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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: RGraham9 on September 19, 2016, 09:54:05 AM

Title: Oxidation of Alcohol with Acidified Potassium Permanganate KMNO4/H+
Post by: RGraham9 on September 19, 2016, 09:54:05 AM

Hey guys , just curious , what actually happens when we add KMnO4/H+ to primary and secondary alcohols ? Will any precipitate form ? Because having seen some of the different experiments on YouTube , some experiments seem to have produced a brown precipitate upon the addition of the KMnO4/H+ to the primary / secondary alcohol while some don't seem to produce the brown precipitate at all. Why is this so ?

Extra-Detail : I have been told that the brown precipitate is actually MnO2. But why is it present in some of the experiments and not present in others ?

Sorry for the trouble guys. Do let me know if any part of my question is unclear and needs further elaboration. Thank you !

Title: Re: Oxidation of Alcohol with Acidified Potassium Permanganate KMNO4/H+
Post by: Borek on September 19, 2016, 10:52:42 AM

Quote from: RGraham9 on September 19, 2016, 09:54:05 AM

But why is it present in some of the experiments and not present in others ?

pH

Title: Re: Oxidation of Alcohol with Acidified Potassium Permanganate KMNO4/H+
Post by: RGraham9 on September 19, 2016, 11:10:20 AM

Ah so the difference between an experiment that has a precipitate of MnO2 and an experiment that does not have a precipitate of MnO2 is a result of the acidity of the acid used to acidify the KMnO4 correct ?
Thank you so much for the clarification !