Vitriol - Chemical Compound

What is Vitriol?

Vitriol is the common name of sulphate. The sulphate ion was previously called vitriol. So, Vitriol is the generic term for a class of chemical compounds made up of sulphates of some metals, such as iron or copper. Sulphate is known as vitriol, which is an old name for it. Copperas and green vitriol, the blue-green heptahydrate, have been known since ancient times (hydrate with 7 molecules of water) as the most common form of this material. The colour of these mineral elements, such as green vitriol for hydrated iron(II) sulphate and blue vitriol for hydrated copper(II) sulphate, distinguishes them.

There are three types of vitriol occurring. Let us see these three types of vitriol in detail:

1. Green vitriol

2. Red vitriol

3. White vitriol 


Green Vitriol

Iron(II) sulfate or ferrous sulphate denotes a range of salts with the formula FeSO4·xH2O. These compounds exist mostly in hydrated form. Ferrous sulphate is commonly found as the heptahydrate (7 molecules of water of hydration is present) form. So, the value of x in this compound is 7. But the value of x is not fixed, it can alter depending upon the condition of temperature and pressure. 


Green Vitriol Structure

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As we know that the green vitriol chemical name is ferrous sulphate, therefore, in its structure one atom of iron is present. This iron atom exists in a +2 oxidation state in the green vitriol compound. The ferrous atom is attracted to the sulphate by the strong electrostatic force of attraction. In the green vitriol molecule, seven water molecules surround the ferrous sulphate. Six water molecules surround the iron atom while the other one surrounds the sulphate ion. Some water molecules are attracted by the dative or coordinate bond with the atom and some water molecules are attracted by the help of hydrogen bonding. All the iron (II) sulphates dissolve in water to give the same aquo complex [Fe(H2O)6]2+. This complex has octahedral molecular geometry. The green vitriol complex is paramagnetic in nature.


Properties of Green Vitriol


Physical Properties of Green Vitriol

  • Green vitriol is an odourless compound.

  • The appearance of the green vitriol is Bluish-green in colour.

  • Green vitriol exists in both powder and crystals forms.

  • The covalently bonded unit in green vitriol is 2.

  • The hydrogen bond acceptor capacity of the green vitriol is 4.

  • The solubility of green vitriol in water is high. It can easily dissolve in water.

Chemical Properties of Green Vitriol

1. Ferrous sulfate (green vitriol) gives a reaction with aluminium. This reaction is a type of displacement reaction. In this reaction, aluminium sulfate and metallic iron are formed. The displacement chemical reaction is given below.

2Al + 3FeSO4 → Al2(SO4)3 + 3Fe

2. Ferrous sulfate (green vitriol) gives a reaction with the potassium permanganate compound in the presence of concentrated sulphuric acid. In this reaction, ferric sulfate, manganese sulfate, potassium sulfate, and water are formed as a product.

10FeSO4 + 2KMnO4 + 8H2SO4 → 5Fe2(SO4)3 + 2MnSO4 + 8H2O + K2SO4


Green Vitriol Uses

  • The hydrated form is used medically to treat iron deficiency.

  • Green vitriol is also used for industrial applications. 

  • It is used in prophylaxis for iron deficiency in pregnancy and treatment of iron deficiency anaemia.

  • If sedation or general anaesthesia is needed, this medication is used as a precaution to avoid a hypotensive episode.

  • Chlorine can also be used for ferrous sulphate. Chlorinated copperas treatment is the common name for this treatment.

Red Vitriol

Red vitriol is cobalt (II) sulphate heptahydrate. When red vitriol is heated at high temperature, red vitriol gets converted into their oxide form and gives off their water of hydration molecules along with sulphur trioxide which then combines to form sulphuric acid. The red vitriol formula is CoSO4 . 7H2O.


