Iron (III) Oxide consists of the elements Iron and Oxygen. Iron is a metal present in group 8 of the periodic table. Its atomic number is 26 and is represented by the symbol Fe. It is known as the most used and cheapest metal as it is the chief constituent of the earth’s core. Oxygen is highly reactive non=metal. It is present in the chalcogen group in the periodic table. Its atomic number is 8 and is represented by the symbol O. Oxygen is an oxidizing agent and forms oxides with many elements.
What is Iron (III) Oxide?
Iron (III) Oxide is an inorganic compound and one of the most common oxides. Its chemical formula is Fe2O3. In Latin, Iron is called a Ferrum.
The valency of the Iron is 2 and 3. When it combines with valency 2, It is called Ferrous and when it combines with valency 3, It is called Ferric. Iron (III) Oxide occurs naturally in rocks of all ages. IUPAC name of Iron (III) Oxide is Ferric Oxide. It is also called Hematite or Red Iron Oxide as it appears in Red-Brown color. It is an odorless and neutral compound as the pH value is 7.
Structure of Iron (III) Oxide
Iron (III) oxide consists of 3 oxygen atoms and two Iron atoms. Here Iron is metal and Oxygen is non-metal. So bonds formed between Iron and Oxygen are called Ionic bonds. The bond formation in Iron (III) oxide depends on the difference in electronegativity between Iron and Oxygen atoms.
Iron (III) Oxide Structure
Preparation of Iron (III) Oxide
Iron (III) Oxide is obtained from the oxidation of Iron. In laboratories, it is prepared by electrolyzing the sodium bicarbonate solution along with inert electrolyte & Iron anode.
4Fe + 3O2 + 2H2O ⇢ 4FeO(OH)
The resultant hydrated Iron (III) Oxide FeO(OH) is dehydrated at 200°C to produce Ferric Oxide.
2FeO(OH) ⇢ Fe2O3 + H2O
Physical Properties of Iron (III) Oxide
- Chemical Formula- Fe2O3
- Molecular Weight– 159.69 gram/mol
- Melting Point– 1475°C to 1565°C
- When boiled Iron (III) Oxide gets decomposed.
- Density– 5.242 g/cm3
- Appears in reddish-brown color and it is in solid form at room temperature.
- Ferric oxide is odorless.
- It does not conduct electricity.
Chemical Properties of Iron (III) Oxide
- Iron (III) Oxide is not soluble in water but soluble in strong acid.
- When it is dissolved in water it forms a weak base called Ferric Hydroxide.
- The oxidation state of Iron in oxide is +3.
- Carbothermal Reduction: Reducing the Iron (III) Oxide with a reducing agent like carbon gives the metal present in oxide i.e., Iron. It is applicable to all metal oxides.
Fe2O3 + 3CO ⇢ 2Fe + 3CO2
- Exothermic thermite reaction: The Exothermic thermite reaction between Iron (III) Oxide and Aluminium gives Iron and Aluminium oxide.
2Al + Fe2O3 ⇢ 2Fe + Al2O3
Uses of Iron (III) Oxide
- Ferric oxide is used as feedstock in the production of Iron.
- Used to apply the final polish to metal jewelry and as a pigment.
- Acts as an important ingredient in calamine lotion.Used as a pigment.
- Used in magnetic disks and tapes.
- It is used in cosmetics.
- Also used in Dental composites.
Sample Questions
Question 1: Is Iron (III) Oxide acidic or basic?
Answer:
Iron (III) Oxide is an atmospheric oxide of Iron. All the oxides of Iron, Aluminum and Tin exhibits both acidic and basic nature. So Iron (III) Oxide exhibits both qualities of acidic and basic.
Question 2: Explain carbothermal reduction of Ferric oxide?
Answer:
Reduction of Ferric oxide with reducing agents such as carbon at temperature range of several hundred degree Celsius form Iron. The chemical reaction is given by-
Fe2O3 + 3CO ⇢ 2Fe + 3CO2
Question 3: Find the molecular weight of Iron (III) Oxide?
Answer:
Atomic weight of 1 Iron atom=55.845
Atomic weight of 1 oxygen atom=15.999
Molecular weight of Iron (III) Oxide (Fe2O3)=(2×55.845)+(3×15.999)
=159.68
Molecular weight of Iron (III) Oxide is 159.68
Question 4: What is the result of an Exothermic thermite reaction with Aluminum?
Answer:
The result of Exothermic thermite reaction with Aluminum gives Iron and Aluminum Oxide. The chemical reaction is given as-
2Al + Fe2O3 ⇢ 2Fe + Al2O3
Question 5: State the general uses of Iron (III) Oxide?
Answer:
Iron (III) Oxide is used in polishing the glass, metals, diamonds. It is also used in paints, inks, rubber products and also in glass as a UV blocking agent. In medical field, Ferric oxide is used in dental composites.