Sciencemadness Discussion Board

black Fe2O3?

Blackout - 2-5-2005 at 13:53

Unfortunately, I didn't weight the reagents...
To a small glass jar containing Fe2O3 (red-brown), I add 3% H2O2. Evolution of heat and dioxygen was noticed. After about one week keeping the stuff under water, it turn slowly black. After drying, I test the black powder with a small magnet, the test was positive. I would have believed that it was Fe3O4 but Fe2O3 is to stable to react with H2O2. What did I made??

12AX7 - 2-5-2005 at 17:19

Hm, that is rather odd. Fe3O4 (or iron even) would have to be reduction, not something that happens much with H2O2!

Maybe it just corroded it in some way that it's microscopically black, rather than black in color?

Tim

azaleaemerson - 3-5-2005 at 04:33

Yeah, very tiny particles of rust are black in color. Do a search on magnetic fluids and you'll see some very cool black liquids. They are made of precipitated rust suspended in oil.

Jettin4u - 1-7-2005 at 08:58

You probably turned Fe2O3 into Fe3O4 which is insoluble in water and is black and has a metallic luster with magnetic properties

uber luminal - 1-7-2005 at 15:23

Fe304 is magnetic and since its black... This should probably answer your question.

The magnetic fluids are made not with rust, but with Fe3O4 or powdered Fe. (FerroFluid)

Fe2O3 can be magnetic if activated or held at a certain temp, but I dont think its magnetic in normal conditions.

Jettin4u - 3-7-2005 at 19:13

umm, thats what i said :)

IrC - 3-7-2005 at 19:53

This link has good information on liquid magnets:

http://www.sci-spot.com/Chemistry/liqimag.htm

How cool

chloric1 - 4-7-2005 at 12:06

Hey all you need is oleic acid from one of those candle/soap making suppliers and some kerosene. You can read more at about.com