Valentinite

Valentinite, see Antimony(III) oxide Verdigris, see Copper acetate hydrate Vermillion, see Mercury(II) sulflde Villiaumite, see Sodium fluoride Vitamin B3, see Calcium (+)pantothenate Washing soda, see Sodium carbonate 10-water Whitlockite, see Calcium phosphate Willemite, see Zinc silicate(4—)... 

Antimony Trioxide. Antimony(III) oxide (antimony sesquioxide) [1309-64-4] Sb203, is dimorphic, existing in an orthorhombic modification valentinite [1317-98-2] is colorless (sp gr 5.67) and exists in a cubic form and senarmontite [12412-52-17, Sb O, is also colorless (sp gr 5.2). The cubic modification is stable at temperatures below 570°C and consists of discrete Sb O molecules. The molecule is similar to that of P40 and As O and consists of a bowed tetrahedron having antimony atoms at each corner united by oxygen atoms lying in front of the edges. This solid crystallizes in a diamond lattice with an Sb O molecule at each carbon position. 

At higher temperatures the stable form is valentinite, which consists of infinite double chains. The orthorhombic modification is metastable below 570 °C however, it is sufficientiy stable to exist as a mineral. Antimony trioxide melts in the absence of oxygen at 656°C and partially sublimes before reaching the boiling temperature, 1425°C. The vapor at 1500°C consists largely of Sb O molecules, but these dissociate at higher temperatures to form Sb202 molecules. 

Chemical Designations - Synonyms Diantimony Trioxide Exitelite Flowers of antimony Senarmontite Valentinite Weisspiessglanz Chemical Formula SbjOj. 

Spiessglanz-asche, /. antimony ash. -bleierz, n. bournonite. -blende, /, antimony blende, kermesite. -blumen, /.pi. flowers of antimony. -butter, /. butter of antimony (old name for antimony trichloride), -erz, n. antimony ore (graues, stibnite schwarzes, bournonite weisses, valentinite), - las, n. glass of antimony. 

Weiss-siedlauge, /. blanching liquor, -spiess-glanz, m., -spiessglanzerz, n. white antimony, valentinite. -stein, m. white stone or rock (Copper) white metal, -strahl, m., -strahl-elsen, n. white pig iron resembling spiegel-eisen. 

Antimony occurs in nature primarily in the mineral stibnite, and also in several other ores, such as valentinite, senarmontite, cervantite, kermasite, hvingstonite, and jamisonite. It is also found in lead scraps from batteries. 

Antimony trioxide occurs in nature as minerals, valentinite [1317-98-2] and senarmontinite [12412-52-1]. It is used as a flame retardant in fabrics as an opacifier in ceramics, glass and vitreous enamels as a catalyst as a white pigment in paints as a mortar in the manufacture of tartar emetic and in the production of metallic antimony. 

Occurs as colorless orthorhombic modifications, valentinite, or colorless cubic form, senarmontite density 5.67 g/cm (valentinite), 5.20g/cm3 (senar-montite) cubic modification is dimeric consisting of Sb20e discrete molecules refractive index 2.087 melts in the absence of oxygen at 656°C boils at 1,550°C (sublimes) sublimes in vacuum at 400°C very slightly soluble in water, insoluble in organic solvents soluble in HCl, caustic alkalies and tartaric acid. 

The trioxides of arsenic, antimony and bismuth are of structural interest, showing a transition from the molecular lattice characteristic of covalent compounds to an ionic lattice. Arsenic oxide contains As Og molecules, similar in structure to P40g and based on the As tetrahedron. The cubic form of Sb Og is similar, but above 570° this is converted to the macro-molecular valentinite form containing infinite chains (Fig. 179). 

The second form of antimony trioxide, valentinite, has a different type of structure. Instead of finite molecules Sb40e there are infinite double chains of the type shown below, with Sb-0, 2-00 A, 0 bond angles of 116° and 132°, and Sb bond angles of 81°, 93°, and 99°. 

---