alcohols

• What regeants can you use to have cyanide as a nucleophile?

  Potassium cyanide(KCN) and Sodium cyanide(NaCN) with dilute acid (HCl)to give H+ ion
• What do alcohols have a higher bp?

  There are hydrogen bonds between the molecule( formed from OH)
• What is the general formula of alcohols?

  CnH2n+OH
• What is always a product of the oxidation of alcohols?

  H2O
• what intermolecular forces do aldehydes,ketones and carboxylic acids have?

  van der waals and dipole-dipole
• what can primary alcohols be oxidised to?

  aldehydes which can be oxidised further to carboxylic acids
• secondary alcohols oxidation


  can be oxidised to ketones
• tertiary alcohols can't be oxidised further
• what is used during oxidation

  acidified potassium dichromate.Orange to green solution if the alcohol has been oxidised.
• Equations for oxidation


  structural formula + [O] to represent oxidation reagent.Balance oxygens with H20 .
• Two methods to form ethanol

  crude oil-fractions cracked .Ethene produced then hydrated.

  fermentation-yeast uses glucose in anaerobic respiration to produce ethanol and carbon dioxide.

  However, the ethanol produced is not pure and hence has to be separated from impurities by fractional distillation.
• Fermentation reaction


  CO2 absorbed-Photosynthesis-6CO2 + 6H2O → C6H12O6 + 6O2. (6CO2 molecules absorbed)

  CO2 released-fermentation-C6H12O6 (aq) 2C2H5OH(aq) + 2CO2(g) (6 molecules of CO2 released)

  combustion-2C2H5OH + 6 O2 → 4 CO2 + 6H2O (l) in total 4 molecules of CO2 released.
• What are biofuels


  fuels made from living material immeditaely after it has died.ethanol made from fermentation is a biofuel.
• Advantages of biofuel instead of fossil fuels

  -biofuels more renewable

  -considered carbon neutral as CO2 produced compensated for CO2 absorbed by plants grown
• Disadvantages of biofuel instead of fossil fuels

  -petrol engines used for transportation need to be modified to operate on biofuels

  -land used to grow biofuel crops instead of other crops-could lead to food shortages

  -fossil fuels still used in the biofuel production chain.