Can a metal in a complex ion undergo a redox reaction?

1 Answer
Oct 15, 2016

Yes, the metal in a complex ion can undergo reduction-oxidation reaction.

Explanation:

An example is the oxidation of "Co"^"2+" to "Co"^"3+" by hydrogen peroxide.

If you add an excess of "NH"_3 to a solution of "Co"^"2+" ions, you get the hexaamminecobalt(II) ion, "Co"("NH"_3)_6^"2+".

This is oxidized rapidly by hydrogen peroxide to the hexaamminecobalt(III) ion, "Co"("NH"_3)_6^"3+".

The equation for the reaction is

underbrace("2Co"("NH"_3)_6^"2+")_color(red)("yellow-brown") + "H"_2"O"_2 → underbrace("2Co"("NH"_3)_6^"3+")_color(red)("deep orange-brown") + "2HO"^"-"