The reaction between aniline (C₆H₅NH₂) and ferric chloride (FeCl₃) is complex and depends on the reaction conditions. However, the most common reaction leads to the formation of a dark-colored precipitate of ferric anilinium chloride [(C₆H₅NH₃)₃FeCl₆]. This reaction is an example of a complex formation reaction.

Here is the balanced equation:

3 C₆H₅NH₂ + FeCl₃ → (C₆H₅NH₃)₃FeCl₆

Explanation:

* Aniline (C₆H₅NH₂) acts as a weak base, accepting a proton (H⁺) from the acidic ferric chloride.

* Ferric chloride (FeCl₃) acts as a Lewis acid, accepting electron pairs from the aniline molecules.

* The reaction results in the formation of a complex cation, (C₆H₅NH₃)₃³⁺, where three anilinium ions (C₆H₅NH₃⁺) are coordinated to the ferric ion (Fe³⁺).

* The complex cation is then associated with six chloride ions (Cl⁻) to form the overall neutral compound, (C₆H₅NH₃)₃FeCl₆.

Important Notes:

* The reaction is typically carried out in a solution of an acidic medium, such as hydrochloric acid (HCl), to enhance the protonation of aniline and promote complex formation.

* The resulting ferric anilinium chloride is a dark-colored precipitate that is often used as a dye or indicator.

* The reaction is not always quantitative, and side reactions may occur, leading to the formation of other products.

It's worth noting that the reaction can be further complicated by the presence of other reagents or conditions, leading to different products.