Fe2S3 Structure, Characteristics: 5 Facts You Should Know

 Fe2S3 structure named iron (III)sulphide is one of the 3 important sulphides synthesized so far. Its structural representation and characteristics are illustrated in this article.

Fe2S3 structure is an ionic compound which signifies that there is the transference of electrons. Iron is a transition metal and sulphur is a non-metal. To gain stability 2 iron atoms will lose their 3 electrons which in turn will be accepted by 3 sulphur atoms thereby forming a Fe2S3 structure. Fe2S3 structure is an ionic compound and forms strong electrovalent bond.

Discussing Fe2S3 structure then it is denoted by a variety of names like Iron (III)sulphide, ferric sulphide and sesquisulfide. Fe2S3 structure is an inorganic compound of solid black powder but on careful temperature exposure, it decays into a powdery substance of green colour. Fe2S3 structure like other iron compounds is not found in nature and is prepared synthetically or artificially in laboratories and industry.

Synthesis of Fe2S3 structure takes place in a cool or refrigerated environment. Cool iron (III) chloride solution is added to freeze sodium sulphide solution which leads to the production of Fe2S3 structure along with sodium chloride as a by-product. Another most used method of manufacturing is the passing of hydrogen sulphide gas through hydrous iron (III)oxide. This method is called desulfurization of H2S.

Transference of electrons in Fe2S3 structure

Elaborating on its properties and usages then much information is not available about the Fe2S3 structure. It is an artificial element so it is used as a precursor for many inorganic reactions or as a source to obtain sulphur and iron. Its decay leads to an orange-yellow coloured powder as it has a low boiling point and decomposes at room temperature. Apart from this Fe2S3 structure structures can be used in various metallurgical processes. Recently Fe2S3 structure has entered the nanotechnology industry where it is used for making nanocrystals and nanofibres as well.

Characteristics of any compound are related to its structural formation. So let’s discuss the Fe2S3 structure and properties related to it.

What is the Fe2S3 structure?

Fe2S3 structure comprises iron and sulphur. Iron has atomic number 26 with electronic configuration [Ar]3d64s2 and belongs to the family of transition metals. Sulphur on the flip side has atomic number 16 and electronic configuration [Ne]3s23p4 belongs to the chalcogen non-metal family.

As there are only 2 atoms involved so finding the central atom is not required. But out of Fe and S in the Fe2S3 structure, S is of more electronegativity which indicates that the electron cloud will be more aligned to the side of sulphur than iron.

To complete their octet stability requirement there will be donation and acceptance of electrons in the Fe2S3 structure. Iron being metal and the one with the least electronegativity will donate its 3 electrons to the more electronegative sulphur atom. In this bonding 2, iron atoms and 3 sulphur atoms are involved. This leads to the formation of Fe3+ cation and S2- anion.

Due to the difference of electronegativities in Fe and S in Fe2S3 structure sulphur will attract the whole electron cloud towards it and results in ionic or electrovalent bonding. An ionic bond is one of the strongest bonds. Hence Fe2S3 structure is an ionic or electrovalent compound.

There are various characteristics of a compound which depend on its bonding nature and the Fe2S3 structure is not different. Some of the most discussed characteristics are:

  1. Is Fe2S3 structure soluble in water?
  2. Is Fe2S3 structure ionic or covalent?
  3. Is Fe2S3 structure aqueous?
  4. Is Fe2S3 structure a precipitate?
  5. Is Fe2S3 structure a salt?

Is Fe2S3 structure soluble in water?

Fe2S3 structure is moderately or negligibly soluble in water. There are many iron-sourced sulphate compounds which are soluble in water but the Fe2S3 structure is an exception due to its low solubility property. Even it is not soluble in related acid sulphates. 

The exact reason behind this is still not known. But out of all iron sulphide compounds, it is relatively unstable and is formed artificially. Also, its Ksp value or degree of solubility when calculated is low. All of these factors are evidence of its negligible solubility behaviour in water.

Is Fe2S3 structure ionic or covalent?

The Fe2S3 structure is ionic. The basis of its lewis structure formation is ionic bonding. As already mentioned above it is formed by donation and acceptance of electrons due to the huge electronegativity difference between the atoms involved.

This results in the formation of cation and anion which due to strong electrovalent bonds come into each other proximity resulting in the inorganic ionic compound Fe2S3 structure.

Fe2S3 structure
Ionic Bonding in Fe2S3 structure

Is Fe2S3 structure aqueous?

Fe2S3 structure is one of the three iron sulphide structures as mentioned several times in this article. It is not aqueous nor does it show any positive behaviour in terms of solubility in an aqueous medium. The Fe2S3 structure is not aqueous.

It is an inorganic solid black powdery compound. At room temperature, it decays and its colour changes to a yellowish-green compound. This is also one of the reasons why its preparation and manufacturing take place in refrigerated or freezing conditions.

Is Fe2S3 structure a precipitate?

As the Fe2S3 structure is negligibly soluble in water, there are high chances that it precipitates. One of the preparation methods of the Fe2S3 structure is a precipitation reaction.

A double displacement reaction between Fe(NO3)3 and sodium sulphide leads to an aqueous solution of sodium nitrate and the precipitates of the Fe2S3 structure which settle at the bottom and can be separated after the reaction.

Precipitation reaction of Fe2S3 structure

Is Fe2S3 structure a salt?

Yes, the Fe2S3 structure is a salt. A salt is defined as a neutral species which is formed by the reaction between acid and base. The acid is usually derived from a non-metal family and the base is derived from the metal family. The same is the case with the Fe2S3 structure. 

To be more precise Fe2S3 structure is an inorganic salt or a sulphate salt of various other sulphuric acid type compounds formed by double displacement. This is evident from the preparation methods of the Fe2S3 structure.


Summarizing this article the Fe2S3 structure is an inorganic ionic compound which is artificially synthesized and is relatively unstable where it shows insolubility in water and is solid in its appearance.

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