Chromium chlorate

Chromium(iii) chlorate is a slightly soluble inorganic salt with the formula Cr(ClO3)3. I chose to make some chromium chlorate because I could find almost no information on it and I was curious about what it would be like.

 I knew copper(ii) chlorate was very soluble, so I thought chromium(ii) chlorate would be as well. I tried adding a solution of chromium(ii) sulphate to a solution of calcium chlorate. I hoped that calcium sulphate would precipitate and I would be left with a chromium(ii) chlorate solution. A precipitate did form, but it was a blue-green color so I knew it couldn't be purely calcium sulphate.

I decided to give chromium(ii) chlorate a break and try making chromium(iii) chlorate.

I prepared a chromium(iii) chloride solution and to it I added a solution of calcium chlorate. A navy blue precipitate of chromium(iii) chlorate formed! The same precipitate formed when sodium chlorate was used in place of calcium chlorate. Anyway I filtered off the chromium(iii) chlorate and dried it. Success!












left = dried chromium(iii) chlorate / right = pyrotechnic with chromium(iii) chlorate and Mg
2 CrCl3 + 3 Ca(ClO3)2 ==> 3 CaCl2 + 2 Cr(ClO3)3