Ethanoic Acid

What is Ethanoic Acid?

Ethanoic acid (CH3COOH) belongs to the group of carboxylic acids and is commonly called as acetic acid. It is slightly heavier than water with a density of 1.05 g/cm3. After adding 5-8% of acetic acid in water it becomes vinegar and is mostly used as preservatives in pickles. Acetic acid is the common name for Ethanoic acid.

Properties of Acetic acid

Chemical formula CH3COOH
Molecular Weight/ Molar Mass 60.05 g/mol
Density 1.05 g/cm3
Boiling Point 118oC
Melting Point 16oC

Acetic Acid structure:

Ethanoic Acid

What is glacial acetic acid?

Ethanoic acid is also referred to as glacial acetic acid because its melting point is 16oC.

Hence it often freezes in the winter season when the climate is cold.

Reactions of ethanoic acids:

  • Esterification reaction:

  • When carboxylic acid and alcohol react, the product formed is known as an ester. Below is an example of the formation of an ester from the reaction of ethanoic acid with absolute ethanol in the presence of an acid as a catalyst.
  • CH3COOH     +      CH3CH2OH      \(\rightarrow\)     CH3COOCH2CH3
  • (Ethanoic acid) (Ethanol) (Esters)
  • Esters have a sweet fruity smell. They are mainly used for making perfumes and synthetic flavoring agents. The reaction of esters with alkalis gives carboxylic acid salt and alcohol. This reaction is used in the making of soaps and the process is called as saponification reaction.
  • CH3COOC2H5      + NaOH      \(\rightarrow\)         C2H5OH +  CH3COONa
  • Reaction with a base:

  • Ethanoic acid reacts with a base to give the salt and water just like other mineral acids.
  • Reaction with carbonates and hydrogen carbonates:

  • Carbon dioxide, salt, and water are produced when ethanoic acid reacts with carbonates and hydrogen carbonates. Sodium acetate is usually produced as a salt when ethanoic acid reacts with sodium bicarbonate as shown in the reaction below:

CH3COOH  +  NaHCO3     \(\rightarrow\)      CH3COONa + H2O + CO2

Uses of Acetic Acid

  1. Ethanoic acid is widely used in many industries.
  2. Commercially it is used in the manufacturing of esters, vinegar, and many polymeric materials.
  3. Vinegar has been shown to reduce high concentrations of blood sugar.
  4. Used as an agent to lyse red blood cells before white blood cells are examined.
  5. Used as a solvent in the production of camphor, ascent and cooking ingredient.
  6. Used as a stop bath for photographic emulsion development.
  7. Farmers sometimes spray acetic acid on livestock silage to fight fungal and bacterial growth.

Learn more about the chemical behavior and importance of ethanoic acid with the expert faculties at Byju’s.

Practise This Question

The reaction 2Na + 2CH3CH2OH    2CH3CH2ONa+ + H2 suggests that ethanol is