Australia's Science Forum

Help. We have been burning Magnesium ribbon in a crucible for years to make a compound but the last few years we have had trouble getting in to burn. We had it going for 2 hours and only 1 worked. Any hints?

Perhaps the Magnesium ribbon, has a coating on it? We would get the students to clean it with steel wool.

If its black stuff ,I remove it by pulling a length through folded sand paper . A couple of pulls and its gone .

Probably stating the obvious , but when you heat it in the crucible , the lid should be on . Then when you lift the lid ( with tongs) , it lets in fresh oxygen and bursts into flames .

Also , I'm not sure if this is a problem for you ,but I always try to clean the crucibles after use by soaking them in HCl to remove the crud that forms in the bottom .

Thanks. It never used to be a problem, so although we clean the Mg I will get them to clean it 100% and I put out new crucibles but still didn't get a powder but a couple at least burnt the Mg a fair bit and got a slight weight increase.