Chemical Properties of Carboxylic Acid


Preparation of ethanoic acid in the laboratory

  • Oxidation of ethanol
    • Ethanol is oxidised by acidified potassium dichromate(VI) solution.
    • Dichromate ion (orange) changes to chromium ion (green). 
\(C_2H_5OH(l) \xrightarrow[]{[O]} CH_3COOH (l)\)


Chemical reactions of ethanoic acid as an acid

  • Reaction with base or alkali
    • Product: salt and water
    • Also known as neutralisation reaction.
    • Example of reaction with sodium hydroxide;
\(CH_3COOH (aq) + NaOH(aq) \rightarrow CH_3COONa (aq) + H_2O(l)\)


  • Reaction with reactive metal
    • Product: salt and hydrogen gas  
    • Example of reaction with magnesium;
\(2CH_3COOH (aq) + Mg(s) \rightarrow (CH_3COO)_2Mg (aq) + H_2(g)\)


  • Reaction with metal carbonate
    • Product: salt, carbon dioxide gas and water
    • Example of reaction with calcium carbonate;
\(2CH_3COOH (aq) + CaCO_3(s) \rightarrow (CH_3COO)_2Ca(aq) + H_2O(l) + CO_2(g)\)


The chemical reaction of ethanoic acid with an alcohol

  • Product: ester
  • Also known as an esterification reaction.
  • Catalyst: hydrogen ion
\(CH_3COOH (aq) + C_2H_5OH(l) \xrightarrow []{H^+}CH_3COOC_2H_5(aq) + H_2O(l) \)