sternman318 - 25-5-2011 at 14:46
Well, long story short, I have some potassium dichromate that my teacher is allowing me to do some chemistry with. So far, I managed to create some
Cr(III)+ via
1) adding magnesium to an acidified solution of potassium dichromate
but did some research and found a much better/cleaner method, which is to use
2) hydrogen peroxide
Are there any reactions that would be of interest, using either Cr(III)+ or potassium dichromate? Or any salts/compounds I could make that would make
nice samples? I have found this website ( http://www.chemguide.co.uk/inorganic/transition/chromium.htm...) which has a lot of interesting bits about the coordination chemistry of it, but I
don't nearly have enough time to do most of them. However, the creation of chrome alum seems expecially interesting, so I might give that a shot.
ScienceSquirrel - 25-5-2011 at 15:42
Some good chromium chemistry could include;
1) Chrome alum, easy and really beautiful crystals and there are recipes on the internet.
2) Chromium II acetate. Mildly air sensitive with a metal metal quadruple bond
http://www.sciencemadness.org/talk/viewthread.php?tid=16289#...
http://en.wikipedia.org/wiki/Chromium_acetate
3) Chromium peroxide
If you mix a dichromate solution with hydrogen peroxide and sulphuric acid it goes blue and then green and oxygen is evolved.
If you do it in the presence of diethyl ether the ether turns blue and can be removed with a pipette, dried over magnesium sulphate and then
evaporated to give bright blue needles of the peroxide etherate.
http://en.wikipedia.org/wiki/Chromium_peroxide
Wizzard - 26-5-2011 at 08:11
Chrome alum crystals get my vote 
Pretty, easy to make large, and safe to handle
and stable in air.