Carboxylic Acids

Cards (12)

  • Carboxylic acids have the functional group COOH
  • carboxylic acid names all end in 'anoic acid'. For example methanoic acid
  • COOH group should always go at the end
  • Carboxylic acids are all weak acids. This means they don't fully ionise.
  • We show their ionisation with equations like the one below. With an equilibrium acid between the left full acid, and the ionised version where it's lost its hydrogen on the right. The negative ions formed in ionisation are called 'anoates'. For example like below, propanoic acid will form a propanoate ion and a hydrogen ion.
  • If we react a carboxylic acid with a metal carbonate it will form a salt, water and carbon dioxide. For example: Ethanoic acid + potassium carbonate ---> potassium ethanoate + water + carbon dioxide.
  • Carboxylic acids are made by taking an alcohol and oxidising it using an oxidising agent.
  • carboxylic acids are a homologous series
  • Carboxylic acids are a homologous series. They are basically alkane chains with a COOH group on one end.
    1. All carboxylic acids are weak acids. Weak acids do not fully ionise in water. This means that weak acids don't release all their hydrogen ions.
    1. The ionisation of carboxylic acids in water can be shown as an equilibrium reaction like this:
    C3H7COOH ⇌ C3H7COO- + H+ 
    1. It is always the H+ attached to the OH group that ionises. The other hydrogen atoms are strongly bonded to the carbon atoms.
    1. Carboxylic acid + metal ➔ salt + hydrogen
    2. Carboxylic acid + metal oxide ➔ salt + water
    3. Carboxylic acid + metal hydroxide ➔ salt + water
    4. Carboxylic acid + metal carbonate ➔ salt + water + carbon dioxide