Tin(II) oxide

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Tin(II) oxide
PbO structure.png
Tin(II) oxide.jpg
Tin(II) oxide hydrate (2).JPG
IUPAC name
Tin(II) oxide
Other names
Stannous oxide
Tin monoxide
3D model (JSmol)
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EC Number
  • 244-499-5
PubChem CID
RTECS number
  • XQ3700000
  • InChI=1S/O.Sn
  • O=[Sn]
Molar mass 134.709 g/mol
Appearanceblack or red powder when anhydrous, white when hydrated
Density 6.45 g/cm3
Melting point 1,080 °C (1,980 °F; 1,350 K) [1]
19.0·10−6 cm3/mol
Std molar
56 J·mol−1·K−1 [2]
−285 kJ·mol−1 [2]
Flash point Non-flammable
NIOSH (US health exposure limits):
PEL (Permissible)
none [3]
REL (Recommended)
TWA 2 mg/m3 [3]
IDLH (Immediate danger)
N.D. [3]
Safety data sheet (SDS) ICSC 0956
Related compounds
Other anions
Tin sulfide
Tin selenide
Tin telluride
Other cations
Carbon monoxide
Silicon monoxide
Germanium(II) oxide
Lead(II) oxide
Related tin oxides
Tin dioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Tin(II) oxide (stannous 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.


Preparation and reactions

Tin(II) oxide burning Tin(II) oxide burning.JPG
Tin(II) oxide burning

Blue-black SnO can be produced by heating the tin(II) oxide hydrate, SnO·xH2O (x<1) precipitated when a tin(II) salt is reacted with an alkali hydroxide such as NaOH. [4]
Metastable, red SnO can be prepared by gentle heating of the precipitate produced by the action of aqueous ammonia on a tin(II) salt. [4]
SnO may be prepared as a pure substance in the laboratory, by controlled heating of tin(II) oxalate (stannous oxalate) in the absence of air or under a CO2 atmosphere. This method is also applied to the production of ferrous oxide and manganous oxide. [5] [6]

SnC2O4·2H2O → SnO + CO2 + CO + 2 H2O

Tin(II) oxide burns in air with a dim green flame to form SnO2. [4]

2 SnO + O2 → 2 SnO2

When heated in an inert atmosphere initially disproportionation occurs giving Sn metal and Sn3O4 which further reacts to give SnO2 and Sn metal. [4]

4SnO → Sn3O4 + Sn
Sn3O4 → 2SnO2 + Sn

SnO is amphoteric, dissolving in strong acid to give tin(II) salts and in strong base to give stannites containing Sn(OH)3. [4] It can be dissolved in strong acid solutions to give the ionic complexes Sn(OH2)32+ and Sn(OH)(OH2)2+, and in less acid solutions to give Sn3(OH)42+. [4] Note that anhydrous stannites, e.g. K2Sn2O3, K2SnO2 are also known. [7] [8] [9] SnO is a reducing agent and is thought to reduce copper(I) to metallic clusters in the manufacture of so-called "copper ruby glass". [10]


Black, α-SnO adopts the tetragonal PbO layer structure containing four coordinate square pyramidal tin atoms. [11] This form is found in nature as the rare mineral romarchite. [12] The asymmetry is usually simply ascribed to a sterically active lone pair; however, electron density calculations show that the asymmetry is caused by an antibonding interaction of the Sn(5s) and the O(2p) orbitals. [13] The electronic structure and chemistry of the lone pair determines most of the properties of the material. [14]

Non-stoichiometry has been observed in SnO. [15]

The electronic band gap has been measured between 2.5eV and 3eV. [16]


The dominant use of stannous oxide is as a precursor in manufacturing of other, typically divalent, tin compounds or salts. Stannous oxide may also be employed as a reducing agent and in the creation of ruby glass. [17] It has a minor use as an esterification catalyst.

Cerium(III) oxide in ceramic form, together with Tin(II) oxide (SnO) is used for illumination with UV light. [18]

Related Research Articles

<span class="mw-page-title-main">Tin</span> Chemical element, symbol Sn and atomic number 50

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.

