Talk:Uranium trioxide

Surface area

What is the surface area of a single UO₃ molecule? Should I use the diameters in Image:Uranium-trioxide-3D-vdW.png or Image:UO3.jpg? LossIsNotMore 05:12, 6 December 2006 (UTC)

It's impossible to give a single value of sufrace area for an entity that exhibits quantum mechanical behaviour, like a molecule. In that space-filling image I made, I think the surfaces enclose a volume in which the probability of finding each electron in the molecule is 90%. If you explain what calculation you are trying to do using surface area, maybe I or another chemist on WP can think of a strategy.

Ben 08:16, 6 December 2006 (UTC)

I'm trying to determine the extent that ventilation inhibits condensation, and the profile of condensation in ventilated and non-ventilated spaces. I think I need to take the van der Walls radius plus the effective radius of the solvent (which in this case is 80% N2 and 20% O2) following the method in http://www.chemcomp.com/journal/ligintdia.htm with already condensed complexes treated as coating on existing surfaces. However, that ignores spontanious condensation in air without a pre-existing surface being involved.

How would you go about predicting the condensation profile given different amounts of air movement through, say, a 10 x 10 x 10 m cube room with two opposite sides missing and an variable amount of airflow in m^3/s, and assuming a 290 g U bullet enters the room as a molten shower, with 40% of it burning, 50% of the combustion products in vapor form, and 67% of the vapor comprised of UO3(g) instead of UO2(g)?

Other assumptions would be that if it makes it out of the room, the vapor may condense on the ground (or itself) but no ceiling. After an hour, is more UO3(g) in un-condensed vapor form with a 3 m/s wind than in a completely enclosed 10 x 10 x 10 m cube room? LossIsNotMore 09:43, 12 December 2006 (UTC)

Ben, even if you can't answer the whole question, what is the appropriate surface area to use for gas reactivity statistical mechanics? LossIsNotMore 02:15, 4 January 2007 (UTC)

I think you should first read up on collision theory or perhaps buy a book on chemical kinetics. The method you linked to at chemcomp.com is more relevant to proteins and the like, in liquid and solid phases. Also, what do you mean by the term condensation profile? Read van der Waals radius, too. You may want to ask for advice at Wikipedia:WikiProject Chemistry, as condensation kinetics may, I fear, be a rather complex phenomenon.

Ben 09:10, 4 January 2007 (UTC)

Gas phase

In Carter, R.F. and K. Stewart (1970) "On the oxide fume formed by the combustion of plutonium and uranium" Inhaled Particles 2:819-38 (PMID 5527739) in particular, section (f) on page 836 indicates that about half of burning uranium goes into a gaseous vapor fume, instead of the aerosol particulates which have thus far been the only portion measured by those responsible for insuring depleted uranium munitions safety. Volatility of uranium trioxide (a/k/a uranyl oxide) gas can be plotted from Alexander (2005) and Ackermann et al. (1956), resulting in a very large DOF-adjusted R^2 corresponding to the 95% confidence interval shown. For the burning temperature of the shower-of-sparks which is the result of DU munitions use on hard targets, please see Mouradian and Baker (1963), and in particular figures 4 and 6 on page 392.

Would someone include the relevant portions of that, please? James S. 15:45, 24 January 2007 (UTC)

Mmmmm.. no, I dont think anyone will. Torturous Devastating Cudgel 20:04, 1 February 2007 (UTC)

Cytotoxic and Clastogenic

Particulate Depleted Uranium Is Cytotoxic and Clastogenic to Human Lung Cells

Depleted uranium (DU) is commonly used in military armor and munitions, and thus, exposure of soldiers and non-combatants is potentially frequent and widespread. DU is considered a suspected human carcinogen, affecting the bronchial cells of the lung. However, few investigations have studied DU in human bronchial cells. Accordingly, we determined the cytotoxicity and clastogenicity of both particulate (water-insoluble) and soluble DU in human bronchial fibroblasts (WTHBF-6 cells). We used uranium trioxide (UO3) and uranyl acetate (UA) as prototypical particulate and soluble DU salts, respectively. After a 24 h exposure, both UO3 and UA induced concentration-dependent cytotoxicity in WTHBF-6 cells. Specifically, 0.1, 0.5, 1, and 5 μg/cm2 UO3 induced 99, 57, 32, and 1% relative survival, respectively. Similarly, 100, 200, 400, and 800 M UA induced 98, 92, 70, and 56% relative survival, respectively. When treated with chronic exposure, up to 72 h, of either UO3 or UA, there was an increased degree of cytotoxicity. We assessed the clastogenicity of these compounds and found that at concentrations of 0, 0.5, 1, and 5 μg/cm2 UO3, 5, 6, 10, and 15% of metaphase cells exhibit some form of chromosome damage. UA did not induce chromosome damage above background levels. There were slight increases in chromosome damage induced when we extended the UO3 treatment time to 48 or 72 h, but no meaningful increase in chromosome damage was observed with chronic exposure to UA.

--James S. → talk 19:42, 20 June 2007 (UTC)

References

Depleted uranium is mentioned in the titles of three of the references, yet this substance is not mentioned even once in the actual text of the article. Why is this? Badagnani (talk) 08:19, 31 July 2008 (UTC)

Possible ref

I did a search at random about this topic, and found the article In vitro chemical and cellular tests applied to uranium trioxide with different hydration states from the journal Environmental Health Perspectives. I don't see it in the list of references supplied with the article, and I haven't read it to ascertain its value. (Moreover, I'm not familiar with the journal, so I can't assess its value either.) I just thought I'd post this in the event there's something useful to be gleaned from it. Mindmatrix 18:22, 9 November 2008 (UTC)

Geometry

Based on electron densities, isn't this rendering more accurate than the ball-and-stick model in the article now? 99.191.75.124 (talk) 08:10, 28 February 2010 (UTC)

That image implies that electron density is quasi-spherical and more delocalized on oxygens, which doesn't seem correct. Materialscientist (talk) 09:15, 11 March 2010 (UTC)

Amphoterism to form uranates

We see formulae like UO²⁻
₄ and U
₂O²⁻
₇ being thrown around here (presumably in analogy to Cr), despite the fact that the uranate article notes that no actual uranium oxyanions are known and that all uranates are ternary oxides. Double sharp (talk) 08:29, 6 July 2017 (UTC)