BOD titration. We add the manganese sulfate, the sodium iodide azide and concentrated sulfuric acid, but the solution goes colorless. Why?

We doing this as a high school project of BOD on pond water and are following a video method (https://www.youtube.com/watch?v=QZXlIbeGWA0) we found on the internet and we get a pale brown ppt...

28 September 2023 8,478 1 View