Names | |
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IUPAC name Tin (IV) Oxide | |
Other names Stannic oxide, Tin(IV) oxide, Flowers of tin, [1] Cassiterite | |
Identifiers | |
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3D model (JSmol) |
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ChemSpider | |
ECHA InfoCard | 100.038.311 |
EC Number |
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PubChem CID | |
RTECS number |
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UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
O2Sn | |
Molar mass | 150.708 g·mol−1 |
Appearance | Yellowish or light grey powder [2] |
Odor | Odorless |
Density | 6.95 g/cm3 (20 °C) [3] 6.85 g/cm3 (24 °C) [4] |
Melting point | 1,630 °C (2,970 °F; 1,900 K) [3] [4] |
Boiling point | 1,800–1,900 °C (3,270–3,450 °F; 2,070–2,170 K) Sublimes [3] |
Insoluble [4] | |
Solubility | Soluble in hot concentrated alkalis, [4] concentrated acids Insoluble in alcohol [3] |
−4.1·10−5 cm3/mol [4] | |
Refractive index (nD) | 2.006 [5] |
Structure | |
Rutile tetragonal, tP6 [6] | |
P42/mnm, No. 136 [6] | |
4/m 2/m 2/m [6] | |
α = 90°, β = 90°, γ = 90° | |
Octahedral (Sn4+) Trigonal planar (O2−) | |
Thermochemistry | |
Heat capacity (C) | 52.6 J/mol·K [4] |
Std molar entropy (S⦵298) | 49.04 J/mol·K [4] [7] |
Std enthalpy of formation (ΔfH⦵298) | −577.63 kJ/mol [4] [7] |
Gibbs free energy (ΔfG⦵) | −515.8 kJ/mol [4] |
Hazards | |
NFPA 704 (fire diamond) | |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | > 20 g/kg (rats, oral) [8] |
NIOSH (US health exposure limits): | |
PEL (Permissible) | none [2] |
REL (Recommended) | TWA 2 mg/m3 [2] |
IDLH (Immediate danger) | N.D. [2] |
Safety data sheet (SDS) | ICSC 0954 |
Related compounds | |
Tin(II) oxide | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Tin(IV) oxide, also known as stannic oxide, is the inorganic compound with the formula SnO2. The mineral form of SnO2 is called cassiterite, and this is the main ore of tin. [9] With many other names, this oxide of tin is an important material in tin chemistry. It is a colourless, diamagnetic, amphoteric solid.
Tin(IV) oxide crystallises with the rutile structure. As such the tin atoms are six coordinate and the oxygen atoms three coordinate. [9] SnO2 is usually regarded as an oxygen-deficient n-type semiconductor. [10]
Hydrous forms of SnO2 have been described as stannic acid. Such materials appear to be hydrated particles of SnO2 where the composition reflects the particle size. [11]
Tin(IV) oxide occurs naturally. Synthetic tin(IV) oxide is produced by burning tin metal in air. [11] Annual production is in the range of 10 kilotons. [11] SnO2 is reduced industrially to the metal with carbon in a reverberatory furnace at 1200–1300 °C. [12]
Although SnO2 is insoluble in water, it is amphoteric, dissolving in base and acid. [13] "Stannic acid" refers to hydrated tin (IV) oxide, SnO2, which is also called "stannic oxide."
