Please enable JavaScript.

Coggle requires JavaScript to display documents.

Module 6 Chapter 26 (26.3 Carboxylic Acids (Carboxyl group (Carboxylic…

- - - - Carbonyl functional group at end of chain
      - Carbon of carbonyl group attached to 2 Hydrogens
      - Aldehyde group written as CHO
      - Simplest= Methanal HCHO
    - - Carbonyl functional group joined to 2 carbons
      - Ketone group written as CO
      - Simplest= Propanone CH3COCH3 (AKA Acetone- in nail varnish removers)
  - - - It is polar as Oxygen more electronegative than Carbon
      - Electron density lies closer to oxygen than carbon (slightly +ve)
      - This means carbonyls react with some nucleophiles
      - Nucleophile is attracted to and attacks slightly +ve carbon resulting in addition across C=O double bond (nucleophilic addition)
      - Formed of σ-bond (direct overlap of orbitals between C and O and a π bond (overlap of p-orbitals above and below plane of C and O atoms
    - - Added across C=O bond
      - NaCN and H2SO4 used to provide HCN as it's colourless and extremely poisonous
      - Helpful as lengthens carbon chain
      - Product contains a hydroxy group (-OH) and a nitrile group (C≡N)
      - Classed as hydroxynitriles
- - - - Carboxylic Acid + Metal -> Carboxylate Salt + Hydrogen
      - e.g. Propanoic Acid + Mg (s) -> Magnesium Propanoate + H2 (g)
  - - - Carboxylic Acid+ Metal Oxide -> Salt + Water
      - e.g Ethanoic Acid + CaO (s) -> Calcium Ethanoate + H2O (l)
    - - Carboxylic Acid+ Alkali -> Salt + Water
      - Ethanoic Acid + NaOH (aq) -> Sodium Ethanoate + H2O (l)
    - - Carboxylic Acid+ Carbonate -> Salt + Water + Carbon Dioxide
      - e.g. Methanoic Acid + CaCO3 (aq) -> Calcium Methanoate + H2O (l) + CO2 (g)
      - This is a test for the carboxyl group- no other organic functional group is acidic enough to liberate CO2 from carbonates
- - - - Carboxylic acid + Alcohol -> Ester + Water
      - Conditions- Heat and Conc. H2SO4
      - Type- Condensation, elimination or esterification
      - Reverse it using hydrolysis
    - - Acid
        
        Ester + Water -> Carboxylic Acid + Alcohol
        
        Conditions- heat under reflux, H2SO4 (aq) catalyst
        
        Excess water to drive equilibrium to right
      - Alkaline
        
        AKA Sponification
        
        Conditions- Heat under reflux with OH- (aq)
        
        Ester + OH- -> Carboxylate Salt + Alcohol
  - - - Carboxylic Acid + Thionyl Chloride (SOCl2)- > Acyl Chloride + SO2 + HCl (Fume Cupboard as products harmful)
    - - Very reactive useful as easy to convert with good yields
      - React with nucleophiles by losing Cl but retaining C=O
      - 1) Acyl Chloride + Alcohol -> Ester + H2O
      - 2) Carboxylic acid not reactive enough to form esters with phenols so Acyl Chloride or Acid Anhydride must be used Acyl Chloride+ Phenol -> Ester + HCl
      - 3) Acyl Chloride + Water -> Carboxylic Acid + HCl (Violent reaction forming white fumes due to HCl)
      - 4i) Acyl Chloride + Ammonia -> Primary Amide + Ammonium Chloride
      - 4ii) Acyl Chloride + Primary Amide -> Secondary Amide + AlkylAmmonium Salt
      - Ammonia and amines can act as nucleophiles by donating lone pair of electrons on nitrogen
      - Primary Amide- Nitrogen attached to 1 carbon Secondary Amide- Nitrogen attached to 2 carbons