MANGANESE SULFATE (MNSO4): STRUCTURE, PROPERTIES, OBTAINING, USES - CHEMISTRY - 2025

The manganese sulfate (II) is an inorganic solid formed by the elements manganese (Mn), sulfur (S) and oxygen (O). Its chemical formula is MnSO ₄. Its anhydrous form (without water in its structure) is a white solid. However, it has several hydrated forms and all of them are pinkish solids.

Manganese sulfate in very small (minute) amounts is used as a micronutrient for both animals and humans, as it is required for the normal functioning of the body.

Anhydrous manganese sulfate MnSO ₄. YOSF0113 at English Wikipedia / Public domain. Source: Wikimedia Commons.

It is also added together with certain fertilizers in soils deficient in manganese (Mn) for agricultural crops that need it, such as grape plants.

Due to the pink coloration of its hydrated varieties, it is used in pigments that are used to paint ceramics, color fabrics and other materials. It also serves to obtain other manganese compounds.

MnSO ₄ must be handled with care. Inhalation can cause respiratory problems and cause serious disturbances to the nervous system, including symptoms similar to Parkinson's disease.

Its excess can also cause damage to terrestrial and aquatic animals and plants.

Structure

Anhydrous manganese sulfate (without water in its crystalline structure) is formed by a manganese ion in oxidation state +2, that is, Mn ²⁺ and a sulfate anion SO ₄ ^2-.

Chemical structure of manganese sulfate MnSO ₄. Author: Marilú Stea.

Nomenclature

• Manganese (II) sulfate
• Manganese monosulfate
• Anhydrous Manganese Sulfate MnSO ₄
• Manganese sulfate monohydrate MnSO _{4 •} H ₂ O
• Manganese sulfate tetrahydrate MnSO _{4 •} 4H ₂ O
• Manganese sulfate pentahydrate MnSO _{4 •} 5H ₂ O
• Manganese sulfate heptahydrate MnSO _{4 •} 7H ₂ O

Properties

Physical state

Anhydrous MnSO ₄ (without water in its structure) is a white crystalline solid. However, the hydrated varieties are solid pink or pale red.

Manganese Sulfate Tetrahydrate MnSO ₄.4H ₂ O is a pink solid. Benjah-bmm27 / Public domain. Source: Wikimedia Commons.

Molecular weight

MnSO ₄ = 151 g / mol

MnSO _{4 •} H ₂ O = 169.02 g / mol

Melting point

Anhydrous MnSO ₄ = 700 ºC

Monohydrate MnSO _{4 •} H ₂ O = 400-450 ° C

Tetrahydrate MnSO _{4 •} 4H ₂ O = 30 ° C

Boiling point

Anhydrous MnSO ₄ = decomposes at 850 ° C.

Tetrahydrate MnSO _{4 •} 4H ₂ O = 850 ° C

Density

MnSO ₄ = 3.25 g / cm ³

MnSO _{4 •} H ₂ O = 2.95 g / cm ³

Solubility

Very soluble in water: 52 g / 100 mL of water at 5 ° C. Soluble in alcohol. Insoluble in ether. Slightly soluble in methanol.

pH

A 5% MnSO _{4 •} H ₂ O solution has a pH of 3.7.

Chemical properties

When dissolved in water, MnSO4 separates into its Mn ²⁺ and SO ₄ ^2- ions.

The manganese ion (ii) Mn ²⁺ in acidic or neutral solution is bound to 6 molecules of water H ₂ O forming the hexaacuomanganese ion ²⁺, which is pink in color.

The hexaacuomanganese ion ²⁺ is quite resistant to oxidation. In a basic medium (alkaline pH), said ion becomes manganese hydroxide (ii) Mn (OH) ₂, which is easily oxidized, forming manganese (III) and manganese (IV) compounds.

Acidic MnSO ₄ solutions are pink due to the presence of the hexaacuomanganese ion ²⁺. Author: Steve Cross. Source: Pixabay Manganese sulfate has several hydrated forms, that is, with water H ₂ O in its crystalline structure.

These are the monohydrate MnSO _{4 •} H ₂ O, MnSO tetrahydrate _{4 •} 4H ₂ O, MnSO pentahydrate _{4 •} 5H ₂ O and MnSO heptahydrate _{4 •} 7H ₂ O. These hydrate forms containing the ion hexaacuomanganeso ²⁺ in the crystals and by this reason they are pink solids.

MnSO _{4 •} H ₂ O monohydrate is slightly efflorescent, which means that it loses some of its water of hydration slowly when exposed to the environment.

Obtaining

MnSO ₄ can be obtained by treating manganese (II) oxide MnO, manganous hydroxide Mn (OH) ₂ or manganese (II) carbonate MnCO ₃ with sulfuric acid H ₂ SO ₄.

