[Archy12345]

Recently I was synthesizing elemental bromine using the procedure from the link below. Oxidation of a bromide anion via reduction of a permanganate anion in an acidic environment.
I used sodium bromide, potassium permanganate, and sulfuric acid. Because of the acidic environment the permanganate ion should reduced to Mn²⁺, but my reaction flask was left with the blackish-brown of Manganese(IV)Oxide. I have no idea why this would be occurring because to my understanding manganese goes to a plus four state in neutral solutions, and this was very obviously acidic. Any ideas?
 

http://www.youtube.com/results?search_query=bromine+synthesis&oq=bromine+sy&gs_l=youtube.3.0.0.109.2533.0.3626.14.12.2.0.0.0.99.728.12.12.0...0.0...1ac.1.Vt9QL3jarcI

[Borek]

Your link doesn't point to a procedure, merely to the search result with many videos.

Obvious thing to check is a stoichiometry - were there enough sulfuric acid?

[Archy12345]

http://www.youtube.com/watch?v=AL9ehxTaYRs
Here is the correct link. Thank you for pointing that out.

And yes, there was an excess of sulfuric acid.

[Archy12345]

I believe I found the answer.
I used tap water as the solvent in the reaction flask. I just tested the pH of my tap water and it is slightly basic. The production of MnO₄ produces enough OH^- to neutralize the the acid enough to keep the production of MnO₄ to continue.