Edexcel IGCSE Chemistry Alkenes

ALKENES

Unsaturated Hydrocarbon

  • Compounds which have carbon-carbon double bond
  • Compounds made up of carbon and hydrogen only

GENERAL FORMAULE  CnH2n

Useful to make polymers, alkanes, alcohols

Alkanes (1)

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MANUFACTURE OF ETHANOL

 FERMENTATIONHYDRATION OF ETHENE
REACTION

Glucose                      Ethanol + carbon dioxide

C6H12O6                        2C2H5OH + 2CO2

Ethene + Steam      Ethanol
REACTION CONDITIONSGentle temperature and pressure. Anaerobic conditionsNickel catalyst and high temperature and pressure
ADVANTAGESUses renewable resources like sugarcane. Less dependent on fossil fuels and due to less energy requirements do not harm the environment.It is a continuous process. It is rapid more efficient and have 100% atom economy. Produces more pure ethanol
DISADVANTAGESIt is a batch process. The ethanol has to be distilled from time to time as high concentration will kill the yeast. The reaction is slow and produces impure ethanol. Also the atom economy is not 100%Requires ethene which is dependent on crude oil. Uses non renewable resources.

REACTIONS OF ALKENES

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References:

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