Nomenclature
CAS number: 7440-65-5
Description and references
Y; at. wt 88.90585; at. no. 39; valence 3.
Group IIIb (3). A rare earth metal. Naturally occurring isotope
(mass number): 89; known artificial radioactive isotopes: 80-88;
90-100. Estimated abundance in earth's crust: 28.1-31 ppm. Natural
sources: xenotime, fergusonite, samarskite, yttrialite, gadolinite,
and other rare earth minerals. Discovered in 1794 by Gadolin; separated
as yttria in 1843 by Mosander; named by Ekeberg. Sepn by fractional
precipitation: Bonardi, James, J. Am. Chem.
Soc. 37, 2642 (1915); Willand, James, ibid. 38, 1198 (1916); Wichers et al., ibid. 40, 1615 (1918); by ion exchange: Spedding et al., ibid. 69, 2812 (1947); Mayer,
Freiling, ibid. 75, 5647 (1953). Toxicity study:
Cochran et al., Arch. Ind. Hyg.
Occup. Med. 1, 637 (1950). Reviews of prepn,
properties and compds: The Rare Earths, F. H. Spedding, A. H. Daane, Eds. (Krieger, Huntington, N.Y., 1971,
reprint of 1961 ed.) 641 pp; Vickery, “Scandium, Yttrium and Lanthanum”,
in Comprehensive Inorganic Chemistry vol. 3, J. C. Bailar Jr. et al., Eds. (Pergamon
Press, Oxford, 1973) pp 329-353; Moeller, “The Lanthanides”, ibid. vol. 4, pp 1-101; F. H. Spedding in Kirk-Othmer Encyclopedia of Chemical Technology vol. 19 (John Wiley & Sons, New York, 3rd ed., 1982)
pp 833-854; Chemistry of the Elements N. N. Greenwood, A. Earnshaw, Eds. (Pergamon Press, New York, 1984)
pp 1102-1110, 1423-1449.
Properties
Iron-gray, lustrous powder; darkens on exposure
to light. Forms hexagonal close-packed crystals. d 4.4689. mp 1522°. bp 3338°. Heat of fusion: 11.43 kJ/mol. Heat of sublimation
(25°): 424.7 kJ/mol. E°(aq) Y3+/Y 2.37 V (calc). Oxidizes
on heating in air or oxygen; dec cold water slowly, boiling water
rapidly.Derivative
Oxide.
Nomenclature
Yttria. O
3Y
2; mol wt 225.81.
O 21.26%, Y 78.74%.
Properties
White powder, body-centered cubic structure, d 5.03. Obtained by igniting
yttrium or its salts. Sol in dil acids; readily absorbs ammonia from
the air; displaces ammonia from ammonium salts. LD50 i.p. in rats: 500 mg/kg (Cochran).Derivative
Hydroxide.
Y(OH)
3; mol wt 139.93.
Y 63.54%, O 34.30%, H 2.16%.
Properties
White gelatinous ppt, dries to a white powder
which absorbs CO2 from the air, obtained by the action
of ammonium or alkali hydroxides on a soln of an yttrium salt.Derivative
Chloride.
YCl
3; mol wt 195.26.
Y 45.53%, Cl 54.47%.
Properties
Hexahydrate, colorless, deliquesc crystals. Sol
in water, alc. Anhydr chloride obtained by heating in a stream of
HCl.Derivative
Carbonate.
Y
2(CO
3)
3; mol wt 357.84.
Y 49.69%, C 10.07%, O 40.24%.
Properties
Trihydrate, white to reddish-white powder, prepd
by hydrolysis of yttrium trichloroacetate. Insol in water. Sol in
dil mineral acids.Derivative
Sulfate.
Y
2(SO
4)
3; mol wt 466.00.
Y 38.16%, S 20.64%, O 41.20%.
Properties
Octahydrate, monoclinic crystals. Sol in concd
sulfuric acid with formation of Y(HSO4)3. Soly
in water decreases with increase in temp. Forms double salts with
alkali sulfates.Derivative
Nitrate.
Y(NO
3)
3; mol wt 274.92.
Y 32.34%, N 15.28%, O 52.38%.
Properties
Hexahydrate, deliquesc crystals, sol in water,
produces basic nitrates on partial decompn. LD50 i.p. in rats: 350 mg/kg (Cochran).Caution
Potential symptom of overexposure
to metal is eye irritation. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140,
1997) p 338.Use
Yttrium doped with rare earths as phosphors for
color television receivers. Oxide for mantles in gas and acetylene
lights. Chloride in prepn of pure metal. Yttrium aluminum garnets
(YAGS) in lasers and for making artificial diamonds.