[FabLab]

Hi

I am need of producing Chromium Monoxide and I have found the following chemical reaction which can produce it:

H3PO2 + 2 Cr2O3 → 4 CrO + H3PO4

My only problem is I don't know much about this reaction and I do not know the exact conditions ( temperature,pressure,...) required in order for it to happen and if their is any serious danger or precautions required in working with these acids. I know that H3PO2 and H3PO4 are liquid acids and that Cr2O3 is a green solid and that CrO is a black powder. What I dont know is what happens after the reaction. Does CrO deposit at the bottom of the beaker or does it dissolve in the acid? How can these two be seperated so the CrO can be used later. Also how fast is the speed of the reaction?

It's been quite a while since I have had chemistry in high school and I'm sorry if my questions might seem simple or mundane. But it would really help me if someone could give me some professional opinion on the possibility of using the mentioned reaction in order to produce Chromium Monoxide.

[SirRoderick]

First of all, I have no practical experience with this, so this is just my "feeling" here.

So H3PO2 and H3PO4 are obviously acids. Depends on the concentration you're using, but always be careful with acids, obviously. CrO is not solluble in water, so it should precipitate and you could filter it out I think. After that you might have to leave it to dry. It seems to decompose at around 300°C, so perhaps you could add some heat to help the drying, thought that might make it oxidise. (really not sure on that)

As for temperature and pressure, I find no mention of either anywhere, so it should run at room temperature in an open container without problems. I can't help you with speed, you can't really tell just like that. Shouldn't be too long if it's listed as a practical reaction for synthesis.

[Fluoroantimonicacid]

CrO is a base and I think it can react with H₃PO₄ back.