Uranyl acetate

Uranyl acetate

Uranyl acetate
200px Structure of dihydrate
Names
IUPAC name Uranium bis(acetato)-O)dioxo-dihydrate
Other names Uranyl ethanoate ; Uranyl acetate dihydrate
Identifiers
CAS Number	541-09-3 (anhydrous) Y 6159-44-0 (dihydrate) N
Properties
Chemical formula	UO2(CH3COO)2 (anhydrous) UO2(CH3COO)2·2H2O (dihydrate)
Molar mass	424.146 g/mol (dihydrate)
Appearance	yellow-green crystals (dihydrate)
Density	2.89 g/cm3 (dihydrate)
Melting point	decomposes at 80 °C (dihydrate)
Solubility	slightly soluble in ethanol
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Uranyl acetate (UO₂(CH₃COO)₂·2H₂O) is the acetate salt of uranyl and is a yellow-green crystalline solid made up of yellow-green rhombic crystals and has a slight acetic odor. Uranyl acetate is slightly radioactive, the precise radioactivity depends on the isotopes of uranium present. This compound is a nuclear fuel derivative, and its use and possession are sanctioned by international law.

Production

Commercial preparations of uranyl acetate are usually made from depleted uranium and are prepared by reacting metallic uranium with acetic acid.

Uses

250px

Uranyl magnesium acetate under visible light

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Uranyl magnesium acetate under UV light

Uranyl acetate is extensively used as a negative stain in electron microscopy. Most procedures in electron microscopy for biology require the use of uranyl acetate. Negative staining protocols typically treat the sample with 1% to 5% aqueous solution. Uranyl acetate staining is simple and quick to perform and one can examine the sample within a few minutes after staining. Some biological samples are not amenable to uranyl acetate staining and, in these cases, alternative staining techniques and or low-voltage electron microscopy technique may be more suitable.

1% and 2% uranyl acetate solutions are used as an indicator, and a titrant in stronger concentrations in analytical chemistry, as it forms an insoluble salt with sodium (the vast majority of sodium salts are water-soluble). Uranyl acetate solutions show evidence of being sensitive to light, especially UV, and will precipitate if exposed.

Uranyl acetate is also used in a standard test—American Association of State Highway and Transportation Officials (AASHTO) Designation T 299—for alkali-silica reactivity in aggregates (crushed stone or gravel) being considered for use in cement concrete.

Safety

Uranyl acetate is both radioactive and toxic. Normal commercial stocks prepared from depleted uranium have a typical specific activity of 0.37–0.51 microcuries (14–19 kBq) per gram. This is a very mild level of radioactivity and is not sufficient to be harmful while the material remains external to the body.

Uranyl acetate is very toxic if ingested, inhaled as dust or by skin contact if skin is cut or abraded. The toxicity is due to the combined effect of chemical toxicity and mild radioactivity and there is a danger of cumulative effects from long term exposure.

External links

• Uranium Facts

Salts and the ester of the Acetate ion
AcOH																	He
LiOAc	Be(OAc)2 BeAcOH											B(OAc)3	ROAc	NH4OAc	AcOAc	FAc	Ne
NaOAc	Mg(OAc)2											Al(OAc)3 ALSOL Al(OAc)2OH	Si	P	S	ClAc	Ar
KOAc	Ca(OAc)2	Sc(OAc)3	Ti(OAc)4	VO(OAc)3	Cr(OAc)2	Mn(OAc)2 MnAc3	Fe(OAc)2 FeAc3	Co(OAc)2, CoAc3	Ni(OAc)2	Cu(OAc)2	Zn(OAc)2	Ga(OAc)3	Ge	As	Se	BrAc	Kr
RbOAc	Sr(OAc)2	Y(OAc)3	Zr(OAc)4	Nb	Mo(OAc)2	Tc	Ru(OAc)2 Ru(OAc)3 Ru(OAc)4	Rh2(OAc)4	Pd(OAc)2	AgOAc	Cd(OAc)2	In	Sn(OAc)2 SnAc4	Sb(OAc)3	Te	IAc	Xe
CsOAc	Ba(OAc)2		Hf	Ta	W	Re	Os	Ir	Pt(OAc)2	Au	Hg2(OAc)2, HgAc2	TlOAc Tl(OAc)3	Pb(OAc)2 Pb(OAc)4	Bi(OAc)3	Po	At	Rn
Fr	Ra		Rf	Db	Sg	Bh	Hs	Mt	Ds	Rg	Cn	Uut	Fl	Uup	Lv	Uus	Uuo
		↓
		La(OAc)3	Ce(OAc)x	Pr	Nd	Pm	Sm(OAc)3	Eu(OAc)3	Gd(OAc)3	Tb	Dy(OAc)3	Ho(OAc)3	Er	Tm	Yb(OAc)3	Lu(OAc)3
		Ac	Th	Pa	UO2(OAc)2	Np	Pu	Am	Cm	Bk	Cf	Es	Fm	Md	No	Lr