Question: what happens when hydrogen peroxide reacts with acidified kmno4?
Answer: Manganate(VII) ions, MnO4-, oxidise hydrogen peroxide, H2O2, to oxygen gas. The reaction is done with potassium manganate(VII) solution and hydrogen peroxide solution acidified with dilute sulphuric acid. During the reaction, the manganate(VII) ions are reduced to manganese(II) ions.