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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: interminable on February 06, 2010, 01:19:26 AM

Title: Balanced Equation for Synthesis of Vanadyl Acetylacetonate
Post by: interminable on February 06, 2010, 01:19:26 AM

So in my next experiment, I'm going to be preparing VO(acac)2 from V2O5, sulfuric acid, acetylacetone, followed by neutralizing with sodium carbonate.

I've been attempting to figure out the overall equation. I've figured out that the Vanadium is reduced:
VO₂⁺ + 2H⁺ + e-  :rarrow: VO²⁺ + H₂O

The only thing I could see being potentially oxidized is the sulfur in sulfuric acid, so from a table I got:
2[SO₄]^2-  :rarrow: [S₂O₈]^2- + 2e-

Giving overall:
2VO₂⁺ + 4H⁺ + 2[SO₄]^2-  :rarrow: 2VO²⁺ + 2H₂O + [S₂O₈]^2-

I'm stuck with figuring out how to write this in terms of the full compounds being used rather than the ions. (i.e. V2O5 + H2SO4)
I think the main part throwing me off is that there's an extra oxygen in V2O5 that I can't figure out what to do with. Then there's the H's from the acacH too.

I found an equation on page 2 of this pdf:
http://www.chemistry.ucsc.edu/~soliver/151L/Expt3Refs1.pdf
But these show the vanadium being reduced from V to IV, and I don't see anything being oxidized.

I've also found this website:
http://course1.winona.edu/cmiertschin/450/Lab/Acac_lab.pdf
Which suggests that H2 is what's being oxidized - but I don't even see a source of it.

I'm also curious because the procedure mentions that the mixture may froth over (when we're just mixing the V2O5 and sulfuric acid), and I'd assume a gas is causing this, but I can't see how it's being formed.

Any help, especially with the equation, would be appreciated. Thank you.