3.3.9.1 Carboxylic acids and esters (A-level only)

• Solubility in COOH

  Reduced in length of insoluble R chain
• Metal + acid

  Salt + hydrogen
• Acid + Alkali

  Salt + water
• Salt + carbonates

  Salt + water + carbon dioxide
• Why are COOH weak

  They partially ionise in solution less H+ ions
• Product of carbonyl and HCN

  Hydroxylnitrile
• Ethanoic acid + NH3

  Ammonium ethanoate
• Butanoic acid + Mg

  Magnesium butanoate
• Uses of esters

  Flavorings, perfumes, solvents and plasticisers
• What is esterficiatiin

  Alcohols + COOH = ester
• Alcohol + COOH

  ester
• Esterification

  Concentrated H2SO4, reflux, and ester is the product
• Propanoic acid + methanol

  Methyl propanoate
• What can you use to break down an ester?

  Water, hydrolysis
• Ester + water (and what does it need)

  Alcohol + COOH, catalyst
• Names of different catalyst

  Acid or alkaline
• Acid hydrolysis of esters (regent, product, conditions)

  Uses water in acid conditions, dilute sulphuric acid, COOH + OH, reflux
• Alkaline hydrolysis of ester (reagent, conditions, product)

  Uses water in alkaline conditions, dilute NaOH, reflux, carboxylate ion/salt and alcohol
• Uses of carboxylate

  Soaps and detergents
• Propyl methanoate

  Methanoic acid + propanol
• Fats are solids

  Higher melting point, chains packed closely together, stronger VDW, packed efficiently, saturated, if MP above RT fat
• Oils are liquids

  Unsaturated, lower boiling point, chains are bent so don't pack as closely, weaker VDW, has E/Z isomerism
• Triesters can by alkaline hydrolysis split up to make

  Give alcohol and sodium salts of COOH called soaponification
• Why does ethanoic acid react more slowly than HCI


  H+ is more lower in ethanoic acid, lower frequency of effective collisions
• How can you make biodiseal

  Lipids
• Use of KOH in the biodisel

  Acts a catalyst
• ester + HCI

  COOH + salt
• What product is distilled off

  glycerol
• What product doesn't distill from the flask

  soap
• What can lipids make

  Biodiseal and soap