Skip to content
Related Articles
Open in App
Not now

Related Articles

Ferrous Oxalate Formula

Improve Article
Save Article
  • Last Updated : 11 Oct, 2022
Improve Article
Save Article

Ferrous oxalate, or iron (II) oxalate, is a derivative of Oxalic Acid. It is an inorganic compound whose chemical formula is FeC2O4. It is a chemical compound composed of one iron (II) ion (Fe2+) and one oxalate ion (C2O42-). The IUPAC Name of ferrous oxalate is iron (II) oxalate. It is an odorless yellow solid whose molar mass is 143.86 g/mol. It is poorly soluble in water and is soluble in acids. It is used in the metal treatment industry, photo developers’ formulations, and the textile industry. Ferrous oxalate is most commonly encountered in its dihydrate form, i.e., FeC2O4·2H2O. The dihydrate of ferrous oxalate is a coordination polymer that consists of chains of oxalate-bridged ferrous centers, each capped by water molecules. When heated, it dehydrates and decomposes into iron oxides and a pyrophoric black iron, and it also evolves carbon dioxide and carbon monoxide gases. Ferrous oxalate is used for decorative glassware, as a pigment for plastics, paints, and lacquers, in the metal treatment industry, in photo developers’ formulations, and the textile industry.

Structure of Ferrous Oxalate

The molecular formula of ferrous oxalate is FeC2O4 or C2FeO4, and its Canonical SMILES form is C(=O)(C(=O)[O-])[O-].[Fe+2].

Structure of Ferrous Oxalate

Structure of Ferrous Oxalate

Preparation of Ferrous Oxalate

  • Ferrous oxalate can be prepared by the interaction of solutions of ferrous sulfate and sodium oxalate.

FeSO4 + Na2C2O4 → FeC2O4 + Na2SO4

  • A yellow precipitate of ferrous oxalate is formed when oxalic acid is added to a mixture of ferrous ammonium sulfate in water and acidified with 2M sulfuric acid.
  • It can also be manufactured by neutralizing oxalic acid with ferrous hydroxide.
  • When iron reacts with oxalic acid and water, it produces dihydrate iron (II) oxalate and hydrogen.

Fe + H2C2O4 + 2H2O → FeC2O4•2H2O + H2

Physical Properties of Ferrous Oxalate

Chemical Formula  

FeC2O4 (anhydrous) 

FeC2O4 · 2H2O (dihydrate)

IUPAC Name  Iron (II) oxalate 
Molar mass  143.86 g/mol (anhydrous)
179.89 g/mol (dihydrate)
Density  2.28 g/cm3
Appearance  yellow powder
Odour  odorless
Melting point 

190 °C (anhydrous)

150–160 °C (dihydrate)

Boiling point  365.1 °C (anhydrous)
Solubility  Poorly soluble in water and soluble in acids 

Chemical Properties of Ferrous Oxalate

  • When heated, ferrous oxalate decomposes to produce iron (II) oxide, carbon dioxide, and carbon monoxide.

FeC2O4 → FeO + CO2 + CO 

  • When ferrous oxalate reacts with acidified potassium permanganate (KMnO4), KMnO4 oxidizes ferrous oxalate.

10FeC2O4 + 6KMnO4 + 24H2SO4 → 3K2SO4 + 6MnSO4 + 5Fe2(SO4)3 + 24H2O + 10CO2

Uses of Ferrous Oxalate

  • Ferrous oxalate is used as a photographic developer for silver bromide-gelatin plates.
  • It is used to impart a greenish-brown tint to optical glass (like sunglasses, windshields, and railroad car windows).
  • It is used in the metal treatment industry and the textile industry.
  • It is also used as a glass tint (sunglasses and windshields) and as a pigment for plastics, paints, and lacquers.

Hazards

  • Ferrous oxalate is a toxic inorganic compound that evolves carbon monoxide on heating.
  • It may irritate the nose and throat if inhaled. 
  • It causes burning pain in the throat and stomach if swallowed; the mucous membrane may turn white; and it can also cause vomiting, a weak pulse, collapse, and death.
  • Prolonged contact may irritate the skin, and its dust irritates the eyes.

FAQs on Ferrous Oxalate Formula

Question 1: What is ferrous oxalate?

Answer: 

Ferrous oxalate, or iron (II) oxalate, is a derivative of Oxalic Acid. It is an inorganic compound whose chemical formula is FeC2O4. It is a chemical compound composed of one iron (II) ion (Fe2+) and one oxalate ion (C2O42-). The IUPAC Name of ferrous oxalate is iron (II) oxalate. Ferrous oxalate is most commonly encountered in its dihydrate form, i.e., FeC2O4·2H2O.

Question 2: How is ferrous oxalate prepared?

Answer: 

  • Ferrous oxalate can be prepared by the interaction of solutions of ferrous sulfate and sodium oxalate.

FeSO4 + Na2C2O4 → FeC2O4 + Na2SO4

  • A yellow precipitate of ferrous oxalate is formed when oxalic acid is added to a mixture of ferrous ammonium sulfate in water and acidified with 2M sulfuric acid.

Question 3: What happens when ferrous oxalate reacts with acidified potassium permanganate?

Answer: 

We know that potassium permanganate in an acidic medium act as a strong oxidizing agent. When ferrous oxalate reacts with acidified potassium permanganate (KMnO4), KMnO4 oxidizes ferrous oxalate.

10FeC2O4 + 6KMnO4 + 24H2SO4 → 3K2SO4 + 6MnSO4 + 5Fe2(SO4)3 + 24H2O + 10CO2

Question 4: Mention some properties of ferrous oxalate.

Answer: 

Ferrous oxalate or iron (II) oxalate is an odorless yellow solid whose chemical formula is FeC2O4. It is poorly soluble in water and is soluble in acids. Its molar mass is 143.86 g/mol and its melting point is 190 °C.

Question 5: What are the uses of ferrous oxalate?

Answer:

Ferrous oxalate is used as a photographic developer for silver bromide-gelatin plates. It is used to impart a greenish-brown tint to optical glass (like sunglasses, windshields, and railroad car windows). It is used in the metal treatment industry and the textile industry. It is also used as a glass tint (sunglasses and windshields) and as a pigment for plastics, paints, and lacquers.

Question 6: Mention some hazards of ferrous oxalate.

Answer:

Ferrous oxalate is a toxic inorganic compound that evolves carbon monoxide on heating. It may irritate the nose and throat if inhaled. It causes burning pain in the throat and stomach if swallowed; the mucous membrane may turn white; and it can also cause vomiting, a weak pulse, collapse, and death. Prolonged contact may irritate the skin, and its dust irritates the eyes.

My Personal Notes arrow_drop_up
Related Articles

Start Your Coding Journey Now!