What Is Fe2O3? Chemical Properties, Formula, and Everyday Applications
Inorganic Chemistry is a fascinating part of Chemistry. The metal oxides are included in the chapter related to metallurgy where students will learn how these oxides are prepared and used in various industrial processes. One of the oxides you will study in this section is Iron III oxide. The chemical properties of this oxide need to be properly studied as the questions are quite conceptual.
To make it easier for students, Vedantu has developed a concept page focusing on the oxide and its physical and chemical properties. This page has been developed by the top Chemistry teachers. It addresses the basic problems a student faces while studying this particular oxide. It will also help to develop a clear concept so that students can easily clarify doubts arising in their minds on their own. You will learn what is the chemical formula of ferric oxide and its various properties to get a hold of this concept. Keep on reading and use this concept page as your revision note to ace the exams.
Iron(III) Oxide: What are its Formula and Chemical Properties?
Iron III oxide is one of the most common oxides you have studied in the previous classes. You will find more elaborate information related to this oxide when you advance to a higher class. This time, a section of the chapter has been dedicated to this oxide so that you can learn how it behaves in different physical and chemical conditions.
The chemical formula of Iron III oxide is Fe2O3. It is obtained from a mineral ore called hematite. It is mined and then processed to obtain iron oxide for extracting the metal. Iron is also called Ferrum in Latin. The valency of this metal is 2 and 3. When it combines with valency 3, it is called Ferric. When it combines with other elements showing valency 2, it is called Ferrous. In this segment, we will study about this Iron Oxide and its chemical properties. The IUPAC name of Fe2O3 is Ferric Oxide. This oxide occurs in nature in a neutral state as it is properly balanced in terms of valence electrons.
Production of Iron(III) Oxide:
On oxidation of iron, Iron(III) oxide can be obtained. In laboratories, by electrolyzing sodium bicarbonate solution with an inert electrolyte and iron anode, Iron(III) oxide is produced.
4Fe + 3O2 + 2H2O → 4FeO(OH)
The hydrated iron(III) oxide when dehydrated at 200°C produces Iron(III) oxide alongside the water.
2FeO(OH) → Fe2O3 + H2O
Let Us Check the Physical Properties of This Oxide
The chemical name of Fe2O3 is Iron(III) oxide.
Molecular Weight/ Molar Mass of Iron(III) oxide is 159.69 g/mol.
The density of Iron(III) oxide is 5.242 g/cm³.
The Iron(III) oxide when boiled gets decomposed.
The Melting Point of Iron(III) oxide is 1475°C – 1565°C.
In this section, you will find out how Iron III oxide is formed by chemically reacting with oxygen and forming the electrovalent bonds. The proper description of the chemical structure along with an illustrated image will help you grab hold of the concept properly. In fact, you will also find how the systematic name for Fe2O3 is given by the Chemistry experts. Understand the importance of the name and how it is assigned to this oxide for future references. By learning the method, you can also understand and discover how other oxides are named.
Chemical Properties of Iron III Oxide
As you all know that this is an oxide included in the Chemistry chapter related to metals, you will have to study its chemical properties elaborately. On this concept page, you will find out how the experts have perfectly segmented the properties along with good examples. This elaboration has been done using simple language so that students of all merit levels can understand it properly.
Carbothermal reduction – Reduction of metal oxides with a reducing agent i.e., carbon at several hundred degrees Celsius.
Fe2O3 + 3CO → 2Fe + 3CO2
Exothermic thermite reaction with aluminum –
2Al + Fe2O3 → 2Fe + Al2O3
Let Us Take a Quick Look into the Chemical Properties of Iron III Oxide Fe2O3 .
Iron III oxide is basic in nature. It forms a weak base when dissolved in water. The name of that base is Ferric Hydroxide (Fe(OH)3).
Its alkaline properties can be observed when it reacts with an acid to form the respective inorganic salt and water at the end of an acid-base reaction.
The oxidation state of the metal in this oxide is +3.
It is not soluble in water but strongly soluble in strong acid.
You will find the proper elaboration of these properties along with the iron 3 oxide balanced equation for each one of the points.
Uses of Iron(III) Oxide (Fe2O3)
After learning the Fe2O3 chemical name and chemical properties, you will proceed to the section where you will find its uses. It is used to manufacture die inks for stamping. It is the prime constituent used in various industries manufacturing pain, plastic, pharmaceutical products, ink and cosmetics. It is also used as a natural pigment.
Iron(III) oxide is used in the production of iron as a feedstock.
It can be used as a pigment.
It can be used in cosmetics.
It can be used in dental composites.
It can be an important ingredient in calamine lotion.
It can be used to apply the final polish on metallic jewelry.
It can be used in magnetic disks and magnetic tapes.