MnCO ₃ + H ₂ SO ₄ → MnSO ₄ + H ₂ O + CO ₂

Applications

As a nutritional supplement

Manganese sulfate in minute amounts serves certain functions of the human body and animals.

That is why it is important as a useful compound in nutrition and is supplied as a dietary supplement. It is used in traces (extremely small amounts).

High amounts can be very toxic and harmful.

In veterinary medicine

MnSO ₄ is administered to poultry (chickens, turkeys, ducks and pheasants) to prevent deficiency or lack of the element manganese in such animals.

The lack of manganese manifests in them, for example, as the disease called perosis, which is the deformation of the bones of the legs of young birds.

Ducklings may require traces of MnSO ₄ in their diet to prevent perosis. Authors: S. Hermann & F. Richter. Source: Pixabay.

It is applied to the feeding of these birds in very small quantities or traces.

In agriculture

Manganese sulfate is used as a micronutrient in fertilizers for vines (grape plants) and tobacco plantations in manganese-deficient soils.

However, some studies indicate that excess manganese sulfate can inhibit or decrease the formation of certain enzymes important for the growth of plants and their shoots.

In some cases MnSO ₄ is applied to the soil where the grape plants are. Author: Schwoaze. Source: Pixabay.

For example, it has been found to be toxic to some crops such as cotton.

MnSO ₄ also has use in fungicides and together with certain organic compounds it is part of certain pesticides.

In various applications

Hydrated MnSO ₄ is used for its coloration to prepare inorganic pigments that are used in red ceramic varnishes, in fabric printing dyes and other materials.

Manganese sulfate is used in the manufacture of glass and soaps are also made from it.

Some ceramic tiles may contain manganese sulfate pigments. Author: DWilliams. Source: Pixabay.

MnSO ₄ is the starting material to obtain the metal manganese (Mn) electrolytically, that is, by applying electricity to aqueous solutions.

It also makes it possible to obtain manganese dioxide MnO ₂ and manganese carbonate MnCO ₃.

MnSO _{4 is} also used for chemical analysis and in the formulation of solutions that are used in genetic experiments with microorganisms.

Risks

Manganese sulfate contains manganese (II) ion (Mn ²⁺), which can be both harmless and toxic depending on the amounts to which the person, animal or plant is exposed.

Manganese is essential for the normal functioning of the body of humans, animals and some plants. But unfortunately manganese is also neurotoxic, that is, it affects the nervous system and some plant functions.

Apparently safe amounts

MnSO ₄ given with food in trace form (extremely small or minute amounts) is generally considered safe by the Food and Drug Administration, or FDA.

Dangerous quantities

Prolonged or repeated exposure to this compound in appreciable amounts can cause harm to humans and animals.

It causes irritation to the eyes and mucous membranes of the respiratory tract, anorexia, headache, loss of balance, pneumonia and respiratory infections.

Chronic inhalation causes damage to the nervous system, generating manganism, hand tremors and typical symptoms of Parkinson's disease.

Manganese sulfate affects the nervous system. Author: Sabine Zierer. Source: Pixabay.

Therefore, the dispersion of MnSO ₄ dust should be avoided, wear respiratory equipment and protective gloves.

It is toxic to aquatic life and it generates long-term effects. It should be stored in places where there is no access to the drainage system or sewers. It is very important not to allow it to be disposed of in the environment.

References

1. US National Library of Medicine. (2019). Manganese sulfate. Recovered from pubchem.ncbi.nlm.nih.gov.
2. Ullmann's Encyclopedia of Industrial Chemistry. (1990). Fifth Edition. Volume A22. VCH Verlagsgesellschaft mbH.
3. US National Library of Medicine. (2019). Manganese sulfate monohydrate. Recovered from pubchem.ncbi.nlm.nih.gov.
4. Cotton, F. Albert and Wilkinson, Geoffrey. (1980). Advanced Inorganic Chemistry. Fourth Edition. John Wiley & Sons.
5. Dunham, MJ (2010). Guide to Yeast Genetics: Functional Genomics, Proteomics, and Other Systems Analysis. Medium formulation. In Methods in Enzymology. Recovered from sciencedirect.com.
6. Saric, M. and Lucchini, R. (2007). Manganese. Uses. In Handbook on the Toxicology of Metals (Third Edition). Recovered from sciencedirect.com.
7. Vallero, D. (2014). Neurological Effects of Air Pollutants. Manganese. In Fundamentals of Air Pollution (Fifth Edition). Recovered from sciencedirect.com.
8. Chée, R. (1986). In vitro culture of Vitis: the effects of light spectrum manganese sulfate and potassium iodide on morphogenesis. Plant Cell, Tiss and Organ Cult 7: 121-134 (1986). Recovered from link.springer.com.