Answer:
The complex formed between Co3+ and NH3 is [Co(NH3)6]^3+ and is called Hexaminecobalt(III).
Explanation:
The first step in the syntheses of these complexes requires oxidation to convert the metal from the +2 to the +3 oxidation state
2Co2+ → 2Co3+ + 2e-
2Co3+ + 12NH3 → 2[Co(NH3)6] ^3+
The netto reaction will be:
2Co2+ + H2O2(aq)+ 12NH3 → 2 [Co(NH3)6] ^3+ + 2OH-
Hydrogen peroxide as an oxidizing agent generates only OH– as reduced product, and the presence of ammonia guarantees that the Co3+ will be stabilized immediately by formation of amine component.
The complex formed between Co3+ and NH3 is [Co(NH3)6]^3+ and is called Hexaminecobalt(III).
