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

Oct 15, 2016

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

#### Explanation:

An example is the oxidation of $\text{Co"^"2+}$ to $\text{Co"^"3+}$ by hydrogen peroxide.

If you add an excess of ${\text{NH}}_{3}$ to a solution of $\text{Co"^"2+}$ ions, you get the hexaamminecobalt(II) ion, $\text{Co"("NH"_3)_6^"2+}$.

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

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"^"-"