Write IUPAC name for each of the following complexes :
(i) `[Ni(NH_3)_6]Cl_2`
(ii) `K_3[Fe(CN)_6]`
(iii) `[Co(en)_3]^(3+)`

Explanation

(i) `[Ni(NH_3)_6]Cl_2` -Hexaamminenickel (II) chloride
(ii) `K_3(Fe(CN)_6]` -Potassium hexacyanoferrate (III)
(iii) `[Co(en)_3]^(3+)` -Trisethylenediaminecobalt(III) ion