Red Vitriol Structure

As we know that the red vitriol chemical name is cobalt sulphate, therefore, in its structure one atom of cobalt is present. This cobalt atom exists in a +2 oxidation state in the red vitriol compound. The cobalt atom is attracted to the sulphate by the strong electrostatic force of attraction. In red vitriol molecules, seven water molecules surround the ferrous sulphate. Six water molecules surround the cobalt atom while the other one surrounds the sulphate ion. Some water molecules are attracted by the dative or coordinate bond with the atom and some water molecules are attracted by the help of hydrogen bonding. All the cobalt (II) sulphates molecules dissolve in water to give the same aquo complex [Co (H2O)6]2+. This complex has octahedral molecular geometry. The red vitriol complex is paramagnetic in nature.

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Properties of Red Vitriol


Physical Properties of Vitriol

  • Red vitriol is an odourless compound.

  • Red vitriol is completely soluble in water. This high solubility is due to the presence of large numbers of water molecules.

  • Red vitriol is paramagnetic in nature. As it contains unpaired electrons in its orbitals.

  • Red vitriol is soluble in methanol.

  • The appearance of red vitriol is fleshy red.

  • Red vitriol exists in both crystalline form and powdered form.

Chemical Properties of Red Vitriol

At room temperature, the cobalt sulphate heptahydrate is only stable at high humidity levels (>70%). It is transformed to the hexahydrate form in all other circumstances. At 100 and 250 degrees Celsius, the hexahydrate form of cobalt sulphate is converted to the monohydrate and anhydrous forms, respectively.

CoSO4(H2O)7 → CoSO4(H2O)6 + H2O

CoSO4(H2O)6 → CoSO4(H2O) + 5 H2O

CoSO4(H2O) → CoSO4 + H2O


Red Vitriol Uses

  • Cobalt sulphates are essential intermediates in the cobalt extraction process.

  • Cobalt sulphate is crushed, and partially processed ores are treated with sulfuric acid to produce red-coloured cobalt sulphate solutions.

  • Hydrated cobalt (II) sulphate is a cobalt salt that is used in the production of pigments and other cobalt salts.

  • Porcelain and glass contain cobalt sulphate pigment. 

  • Cobalt(II) sulphate (red vitriol) is used in storage batteries.

  • Red vitriol is used in electroplating baths.

  • Red vitriol is used in sympathetic inks, soil, and animal feed additives. For these motives, cobalt sulphate or white vitriol is made by reacting cobalt oxide with sulfuric acid.

  • The heptahydrate is a popular source of cobalt in coordination chemistry since it is commercially available.


White Vitriol

White vitriol chemical name is zinc sulphate. Zinc sulphate (ZnSo4) molecule is an inorganic compound consisting of zinc ion and sulphate ion. The molecular formula of white vitriol is ZnSO4. Historically,  ZnSO4 was known as "white vitriol". White vitriol is on the World Health Organization's List of Essential Medicines. This list includes the most important medications needed in a basic health system. Zinc sulphate molecules in an anhydrous state are colourless crystalline solid. Zinc sulphate molecule is also present in two forms: hexahydrated form (ZnSO4.6H2O) and heptahydrate form (ZnSO4.7H2O) forms. In water, all forms are soluble. They're all noncombustible. It causes the most dangerous threat to the climate. To prevent white vitriol from spreading to the environment, instant action should be taken. It is used to make rayon, as well as a feed supplement and fertiliser ingredient.


Structure of White Vitriol

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In the structure of the zinc sulphate molecule, one ion of zinc is present. This zinc ion is attracted by the strong electrostatic force of attraction between zinc ion and sulphate ion. In the white vitriol molecule, seven water molecules are present. Some water molecules are attracted to the zinc ion with the help of coordinate bonds and the other water molecules are attracted by the hydrogen bonding.


Properties of White Vitriol


Physical Properties of White Vitriol

  • White vitriol is an odourless compound.

  • White vitriol is soluble in water.

  • White vitriol is a non combustible substance.

  • It occurs in both amorphous form and crystalline pellets form.

  • These are hygroscopic.

