Ferrous Sulphate

Introduction

Ferrous sulphate or Iron (II) sulphate is the salt of the metal Iron and has a chemical formula FeSO₄. Its main use is for the treatment of patients suffering from anaemia, Iron deficiency.

The reactions of iron with sulphuric acid result in the formation of some salt. Further studies identified the two salts that had been formed by the reaction. The salt formed is ferrous sulphate and ferric sulphate. The appearance of ferrous sulphate is in a way that it has a greenish appearance, so it is named green vitriol. Both these salts have several industrial applications. Even though it has only differences in their oxidation state, their uses of them are different. Ferrous sulphate FeSO₄ is used in the manufacture of inks, pesticides, fertilizer, etc. Ferric sulphate is used in the production of iron alums, sewage treatment, etc.

What Is Ferrous Sulphate?

Iron (II) sulphate or Ferrous sulphate is an important salt of the metal, Iron. It is a white-coloured powder with no odour. Many hydrated forms of this compound are present. The general formula for a hydrated form of this salt is FeSO₄.nH₂ O. The monohydrate, FeSO₄.H₂ O the form of Ferrous sulphate is a relatively rare one and is called Szomolnokite. Among the hydrates heptahydrate, FeSO₄.7H₂ O

It is the most known. And has a crystalline blue-green coloured appearance so it is also called green vitriol. The hepta hydrated form of ferrous sulphate is very common and has a wide application. The paramagnetic complex of iron is formed by the dissolution of iron sulphate in water and is Fe[H₂ O]₆²⁺ and has an octahedral geometry.

The name Copperas is also given to this salt because it prepares which copper sulphate. It is a safe and efficient medicine for the treatment of iron deficiency and is included in the list of medicines in the WHO.

Ferrous Sulphate Structure − FeSO₄

Ferrous sulphate contains Fe²⁺ and SO₄^2- ions. Ferrous sulphate contains covalently bonded two units and four hydrogen bond acceptors. The structure of FeSO₄ is

Physical Properties of Ferrous Sulphate-FeSO₄

Some of the properties of ferrous sulphate are tabulated below.

Ferrous sulphate	FeSO4
Molar mass	151.91 g/mol
Colour	White coloured crystal
Solubility in alcohol	Negligible
Solubility in water	Soluble
Density	3.65cm3
Melting point	680 °C
Refractive index	1.591
Odour	Odourless

Ferrous Sulphate Production

Many methods can be adopted for the preparation of ferrous sulphate. The reaction of copper sulphate with iron results in the formation of iron sulphate and the reaction is a displacement reaction.

$$\mathrm{Fe+CuSO_4→FeSO_4+ Cu}$$

In the manufacturing process of steel, it is allowed in a sulphuric acid bath before its processing. A particular amount of ferrous sulphate is produced during this process with the evolution of hydrogen gas. The reaction is,

$$\mathrm{Fe+H_2 SO_4→FeSO_4+ H_2}$$

Another method to produce ferrous sulphate is the oxidation of pyrite. Sulphuric acid is also obtained acid as a by-product of this reaction.

$$\mathrm{2FeS_2+7O_2+2H_2 O→2FeSO_4+2H_2 SO_4}$$

Reactions

Ferrous sulphate is an important reducing agent. The reaction of ferrous sulphate with Nitric acid results in the formation of Nitrogen oxide.

$$\mathrm{FeSO_4 +H_2 SO_4+HNO_3→Fe_2 (SO_4 )^{3+}+H_2 O+NO}$$

It will convert chlorine gas to chloride. The reaction is,

$$\mathrm{FeSO_4+Cl_2→Fe_2 (SO_4 )^{3+}+FeCl_3}$$

As we know ferrous sulphate is commonly available in its hepta hydrate form, so the heating results in the removal of a water molecule first. And then a reddish brown-coloured ferric oxide will form. Sulphur dioxide, SO₂ and Sulphur trioxide, SO₃ are also obtained as a byproduct. The reaction is,

$$\mathrm{FeSO_4·7H_2 O→FeSO_4+7H_2 O}$$

$$\mathrm{2FeSO_4→Fe_2 O_3+SO_2+SO_3}$$

Uses

The use of ferrous sulphate is very wide. Some of the uses of ferrous sulphate are pointed out below.

• Ferrous sulphate is used as a colorant in ink manufacture and textile industries.

• It is also used as a colour in the food industry.

• Ferrous sulphate has a rich source of iron, so it is used in the medicinal industry for the production of iron tablets for treating iron deficiency.

• It is useful for plant growth and development since it is applied to the soil with a lowering pH of soils.

• It is used in sewage water treatment since it is very effective in the clarification and dewatering of sewage water.

• For the collodion process images, Ferrous sulphate is used as a photographic developer.

• For the identification of mushrooms, it is used as a reagent.

• For giving colour to constructions and limestone’s it is used.

• For colouring wood ferrous sulphate is used.

Conclusion

Ferrous sulphate is an important salt of the metal iron. There are several hydrated forms of this salt. Of which the hepta hydrated form of ferrous sulphate is very important. The application of iron sulphate is very wide it is commonly used for the disease anaemia to treat the deficiency of iron. Iron and sulphate ions. Several methods can be adopted for the preparation of ferrous sulphate. It can be produced by the reaction of iron with sulphuric acid and by the reaction of copper sulphate with iron. The anhydrous form of ferrous sulphate is colourless and has no odour.

FAQs

1. What will happen when one consumes Ferrous sulphate excessively?

The excess consumption of ferrous sulphate causes problems mainly in the stomach region. It will result in vomiting, diarrhoea, gastrointestinal distress, stomach-ache, etc. So, care must be taken before taking ferrous sulphate.

2. Who should not take ferrous sulphate?

Children with age, less than twelve cannot consume Ferrous sulphate tablets. And if one is taking Ferrous sulphate take necessary precautions not to take antacids or antibiotics.

3. Is Ferrous sulphate basic or acidic?

Ferrous sulphate is an acidic salt since it is made up of strong acid and a weak base. And so, it will turn blue litmus to red.

4. What is the colour of ferrous sulphate in the heptahydrate form after decomposition reaction?

Hepta hydrated form of ferrous sulphate losses the seven water molecules present on them during the decomposition reaction. And there it will further result in the colour change of heptahydrate from blue-green to white.

5. Why is metal iron essential for the human body?

Iron is an essential metal in our body for its proper development and growth. It is present in haemoglobin which is the oxygen transporter present in red blood cells. And it is present in myoglobin which is an oxygen storage muscle present in our body. So, for blood production, Iron is very essential. Also, to produce some hormones.