FAQs on Iron(III) Oxide (Fe2O3): Properties, Structure & Uses
1. What is Iron(III) oxide and what are its common names?
Iron(III) oxide is an inorganic compound with the chemical formula Fe₂O₃. It is one of the main oxides of iron. In this compound, iron has an oxidation state of +3. It is commonly known as ferric oxide or, in its naturally occurring mineral form, as hematite. It is the primary component of rust.
2. What are the key physical properties of Iron(III) oxide (Fe₂O₃)?
Iron(III) oxide has several distinct physical properties that are important for its identification and application. These include:
Appearance: It is a reddish-brown solid at room temperature.
Odour: It is an odourless compound.
Solubility: It is practically insoluble in water but dissolves in strong acids.
Melting Point: It has a high melting point of 1566 °C (2851 °F).
Density: The density is approximately 5.24 g/cm³.
Conductivity: It is an electrical insulator, meaning it does not conduct electricity.
3. What are the major uses of Iron(III) oxide in industries and daily life?
Iron(III) oxide has a wide range of applications due to its colour, stability, and magnetic properties. Some important uses include:
Pigments: It is widely used as an inexpensive and durable pigment known as 'Pigment Red 101' in paints, coatings, and coloured concretes.
Polishing: A fine powder of ferric oxide, known as 'jeweller's rouge', is used for polishing metallic lenses, glass, and precious metals.
Magnetic Storage: It is the magnetic particle used in magnetic storage devices like audio cassettes and data tapes.
Industrial Processes: It is the raw material for the production of iron and steel in a blast furnace. It is also used as a catalyst in various chemical reactions.
4. How is Iron(III) oxide (Fe₂O₃) prepared?
Iron(III) oxide is most commonly formed by the oxidation of iron. In a laboratory setting, it can be prepared by the thermal decomposition of other iron compounds, such as iron(III) hydroxide or iron(II) sulfate. For example, heating iron(III) hydroxide dehydrates it to form iron(III) oxide and water, as shown in the equation:
2Fe(OH)₃(s) + Heat → Fe₂O₃(s) + 3H₂O(g)
Industrially, it is obtained from its principal ore, hematite, which is mined directly.
5. What is the difference between Iron(II) oxide (FeO) and Iron(III) oxide (Fe₂O₃)?
The primary difference between Iron(II) oxide and Iron(III) oxide lies in the oxidation state of the iron atom. In Iron(II) oxide (ferrous oxide), iron has an oxidation state of +2, with the formula FeO. In Iron(III) oxide (ferric oxide), iron has an oxidation state of +3, with the formula Fe₂O₃. This difference also leads to other contrasting properties, such as colour; FeO is a black powder, whereas Fe₂O₃ is reddish-brown.
6. Why is Iron(III) oxide considered amphoteric?
An amphoteric substance is one that can react as both an acid and a base. Iron(III) oxide demonstrates this dual nature. It acts as a basic oxide when it reacts with strong acids like hydrochloric acid to form an iron(III) salt and water (Fe₂O₃ + 6HCl → 2FeCl₃ + 3H₂O). However, it can also act as an acidic oxide by reacting with strong bases at high temperatures to form compounds called ferrates (e.g., NaFeO₂). This ability to react with both acids and bases is why Fe₂O₃ is classified as an amphoteric oxide.
7. How does the thermite reaction utilize Iron(III) oxide?
The thermite reaction is a highly exothermic redox reaction that uses Iron(III) oxide and a more reactive metal, typically aluminium. Aluminium acts as a reducing agent, displacing iron from its oxide because it is more reactive. The balanced chemical equation is:
2Al(s) + Fe₂O₃(s) → Al₂O₃(s) + 2Fe(l) + Heat
This reaction releases an immense amount of energy as heat, which is sufficient to melt the iron produced. This molten iron is then used for on-site applications like welding railway tracks or repairing large steel parts.
8. Is rust chemically the same as pure Iron(III) oxide?
No, rust is not chemically the same as pure Iron(III) oxide. While Fe₂O₃ is the main component, rust is specifically hydrated iron(III) oxide, with a general chemical formula of Fe₂O₃·nH₂O. The 'n' indicates a variable number of water molecules attached to the ferric oxide structure. This attached water is crucial and gives rust its characteristic flaky, brittle texture, which is different from the properties of anhydrous (water-free) Fe₂O₃.
9. Can you describe the crystal structure of Iron(III) oxide?
The most common and stable form of Iron(III) oxide, α-Fe₂O₃ (hematite), possesses a rhombohedral crystal structure. This structure is often referred to as the corundum (α-Al₂O₃) structure. In this arrangement, the oxide ions (O²⁻) form a nearly hexagonal close-packed (HCP) lattice. The smaller iron(III) ions (Fe³⁺) occupy two-thirds of the available octahedral interstices (holes) within this lattice, creating a very stable and compact solid.
