Question

Write the formulas for the following coordination compounds:
Tetraamminediaquacobalt (III) chloride.

Answer 1

The coordination compound consists of a metallic central atom or ion, which is called the coordination centre that is surrounded by molecules or ions, which are known as ligands.

Complete step by step answer:
We need to determine the formula for the coordination compound named as Tetraamminediaquacobalt (III) chloride. From the name of this coordination compound certain points can be concluded that are the amine and aqua that is water, are the ligands as according to the rules of naming the coordination compounds, the ligands are named before the metal ion. If more than one ligands are present, then their names are written in alphabetical order. Thus, the name of the ligand amine is written before naming the ligand aqua. Always remember, that the words like ${}^\backprime tetra'$ and ${}^\backprime di'$ are only used to represent how many numbers of that particular ligand are being attached to the central metal ion. These words have nothing to do with the naming of ligands.
Therefore, from the given name of the compound, it is clear that four molecules of ammine and two molecules of water (aqua) are attached with the metal ion. The central metal ion in this compound is cobalt with the oxidation state of three written in the parenthesis in the roman numerals. Then, at least, the chloride ions are attached to this coordination complex as an anion.
Hence, the formula for Tetraamminediaquacobalt (III) chloride can be written as:
$\left[ {Co{{\left( {{H_2}O} \right)}_2}{{\left( {N{H_3}} \right)}_4}} \right]C{l_3}$

Additional information:
when naming a complex ion, the ligands are named before the metal ion. Write the names of the ligands in the following order: neutral, negative and at last positive.

Note: In the naming of coordination compounds, the cations are named always before the anions. In the naming of ligands also, the order is neutral, negative and then positive ligands in the alphabetical order.