Ammonium Ferrous Sulphate

Ammonium ferrous sulphate, more commonly known as Mohr's salt, is a fascinating inorganic compound with a range of applications, particularly in chemistry. Here's a more detailed look:

Chemical Composition and Properties:

• Formula: (NH₄)₂Fe(SO₄)₂·6H₂O (hexahydrate)
• This formula indicates it's a double salt, meaning it contains two different cations (ammonium and iron(II)) and a common anion (sulfate).
• It exists as light green, crystalline solid.
• It's soluble in water, forming a slightly acidic solution.
• A key characteristic of Mohr's salt is its resistance to oxidation in air, which makes it a valuable reagent. This stability is superior to that of ferrous sulfate.

Key Features and Applications:

• Laboratory Reagent:
  • Mohr's salt is widely used in analytical chemistry, especially in titration, as a reliable source of ferrous (Fe²⁺) ions. 
  • Its stability makes it easier to handle and store compared to other iron(II) salts.

• Redox Reactions:
  • It plays a crucial role in redox titrations, where it acts as a reducing agent.
• Other Applications:
  • It has applications in various chemical syntheses.
  • It is used in Gel dosimetry to measure high doses of gamma rays.
  • It has uses in metallurgy.

Why is it stable?

• The presence of ammonium sulfate contributes to its stability. The slightly acidic nature of its solutions helps to inhibit the oxidation of Fe²⁺ to Fe³⁺.

In summary:

Mohr's salt is a valuable chemical compound due to its stability, making it a preferred choice in various laboratory and industrial applications, especially where a reliable source of ferrous ions is needed.