This video speaks to everyone who has ever bought anything online, or in fact, anyone who has ever bought anything period. How do you know what you're getting is genuine? Is it a fake product? Is it stolen goods? Is it impure?
Watch this science video tutorial from Nurd Rage on how to test manganese dioxide for purity (and sand) with Dr. Lithium, along with a little story of how he got RIPPED OFF!
"A particular seller on eBay is selling manganese dioxide (MnO2) that's clearly been cut with sand. NurdRage shows a simple chemical method to uncover this particular type of fraud.
Manganese dioxide will react with sulfuric acid and oxalic acid to form manganese sulfide in a quick and clean reaction. Total dissolution and a clear to pink solution is an indicator of high purity manganese dioxide. Insoluble materials or discoloration indicates the manganese dioxide may be contaminated or altered.
I'm not blaming the eBay seller himself, at least not yet. I did purchase strontium carbonate from him that turned out to be of excellent quality and let me make the "glow in the dark powder" shown in a previous video. The powder would not have worked if it wasn't extremely pure. Instead, one of his suppliers must be trying to dupe him. To bad he isn't a chemist like who can catch this sort of fraud.
Anyway, I am in contact with him and giving him a chance to make things right. I'll give him a few weeks before i start getting heavy handed.
In total, I only lost 20 bucks, so it's not like I've been put into bankruptcy by this. I'm not too angry. Now fraud is still fraud, no matter the quantity, so I'm not letting this go, but I'm not going to let this bother me, either."
Brought to you by one of WonderHowTo's favorite scientists, NurdRage.