AS Chemistry Alchols Mind Map

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  • Created by: E
  • Created on: 22-04-15 11:08
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  • Alcohols
    • Ethanol Production
      • Fermentation C6H12O6 -------->2CH3CH2OH+2CO2
        • Slow
        • Batch process
        • Renewable raw materials
        • Makes impure copper (purified by fractional distillation)
        • Normal pressure
        • 30-40'C
        • Micro-organisms (yest) to supply enzyme in absence of oxygen
        • Made from sugar, maize, or corn
        • Anaerobic conditions (without oxygen)
      • Direct Hydration CH2=CH2+H20-------->CH3CH2OH
        • Fast
        • Continuous process
        • Non-renewable raw materials
        • Makes pure ethanol
        • High pressure
        • 300'C
        • Concentrated phosphoric acid catalyst
        • Made from crude oil
      • ***CARBON NEUTRAL*** The CO2 used in photosynthesis when growing plants for sugar is the same amount of combustion of alcohol and fermentation.
    • Introduction and Classification of Alcohols
      • The Basics
        • Have the function group -OH
        • Have the suffix -ol
        • Have the prefix hydroxy-
      • Classification
        • Primary
          • The carbon attached to the OH is attached to only one other carbon.
          • eg Propan-1-ol CH2CH2CH2OH
        • Secondary
          • eg Propan-2-ol CH3CH(OH)CH3
          • The carbon attached to the OH is attached to 2 other carbons.
        • Tertiary
          • eg 2-Methyl propan-2-ol CH3C(CH3)(OH)CH3
          • The carbon attached to the OH is attached to 3 other carbons.
    • Oxidation of Alchols
      • Primary Alcohols
        • Oxidised to aldehyde and  then to carboxylic acid.
        • Oxidation of primary alcohol to an aldehyde (distillation) CH3CH2CH2OH+[o]---->CH3CH2H-C=O+H20
        • [o] is distill potassium dichromate. (H+/K2Cr2O7)
        • Oxidation of aldehyde to carboxylic acid (reflux) CH3CH2H-C=O+[o]---------->CH3CH2OH-C=O
      • Secondary Alcohols
        • Oxidised to a ketone only.
        • Don't need to distil/reflux, simply heat.
        • Oxidation of secondary alcohol to ketone. CH3CH(OH)CH3---->CH3C(=O)CH3+H2O
        • Uses acidified potassium dichromate. (H+/K2Cr2O7)
      • Tertiary Alcohols
        • CAN'T BE OXIDISED.
        • There are no hydrogen atoms attached to the carbon bearing the hydroxyl group and so no oxidation can occur.
        • There is no reaction between tertiary alcohols and acidified potassium dichromate.
      • Chemical Test for Alcohols
        • H+/K2Cr2O7 (potassium dichromate) is orange. It is reduced to Cr^3+ which is green.
        • Primary and secondary alcohols react with potassium dichromate so would go from orange to green.
        • Tertiary alcohols DON'T react with potassium dichromate so no colour change would occur.
    • Chemical Test for Aldehydes
      • Test 1-Tollens Reagent
        • 2).Used to identify an aldehyde.
        • 3).Aldehyde is oxidised to carboxylic acid.
        • 4).Ag+ ions reduced to Ag which creates a 'silver mirror'.
        • 5).Ketone can't be oxidised so there is no change.
        • 6).So if silver mirror is produced it was an aldehyde. If not, it was a ketone.
        • 1).Silver nitrate dissolved in dilute aqueous ammonia.
      • Fehling's Solution
        • 2).Used to identify an aldehyde.
        • 3).Cu2+ in fehlings is reduced to Cu2O which produces a red precipitate.
        • 4).Ketone can't be oxidised so there is no change.
        • 5).So if there is a red precipitate it was an aldehyde, if not it was a ketone.
        • 1).Blue solution containing copper(II) ions in an alkaline solution (NaOH)

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