  • The melting point of white vitriol is 680 degrees celsius.

  • The density of white vitriol is 3.8 g/cm3.

Chemical Properties of White Vitriol

  • The cloudiness of white vitriol is a common occurrence. This is due to the isolation of the basic salt that is formed as a result of partial hydrolysis.

  • It releases harmful sulphur oxides and zinc oxide fumes when heated to decomposition.

  • The powdered form and granular form of white vitriol lose water to the atmosphere. This phenomenon takes place at a higher temperature around more than 238 degrees celsius.

  • The solution of white vitriol is acidic in nature.

  • White vitriol is insoluble in alcohol.

Uses of White Vitriol

  • White vitriol is used for the synthesis of human drugs.

  • White vitriol is used in making cosmetic products.

  • White vitriol is used in oral care products.

  • It acts as an antimicrobial and antiplaque agent.

  • White vitriol is used in the synthesis of the antibacterial drug.

  • It is used as an absorbent. Therefore, used in making substances for soaking up liquid.

  • White vitriol is used as a general adhesive and binding agent. 

Other Types of Vitriol

Other than white vitriol, red vitriol, and white vitriol there are many more types of vitriol. Let us discuss these vitriols in short.

  1. Sweet Oil of Vitriol- Diethyl Ether

  2. Vitriol of Argile- This type of vitriol is also known as vitriol of clay. Chemical name of this type of vitriol is aluminium sulphate.

  3. Vitriol of Mars- The chemical name of vitriol of mars is ferric sulphate (Iron (II) sulphate).

  4. Blue Vitriol- Chemical name of blue vitriol is copper sulphate.

  5. Black Vitriol- It is a mixture of copper, magnesium, iron, manganese, cobalt, and nickel hydrated sulphate.


Did You Know That?

  • The World Health Organization lists green vitriol as an important medicine. It is regarded as one of the safest and most effective medicines available in the healthcare system. With over 8 million prescriptions written in 2018, it was the 94th most widely prescribed drug in the United States.

  • Sulphuric acid is known as the oil of vitriol.

  • Since it dissolved almost all substances except gold, vitriol became extremely essential in alchemy.

FAQs (Frequently Asked Questions)

Question: What is White Vitriol?

Answer: Zinc sulphate is the chemical term for white vitriol. Zinc sulphate, also known as "white vitriol," is an inorganic compound with the formula ZnSO4. It is on the WHO's List of Essential Medicines, which is a list of the most necessary drugs required in a general health system. Anhydrous zinc sulphate is a colourless crystalline solid. Hexahydrate (ZnSO4.6H2O) and heptahydrate (ZnSO4.7H2O) zinc sulphate are also available. All forms are soluble in water. All of them are noncombustible. The greatest risk is the threat to the environment. Immediate action is needed to prevent it from spreading to the community. It's used in the production of rayon as well as as a feed supplement and fertiliser ingredient.

Question: What is Red Vitriol? Give its Uses.

Answer: Cobalt (II) sulphate heptahydrate is red vitriol. As red vitriol is heated to a high temperature, it is converted to its oxide form, which releases its water of hydration molecules as well as sulphur trioxide, which combine to form sulphuric acid. CoSO4. 7H2O is the formula for red vitriol.

The uses of red vitriol are given below:

  • In the cobalt extraction process, cobalt sulphates are required intermediates.

  • To make red-coloured cobalt sulphate solutions, cobalt sulphate is crushed and partially processed ores are treated with sulfuric acid.

  • Cobalt salts including hydrated cobalt (II) sulphate are used to make pigments and other cobalt salts.

  • Cobalt sulphate pigment is used in porcelain and glass.

  • Cobalt(II) sulphate (red vitriol) is used in storage batteries, electroplating processes, security inks, and soil and animal feed supplements. For these motives, red vitriol is made by reacting cobalt oxide with sulfuric acid.

  • Since it is commercially available, the heptahydrate is a common source of cobalt in coordination chemistry.