short chain as long chain is not very flammable meaning its not a good feel
• catalytic cracking


  high temperature and a catalyst to speed up reaction
• steam cracking


  high temperature and steam
• features of alkenes


  have a double c=c bound

  cnh2n
• test for alkenes


  shake alkene with bromine water

  turns colourless when present
• combustion of alkenes


  alkene+oxygen---> carbon +carbon monozide+carbon + water
• what does incomplete combustion result in


  smoky yellow flame
• difference between alkane and alkene


  alkane is saturated as it has a single bond

  alkene is unstirred as it has a double c=c bond
• name alkenes


  methene

  ethene

  propene

  butene
• name alkanes


  methane

  ethane

  propane

  butane
• whats hydrogenation


  the addition of hydrogen to alkenes
• what hydragation


  addition of water to alkene producing an alcohol
• ethene and bromine make


  dibrocmoethane
• functional group of alcohols


  -OH
• name alcohols


  methanol

  ethanol

  proponol

  butanol
• properties of alcohols


  flammable as the undergo complete combustion

  1-4 all solule in water, natural ph

  as number of carbon atoms increase solubility decreases
• alcohol reaction with sodium


  methanol+sodium---> sodium methoxide+hydrogen

  ethanol+sodium---> sodium ethanoxide +hdyrogen
• what are alcohol used for


  solvent and fuels
• what can ethanol be made by


  fermentation
• equation for ethanol


  sugar---->ethanol+carbon dioxide
• conditions for fermentation


  happens fastest at 37 degrees

  acidic solutions

  under anaerobic condtions

  so enzyme doesn't denature
• how does alchols react with oxidising agent


  methanol---> methanoic acid+water

  propanol---> propanoic acid+water
• function group of carboxylic acids


  -COOH
• carboxylic acids react with carbonates to form


  ethnic acid+sodium carbonate---> sodium ethanoate+water+carbondioxide
• how does carboxylic acids react in water


  can dissolve in water
• what doe carboxylic acids produce in water


  H+ ions giving an acidic solution
• how are they weak acids in water


  partially ionising, also have a higher ph then strong acids like hydrochloric acid
• functional group of esters


  -coo-