Tin oxides dissolve in acids. Halogen acids attack SnO2 to give hexahalostannates, [14] such as [SnI6]2−. One report describes reacting a sample in refluxing HI for many hours. [15]
Similarly, SnO2 dissolves in sulfuric acid to give the sulfate: [11]
SnO2 dissolves in strong bases to give "stannates," with the nominal formula Na2SnO3. [11] Dissolving the solidified SnO2/NaOH melt in water gives Na2[Sn(OH)6], "preparing salt," which is used in the dye industry. [11]
In conjunction with vanadium oxide, it is used as a catalyst for the oxidation of aromatic compounds in the synthesis of carboxylic acids and acid anhydrides. [9]
Tin(IV) oxide has long been used as an opacifier and as a white colorant in ceramic glazes.’The Glazer’s Book’ – 2nd edition. A.B.Searle.The Technical Press Limited. London. 1935. This has probably led to the discovery of the pigment lead-tin-yellow, which was produced using tin(IV) oxide as a compound. [16] The use of tin(IV) oxide has been particularly common in glazes for earthenware, sanitaryware and wall tiles; see the articles tin-glazing and Tin-glazed pottery. Tin oxide remains in suspension in vitreous matrix of the fired glazes, and, with its high refractive index being sufficiently different from the matrix, light is scattered, and hence increases the opacity of the glaze. The degree of dissolution increases with the firing temperature, and hence the extent of opacity diminishes. [17] Although dependent on the other constituents the solubility of tin oxide in glaze melts is generally low. Its solubility is increased by Na2O, K2O and B2O3, and reduced by CaO, BaO, ZnO, Al2O3, and to a limited extent PbO. [18]
SnO2 has been used as pigment in the manufacture of glasses, enamels and ceramic glazes. Pure SnO2 gives a milky white colour; other colours are achieved when mixed with other metallic oxides e.g. V2O5 yellow; Cr2O3 pink; and Sb2O5 grey blue. [11]
This oxide of tin has been utilized as a mordant in the dyeing process since ancient Egypt. [19] A German by the name of Kuster first introduced its use to London in 1533 and by means of it alone, the color scarlet was produced there. [20]
Tin(IV) oxide can be used as a polishing powder, [11] sometimes in mixtures also with lead oxide, for polishing glass, jewelry, marble and silver. [1] Tin(IV) oxide for this use is sometimes called as "putty powder" [13] or "jeweler's putty". [1]
SnO2 coatings can be applied using chemical vapor deposition, vapour deposition techniques that employ SnCl4 [9] or organotin trihalides [21] e.g. butyltin trichloride as the volatile agent. This technique is used to coat glass bottles with a thin (<0.1 μm) layer of SnO2, which helps to adhere a subsequent, protective polymer coating such as polyethylene to the glass. [9]
Thicker layers doped with Sb or F ions are electrically conducting and used in electroluminescent devices and photovoltaics. [9]
SnO2 is used in sensors of combustible gases including carbon monoxide detectors. In these the sensor area is heated to a constant temperature (few hundred °C) and in the presence of a combustible gas the electrical resistivity drops. [22] Room temperature gas sensors are also being developed using reduced graphene oxide-SnO2 composites(e.g. for ethanol detection). [23]
Doping with various compounds has been investigated (e.g. with CuO [24] ). Doping with cobalt and manganese, gives a material that can be used in e.g. high voltage varistors. [25] Tin(IV) oxide can be doped with the oxides of iron or manganese. [26]
Tin is a chemical element; it has symbol Sn and atomic number 50. A silvery-coloured metal, tin is soft enough to be cut with little force, and a bar of tin can be bent by hand with little effort. When bent, the so-called "tin cry" can be heard as a result of twinning in tin crystals; this trait is shared by indium, cadmium, zinc, and mercury in its solid state.
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula SiO2, commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is abundant as it comprises several minerals and synthetic products. All forms are white or colorless, although impure samples can be colored.
In chemistry, an amphoteric compound is a molecule or ion that can react both as an acid and as a base. What exactly this can mean depends on which definitions of acids and bases are being used.
Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions held together by ionic bonding. Magnesium hydroxide forms in the presence of water (MgO + H2O → Mg(OH)2), but it can be reversed by heating it to remove moisture.
Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO), which is rare; and iron(II,III) oxide (Fe3O4), which also occurs naturally as the mineral magnetite. As the mineral known as hematite, Fe2O3 is the main source of iron for the steel industry. Fe2O3 is readily attacked by acids. Iron(III) oxide is often called rust, since rust shares several properties and has a similar composition; however, in chemistry, rust is considered an ill-defined material, described as hydrous ferric oxide.
Barium nitrate is the inorganic compound with the chemical formula Ba(NO3)2. It, like most barium salts, is colorless, toxic, and water-soluble. It burns with a green flame and is an oxidizer; the compound is commonly used in pyrotechnics.
An opacifier is a substance added to a material in order to make the ensuing system opaque. An example of a chemical opacifier is titanium dioxide (TiO2), which is used as an opacifier in paints, in paper, and in plastics. It has very high refraction index (rutile modification 2.7 and anatase modification 2.55) and optimum refraction is obtained with crystals about 225 nanometers. Impurities in the crystal alter the optical properties. It is also used to opacify ceramic glazes and milk glass; bone ash is also used.
