Iron III oxide is a compound formed by the chemical combination of iron and oxygen. It is commonly known as rust and has a reddish-brown color.
| IUPAC Name | Iron(III) oxide |
| Molecular Formula | Fe2O3 |
| CAS Number | 1309-37-1 |
| Synonyms | Ferric oxide, Hematite, Iron sesquioxide, Rust |
| InChI | InChI=1S/2Fe.3O |
Iron III Oxide Properties
Iron III Oxide Formula
The formula of Iron III oxide is Fe2O3. It signifies that each molecule of Fe2O3 contains two atoms of iron and three atoms of oxygen. This chemical formula represents the ratio of elements in the compound.
Iron III Oxide Molar Mass
The molar mass of Fe2O3 can be calculated by adding the atomic masses of its constituent elements. Iron has an atomic mass of 55.845 g/mol, and oxygen has an atomic mass of 16.00 g/mol. Thus, the molar mass of Fe2O3 is approximately 159.69 g/mol.
Iron III Oxide Boiling Point
Fe2O3 does not have a distinct boiling point because it undergoes decomposition upon heating. However, it starts to decompose around 1,565°C (2,849°F). At high temperatures, Fe2O3 decomposes into iron and oxygen gases.
Iron III Oxide Melting Point
Fe2O3 has a relatively high melting point. It melts at approximately 1,565°C (2,849°F). This temperature is higher than the melting point of iron metal, which is around 1,538°C (2,800°F). Heating Fe2O3 causes it to melt and transform into a liquid state.
Iron III Oxide Density g/mL
The density of Fe2O3 is about 5.24 g/mL. It is a solid compound with a relatively high density, indicating that it is heavier compared to an equal volume of water. The density of a substance is a measure of its mass per unit volume.
Iron III Oxide Molecular Weight
The molecular weight of Fe2O3 is calculated by summing the atomic weights of its constituent atoms. Since Fe2O3 contains two iron atoms and three oxygen atoms, the molecular weight can be calculated as follows (2 x 55.845 g/mol) + (3 x 16.00 g/mol) = 159.69 g/mol.
Iron III Oxide Structure
Fe2O3 has a crystal lattice structure. It forms a network of iron and oxygen atoms held together by strong ionic bonds. The arrangement of atoms in the lattice gives rise to its physical properties, such as hardness and brittleness.
Iron III Oxide Solubility
Fe2O3 is insoluble in water and most organic solvents. It does not readily dissolve or dissociate into ions when in contact with these substances. However, it can react with strong acids to form iron salts and water. The solubility of Fe2O3 is limited in various solvents.
| Appearance | Reddish-brown solid |
| Specific Gravity | 5.24 g/mL |
| Color | Reddish-brown |
| Odor | Odorless |
| Molar Mass | 159.69 g/mol |
| Density | 5.24 g/mL |
| Melting Point | 1,565°C (2,849°F) |
| Boiling Point | Decomposes |
| Flash Point | Not applicable |
| Water Solubility | Insoluble |
| Solubility | Insoluble in water and most other solvents |
| Vapour Pressure | Not applicable |
| Vapour Density | Not applicable |
| pKa | Not applicable |
| pH | Neutral |
Iron III Oxide Safety and Hazards
Fe2O3 does not pose significant health hazards under normal conditions. However, it is essential to handle it with care. Inhalation of fine Fe2O3 particles should be avoided as it may irritate the respiratory system. Direct contact with the eyes or skin may cause mild irritation. When working with Fe2O3, it is advisable to wear appropriate personal protective equipment, including gloves and safety goggles, to prevent any potential skin or eye irritation. In case of accidental ingestion or prolonged exposure, seeking medical attention is recommended. It is also important to follow proper storage and disposal guidelines to prevent environmental contamination.
| Hazard Symbols | None |
| Safety Description | – Avoid inhalation of dust particles \n- Wear appropriate protective equipment \n- Handle with care |
| UN IDs | Not applicable |
| HS Code | 2821.10.00 |
| Hazard Class | Not classified |
| Packing Group | Not applicable |
| Toxicity | Low toxicity to humans when handled properly |
Iron III Oxide Synthesis Methods
There are several methods to synthesize Fe2O3. One common approach is the oxidation of iron in the presence of oxygen. Iron can react with atmospheric oxygen, especially in the presence of moisture, to form a layer of Fe2O3, commonly known as rust. This process occurs naturally over time on exposed iron surfaces.
Another method involves the thermal decomposition of iron(III) hydroxide or iron(III) nitrate. Heating Iron(III) hydroxide releases water and oxygen, forming Fe2O3. Similarly, heating iron(III) nitrate also leads to the decomposition of the compound, forming Fe2O3 along with nitrogen dioxide and oxygen as byproducts.
