Ethanoic acid is commonly called as acetic acid. 5-8% solution of acetic acid in water is called vinegar and is used widely as preservative in pickles.

Chemical Reactions

Acidity:

(Reaction with metals and alkalies)

  1. Ethanoic acid reacts with active metals like Na to liberate hydrogen. This reaction is similar to that of ethanol.
  2. Ethanoic acid reacts with NaOH to form sodium acetate and water.
  3. Ethanoic acid reacts with sodium carbonate and sodium hydrogen carbonate which are weaker bases and liberates CO2.

    4. The strength of acids may be expressed in terms of their pKa values.

    4) Esterification Reactions

    1. What are esters?

    Esters contain the functional group

    The general formula is R – COO - R/ . R and R/ are alkyl groups or phenyl groups.

    Activity 2

    Take 1 ml of ethanol (absolute alcohol) and 1ml of glacial acetic acid along with a few drops of concentrated sulphuric acid in a test tube.

    Warm it in a water-bath or a beaker containing water for at least five minutes as shown in Fig. Pour the warm contents into a beaker containing 20-50 ml of water and observe the odour of the resulting mixture.

    You will notice that the resulting mixture is a sweet odoured substance. This substance is nothing but ethyl acetate, an ester. The reaction in activity – 2 is called esterification reaction.



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