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"^"-"#