Precipitation reactions can be used to synthesize Fe2O3. This method involves mixing iron salts, such as iron(II) sulfate or iron(III) chloride, with an alkaline solution, such as sodium hydroxide or ammonium hydroxide. Further heating or oxidation of the precipitate, Iron III hydroxide, yields Fe2O3.
Various techniques, such as sol-gel methods, hydrothermal synthesis, and co-precipitation techniques, enable the synthesis of Fe2O3 nanoparticles. These methods often involve the controlled precipitation or formation of nanoparticles from iron precursors in the presence of suitable stabilizing agents or surfactants.
It is important to note that the specific synthesis method chosen depends on the desired properties and application of the Fe2O3 product. Each method has its advantages and considerations in terms of cost, scalability, purity, and particle size control.
Iron III Oxide Uses
Fe2O3 finds numerous applications due to its distinct properties. Some of its common uses include:
- Pigment: Paints, coatings, and dyes widely use Fe2O3 as a pigment, imparting a desirable reddish-brown hue to various materials.
- Polishing Agent: Metal finishing processes utilize Fe2O3 as a polishing agent to smoothen and enhance the appearance of metal surfaces.
- Catalyst: Fe2O3 acts as a catalyst in chemical reactions, such as the production of ammonia or the water-gas shift reaction.
- Magnetic Material: Manufacturers employ Fe2O3 in the production of magnetic recording media, such as tapes and disks, due to its magnetic properties.
- Chemical Reagent: Various laboratory experiments utilize Fe2O3 as a chemical reagent, particularly in redox reactions and the synthesis of other compounds.
- Photocatalysis: Photocatalytic applications, such as wastewater treatment and solar energy conversion, show potential for Fe2O3 nanoparticles.
- Pigment for Ceramics: In the ceramics industry, Fe2O3 functions as a pigment for glazes, adding color and visual appeal to ceramic products.
- Concrete Additive: Fe2O3 is an additive in concrete, improving its strength, durability, and aesthetic appearance of concrete structures.
- Electrode Material: Certain types of batteries, like lithium-ion batteries, use Fe2O3 as an electrode material.
- Pharmaceutical Applications: Researchers explore Fe2O3 nanoparticles in drug delivery systems and imaging applications within the field of medicine.
These are just a few examples of the diverse applications of Fe2O3, demonstrating its versatility in various industries.
Questions:
Q: What is the formula for iron (III) oxide?
A: The formula for iron (III) oxide is Fe2O3.
Q: How many moles of iron are in 4 moles of iron (III) oxide?
A: In 4 moles of Fe2O3, there are 8 moles of iron.
Q: What mass of O2 is required to oxidize the iron to iron (III) oxide?
A: To oxidize iron to Fe2O3, 3 moles of O2 are required for every 4 moles of iron.
Q: How many atoms are in iron (III) oxide?
A: In one molecule of Fe2O3 there are 5 atoms.
Q: What is the mass of iron in 35.0 g of rust (ferric oxide or iron (III) oxide)?
A: The mass of iron in 35.0 g of rust (Fe2O3) is approximately 23.3 g.
Q: Why does rust form as iron (III) oxide, and not iron (II) oxide?
A: Rust forms as Fe2O3 because iron (II) oxide readily reacts with oxygen in the air, further oxidizing to form Fe2O3.
Q: Which pH value would you expect iron (III) oxide to have?
A: Fe2O3 is not soluble in water and is not acidic or basic, so it does not have a significant effect on pH.
Q: What is the density of iron (III) oxide?
A: The density of Fe2O3 is approximately 5.24 g/mL.
Q: How many atoms are in a molecule of iron oxide (Fe2O3)?
A: There are 5 atoms in a molecule of iron oxide (Fe2O3).
Q: What is Fe2O3?
A: Fe2O3 is the chemical formula for iron (III) oxide, also known as rust.
Q: How many molecules are in 79g of Fe2O3?
A: There are approximately 4.08 x 10^23 molecules in 79 g of Fe2O3.
Q: How to balance Fe2O3 + C = Fe + CO2?
A: The balanced equation is 2Fe2O3 + 3C = 4Fe + 3CO2.
Q: Which element is oxidized in this reaction? Fe2O3 + 3CO → 2Fe + 3CO2.
A: Carbon (C) is oxidized in this reaction.
Q: Is Fe2O3 ionic or covalent?
A: Fe2O3 is an ionic compound.
Q: Which substance is the oxidizing agent in this reaction? Fe2O3 + 3CO → 2Fe + 3CO2.
A: Fe2O3 is the oxidizing agent in this reaction.
Q: What is the name for Fe2O3?
A: The name for Fe2O3 is ferric oxide or rust