The equation Cr2O3 + 2HCl -> 2CrCl3 + 3H2O

Detailed information about the chemical equation:
The chemical equation above describes the chemical reaction between iron (III) oxide (Cr₂O₃) and hydrochloric acid (HCl), resulting in the formation of iron (III) chloride (CrCl₃) and water (H₂O).

Reaction conditions:
For the reaction to occur, the necessary condition is that iron (III) oxide and hydrochloric acid must come into direct contact with each other in a sufficiently high temperature environment.

The Reaction process:

• Cr₂O₃ is an oxide of the metal chromium. When it encounters HCl, it transforms into CrCl₃ and generates H₂O.
• Thus, each molecule of Cr₂O₃ reacts with 2 molecules of HCl to produce 2 molecules of CrCl₃ and 3 molecules of H₂O.
• If the number of molecules of any substance is insufficient, the reaction will not fully occur, leading to the presence of excess substance, which does not dissolve completely.

Phenomenon that occurs:
When the green solid of Cr₂O₃ is added to the hydrochloric acid solution, the reaction occurs with the formation of the green solution of CrCl₃ and water vapor.