When I try to add kMn04 at sulphuric acid +graphite powder solution? some chunks of kmn04 float in the solution but after a lot of stirring with a glass rod, it disappears. Why did this thing happen?
Dear Hridoy Saha ,
Nice Question You asked !
The Answer of your question...
Because KMnO4 acts as Oxidizer, Sulphuric Acid functionalize the Graphite surface to add functional groups in the presence of reagent like KMnO4. KMnO4 should be added slowly because it increases the temperature of the reaction and may lead to incomplete oxidation at the end, if poured instantly and not stirred properly.
Here is the reaction ,
2KMnO4 + 5H2O2 + 3H2SO4 ⟶ 2MnSO4 +K2SO4 +8H2O(steam) + 5O2
You may want to check out the following article :
1. Mechanism of Graphene Oxide Formation
Article Mechanism of Graphene Oxide Formation
2.Graphene Oxide Chemistry Management via the Use of KMnO4/K2Cr2O7 Oxidizing Agents
Article Graphene Oxide Chemistry Management via the Use of KMnO4/K2C...
I hope this helps. Good luck with your research !
Best wishes & Regards ,
Vishwajit Chavda
https://www.researchgate.net/topic/hummers_method,kindly check this link.
Concentration of Sulphuric Acid: Concentration of Sulphuric Acid is most important in Hummers method. ... Effect of KMnO4: In this method, KMnO4 acts as Oxidizer, Sulphuric Acid functionalize the Graphite surface to add functional groups in the presence of reagent like KMnO4.
https://instanano.com › carbon › gra...
Graphene Oxide (GO) Synthesis by Modified Hummer's Method
Hummers' method is a chemical process that can be used to generate graphite oxide through the addition of potassium permanganate to a solution of graphite, sodium nitrate, and sulfuric acid. ... It is also able to be revised in the creation of a one-molecule-thick version of the substance known as graphene oxide.
https://en.m.wikipedia.org › wiki
Hummers' method - Wikipedia
Dear Hridoy Saha this is a very good and interesting technical question. When you add solid potassium permanganate (KMnO4) to concentrated sulfuric acid it is not just a dissolution of the permanganate in H2SO4. What many people don't know is that a reaction takes place between the two compounds. This is the reason why it takes a while until the crystals of KMnO4 dissolve in the acid after some stirring. The reaction product is Mn2O7, which is the anhydride of permanganic acid. Mn2O7 is an oily liquid which is soluble in concentrated sulfuuric acid. It is a very strong oxidizing agent and a dangerous explosive when isolated. This is the actual oxidizing agent which oxidizes graphite to graphene oxide.
For some interesting information of the process please have a look at the following article which is freely available as public full text on the internet (please see attached pdf file):
Hidden Second Oxidation Step of Hummers Method
Article The Hidden Second Oxidation Step of Hummers Method
I hope this answers your question. Good luck with your work and please stay safe and healthy! With best wishes, Frank Edelmann
Dear Frank T. Edelmann I agree with you. Just a small additional comment. Sulfuric acid is a strong enough to protonate MnO4(-) to form another extremely strong oxidizer HMnO4, permanganic acid, which is volatile.
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