Give systematic names for the following formulas:

(a)$\mathbf{\left[}\mathbf{C}\mathbf{o}{\left(N{H}_3\right)}_{\mathbf{4}}{\left(N{O}_2\right)}_{\mathbf{2}}\mathbf{\right]}\mathit{C}\mathit{l}$

(b)$\mathbf{\left[}\mathbf{C}\mathbf{r}{\left(N{H}_3\right)}_{\mathbf{6}}\mathbf{\right]}\mathbf{\left[}\mathbf{C}\mathbf{r}{\left(CN\right)}_{\mathbf{6}}\mathbf{\right]}$

(c)${\mathit{K}}_{\mathbf{2}}\mathbf{\left[}\mathbf{C}\mathbf{u}\mathbf{C}{\mathbf{l}}_{\mathbf{4}}\mathbf{\right]}$

A coordination complex consists of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents.

In order to solve problems like this, there are some rules for naming coordination compounds:

- cation is named before anion

- In the complex ion, we name ligands before metal ion, in alphabetical order

- A numerical prefix is the number of ligands of particular type

- The oxidation state of metal ion is written by roman numerals in parentheses if the metal ion has more than one oxidation state

- If the complex ion is an anion, we add -ate instead of the ending of metal name

- Neutral ligands most often have molecule name, but anionic ligands lose the -ide and add -o after the root name

So, these are solution of given compounds

a)$\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_4{\left({\mathrm{NO}}_2\right)}_2\right]Cl$- tetra amine di nitro cobalt(III)chloride

b)$\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_6\right]\left[\mathrm{Cr}{\left(\mathrm{CN}\right)}_6\right]$- hexa amine chromium (III)hexa cyano chromate(III)

c)$K_2\left[{\mathrm{CuCl}}_4\right]$- potassium tetra chloro cuprate(III)