Reaction of Manganese and hydrogen peroxide

[Moogie]

Hi

In a recent lab I reacted Mn2+ ions with NaOH. The Mn 2+ ions exist in this equilibria

[Mn(H20)₆]²⁺ + H₂0 <=>
[Mn(H20)₅OH]⁺ + H₃0⁺

Addition of NaOH ions shift this equilibria to the left (by removing protons) until Mn(OH)2 is precipitated

Hydrogen peroxide is then added and some gas is released and a brown precipiate formed. I presume the peroxide is oxidising the Mn2+ ions but I don't know what the precipitate is or how to balance the reaction. Some possibilities are Mn0₂ and Mn₂O₃ which are manganese oxides in a higer oxidation state.

thanks

 

[Borek]

Mn₂O₃ is not that easy to make.

 

[Moogie]

I went for MnO2. I also used the redox reaction for hydrogen peroxide under basic conditions

 

[Borek]

Sounds reasonable.

 

[DeeNos]

for sharing your lab results. It seems that the addition of hydrogen peroxide has caused the oxidation of the Mn2+ ions to a higher oxidation state, resulting in the formation of a brown precipitate. The exact composition of the precipitate will depend on the reaction conditions and the concentration of the reactants. It is likely that the precipitate is a mixture of manganese oxides, such as MnO2 or Mn2O3, as you mentioned. Balancing the reaction will require further experimentation and analysis. Overall, your results suggest that hydrogen peroxide can act as an oxidizing agent for manganese ions, which is an important reaction in many industrial and biological processes.