What is Cr2O3? Important knowledge about Cr2O3.

1. Definition of Cr₂O₃:

1.1 Names:
1.1.1 Common name: Cr₂O₃ is known as Chromium Iron.
1.1.2 English name: Chromium Iron is called Chromium(III) oxide or chromic oxide.
1.2. Atomic structure: Cr₂O₃ consists of 2 Chromium atoms and 3 Oxygen atoms.
1.3. Molar mass: The molar mass of Cr₂O₃ is 151.9904 g/mol.
1.3.1 Molecular structure: The molecule of Cr₂O₃ consists of 2 Chromium atoms linked to 3 Oxygen atoms.
1.4 Ionic structure: Cr₂O₃ does not form ions under normal conditions.

2. Properties of Cr₂O₃:
   2.1 Physical properties of Cr₂O₃:
   State: Solid at room temperature.
   Color: Green to black.
   Smell: Odorless.
   pH: Not applicable as Cr₂O₃ is a solid.
   2.2 Chemical properties of Cr₂O₃: It is quite stable at high temperatures, insoluble in water and common acids.

3. Common chemical reactions of Cr₂O₃:
   3.1 Reaction with metals: Cr₂O₃ can react with metals like Al, Fe, Mg…
   3.2 Reaction with acid: Cr₂O₃ reacts with strong acids like H₂SO₄, HCl.
   3.3 Reaction with non-metals: Cr₂O₃ does not react with non-metals under normal conditions.
   3.4 Reaction with salts: Cr₂O₃ does not react directly with salts.

4. Synthesis of Cr₂O₃:

4.1 Laboratory synthesis of Cr₂O₃: Cr₂O₃ is typically synthesized from the reaction between CrCl₃ and NaOH, then heated.
4.2 Industrial synthesis of Cr₂O₃: Industrially, Cr₂O₃ is produced by reducing Cr₂O₃ with coal in a sealed container.