Why is #KMnO_4# an oxidizing agent?

1 Answer
Aug 11, 2016

Answer:

Because manganese metal is in its highest oxidation state (#Mn(VII+)#, and it is likely to be reduced in any reaction.

Explanation:

And if it is likely to be reduced, it is an electron sink, and therefore an #"oxidizing agent"#. Typically, permanganate is reduced to colourless #Mn^(2+)#:

#MnO_4^(-) + 8H^(+) + 5e^(-)rarr Mn^(2+) + 4H_2O#

Mass and charge are balanced here, so at least the reaction is viable. The macroscopic change is usually from deeply purple permanganate to almost colourless #Mn^(2+)# ion, so this reaction is convenient in that it is self-indicating.