Question

Ammonia gas does not evolve from the complex $Fe{Cl}_3\cdot 4N{H}_3$ but it gives white precipitate with aqueous solution of $AgN{O}_3$. Coordination number of central metal ion in above complex is six. Give IUPAC name of the complex:

• A. Ammonium trichloro triammine ferrum (III)
• B. Tetraammine ferrum (III) chloride
• C. Dichloro tetraammine ferrate (II) chloride
• D. Dichloro tetraammine ferrum (III) chloride

Answer 1

The correct option is D Dichloro tetraammine ferrum (III) chloride

In complex $Fe{Cl}_3\cdot 4N{H}_3$, coordination number of central metal ion is six. The complex compound does not evolve the ammonia gas but it gives white precipitate with aqueous solution of $AgN{O}_3$ which confirms the presence of one ${Cl}^{-}$ ion in ionisation sphere, hence, the coordination compound is $\left[Fe{Cl}_2{\left(N{H}_3\right)}_4\right]Cl$. The IUPAC name of complex compound is dichloro tetraammine ferrum (III) chloride.