Write the IUPAC names of the following coordination compounds:

(i) [Cr(NH₃)₃Cl₃]

(ii) K₃[Fe(CN)₆]

(iii)[CoBr₂(en)₂]⁺, (en=ethylenediamine)

(i) There are three –NH₃ groups and 3-Cl group, so the name would be Triamminetrichloro and the chromium has oxidation number of +3 as oxidation state of NH₃ and Cl is 0 and -1 respectively. So, IUPAC name is-

Triamminetrichlorochromium(III)

(ii) Potassium would be written first as it is outside the third bracket. 6 –CN groups make the name hexacyano and the oxidation state of Fe is +3, hence ferrate (oxidation state of CNand K is -1 and +1 respectively). So, IUPAC name is-

Potassium hexacyanoferrate(III)

(iii) There are two –Br groups and 2-en groups, so the name would be dibromidobis-(ethane-1,2-diammine). The cobalt has +3 oxidation state as oxidation state of Br and -en is -1 and 0 respectively and the cation is charged by +1. So, IUPAC name is-

dibromidobis-(ethane-1,2-diammine) cobalt(III)ion.