Tin(IV) chloride, also known as tin tetrachloride or stannic chloride, is an inorganic compound with the formula SnCl4. It is a colorless hygroscopic liquid, which fumes on contact with air. It is used as a precursor to other tin compounds. It was first discovered by Andreas Libavius (1550–1616) and was known as spiritus fumans libavii.
In chemistry, the term stannate or tinnate refers to compounds of tin (Sn). Stannic acid (Sn(OH)4), the formal precursor to stannates, does not exist and is actually a hydrate of SnO2. The term is also used in naming conventions as a suffix; for example the hexachlorostannate ion is SnCl2−
6.
Tungsten(VI) oxide, also known as tungsten trioxide is a chemical compound of oxygen and the transition metal tungsten, with formula WO3. The compound is also called tungstic anhydride, reflecting its relation to tungstic acid H2WO4. It is a light yellow crystalline solid.
In materials science, the sol–gel process is a method for producing solid materials from small molecules. The method is used for the fabrication of metal oxides, especially the oxides of silicon (Si) and titanium (Ti). The process involves conversion of monomers into a colloidal solution (sol) that acts as the precursor for an integrated network of either discrete particles or network polymers. Typical precursors are metal alkoxides. Sol–gel process is used to produce ceramic nanoparticles.
Stibine (IUPAC name: stibane) is a chemical compound with the formula SbH3. A pnictogen hydride, this colourless, highly toxic gas is the principal covalent hydride of antimony, and a heavy analogue of ammonia. The molecule is pyramidal with H–Sb–H angles of 91.7° and Sb–H distances of 170.7 pm (1.707 Å). This gas has an offensive smell like hydrogen sulfide (rotten eggs).
Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being the principal precursor to alloys of vanadium and is a widely used industrial catalyst.
Tin(II) chloride, also known as stannous chloride, is a white crystalline solid with the formula SnCl2. It forms a stable dihydrate, but aqueous solutions tend to undergo hydrolysis, particularly if hot. SnCl2 is widely used as a reducing agent (in acid solution), and in electrolytic baths for tin-plating. Tin(II) chloride should not be confused with the other chloride of tin; tin(IV) chloride or stannic chloride (SnCl4).
Antimony(III) oxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite. Like most polymeric oxides, Sb2O3 dissolves in aqueous solutions with hydrolysis. A mixed arsenic-antimony oxide occurs in nature as the very rare mineral stibioclaudetite.
Tin(II) oxide is a compound with the formula SnO. It is composed of tin and oxygen where tin has the oxidation state of +2. There are two forms, a stable blue-black form and a metastable red form.
Tin-glazing is the process of giving tin-glazed pottery items a ceramic glaze that is white, glossy and opaque, which is normally applied to red or buff earthenware. Tin-glaze is plain lead glaze with a small amount of tin oxide added. The opacity and whiteness of tin glaze encourage its frequent decoration. Historically this has mostly been done before the single firing, when the colours blend into the glaze, but since the 17th century also using overglaze enamels, with a light second firing, allowing a wider range of colours. Majolica, maiolica, delftware and faience are among the terms used for common types of tin-glazed pottery.
Beryllium hydroxide, Be(OH)2, is an amphoteric hydroxide, dissolving in both acids and alkalis. Industrially, it is produced as a by-product in the extraction of beryllium metal from the ores beryl and bertrandite. The natural pure beryllium hydroxide is rare (in form of the mineral behoite, orthorhombic) or very rare (clinobehoite, monoclinic). When alkali is added to beryllium salt solutions the α-form (a gel) is formed. If this left to stand or boiled, the rhombic β-form precipitates. This has the same structure as zinc hydroxide, Zn(OH)2, with tetrahedral beryllium centers.
Indium(III) oxide (In2O3) is a chemical compound, an amphoteric oxide of indium.
Stannosis is an occupational, non-fibrotic pneumoconiosis caused by chronic exposure and inhalation of tin. Pneumoconiosis is essentially when inorganic dust is found on the lung tissue; in this case, caused by tin oxide minerals. Dust particles and fumes from tin industries, stannous oxide (SnO) and stannic oxide (SnO2), are specific to stannosis diagnoses. Hazardous occupations such as, tinning, tin-working, and smelting are where most cases of stannosis are documented. When melted tin ions are inhaled as a fume, the tin oxides deposit onto the lung nodules and immune response cells. If a worker is exposed to tin oxides over multiple events for an extended time, they are at risk of developing stannosis.