Question

please give IUPAC name of [Co(H2O)4(NH3)2]Cl3 with explanation.

Answer 1

The following methods can be used to assist in describing the composition of a compound:

(i) The oxidation number of the central atom in a coordination entity may be indicated by a Roman numeral appended in parentheses to the central atom name but only if the oxidation state can be defined without ambiguity. When necessary a negative sign is placed before the number. Arabic zero indicates the oxidation number zero.

(ii) Alternatively, the charge on a coordination entity may be indicated. The net charge is written in arabic numbers, with the number preceding the charge sign, and enclosed in parentheses. It follows the name of the central atom without the intervention of a space.

(iii) The proportions of ionic entities in a coordination compound may be given by using multiplicative prefixes.
Therefore, correct systematic names for the compound [Co(NH3)5H2O]Cl3[Co(NHX3)X5HX2O]ClX3 are:

1-pentaammineaquacobalt(III) chloride
2-pentaammineaquacobalt(3+) chloride
3-pentaammineaquacobalt(III) trichloride
4-pentaammineaquacobalt(3+) trichloride