Sulfur trioxide (alternative spelling sulphur trioxide, also known as nisso sulfan) is the chemical compound with the formula SO3. It has been described as "unquestionably the most important economically" sulfur oxide. It is prepared on an industrial scale as a precursor to sulfuric acid.

Cuprates are a class of compounds that contain copper (Cu). They can be broadly categorized into two main types:

<span class="mw-page-title-main">Lead(II) chloride</span> Chemical compound

Lead(II) chloride (PbCl2) is an inorganic compound which is a white solid under ambient conditions. It is poorly soluble in water. Lead(II) chloride is one of the most important lead-based reagents. It also occurs naturally in the form of the mineral cotunnite.

<span class="mw-page-title-main">Copper(II) oxide</span> Chemical compound – an oxide of copper with formula CuO

Copper(II) oxide or cupric oxide is an inorganic compound with the formula CuO. A black solid, it is one of the two stable oxides of copper, the other being Cu2O or copper(I) oxide (cuprous oxide). As a mineral, it is known as tenorite. It is a product of copper mining and the precursor to many other copper-containing products and chemical compounds.

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−

<span class="mw-page-title-main">Tin(II) chloride</span> Chemical compound

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).

<span class="mw-page-title-main">Tin(IV) oxide</span> Chemical compound known as stannic oxide, cassiterite and tin ore

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. With many other names, this oxide of tin is an important material in tin chemistry. It is a colourless, diamagnetic, amphoteric solid.

Octahedral clusters are inorganic or organometallic cluster compounds composed of six metals in an octahedral array. Many types of compounds are known, but all are synthetic.

<span class="mw-page-title-main">Tin(II) hydroxide</span> Chemical compound

Tin(II) hydroxide, Sn(OH)2, also known as stannous hydroxide, is an inorganic compound tin(II). The only related material for which definitive information is available is the oxy hydroxide Sn6O4(OH)4, but other related materials are claimed. They are all white solids that are insoluble in water.

<span class="mw-page-title-main">Lanthanum oxide</span> Chemical compound

Lanthanum(III) oxide, also known as lanthana, chemical formula La2O3, is an inorganic compound containing the rare earth element lanthanum and oxygen. It is used in some ferroelectric materials, as a component of optical materials, and is a feedstock for certain catalysts, among other uses.

<span class="mw-page-title-main">Cobalt(II) oxide</span> Chemical compound

Cobalt(II) oxide is an inorganic compound that has been described as an olive-green or gray solid. It is used extensively in the ceramics industry as an additive to create blue-colored glazes and enamels, as well as in the chemical industry for producing cobalt(II) salts. A related material is cobalt(II,III) oxide, a black solid with the formula Co3O4.

Germanium dioxide, also called germanium(IV) oxide, germania, and salt of germanium, is an inorganic compound with the chemical formula GeO2. It is the main commercial source of germanium. It also forms as a passivation layer on pure germanium in contact with atmospheric oxygen.

<span class="mw-page-title-main">Tin(II) fluoride</span> Chemical compound

Tin(II) fluoride, commonly referred to commercially as stannous fluoride (from Latin stannum, 'tin'), is a chemical compound with the formula SnF2. It is a colourless solid used as an ingredient in toothpastes.

<span class="mw-page-title-main">Manganese(II) oxide</span> Chemical compound

Manganese(II) oxide is an inorganic compound with chemical formula MnO. It forms green crystals. The compound is produced on a large scale as a component of fertilizers and food additives.

<span class="mw-page-title-main">Californium compounds</span>

Few compounds of californium have been made and studied. The only californium ion that is stable in aqueous solutions is the californium(III) cation. The other two oxidation states are IV (strong oxidizing agents) and II (strong reducing agents). The element forms a water-soluble chloride, nitrate, perchlorate, and sulfate and is precipitated as a fluoride, oxalate or hydroxide. If problems of availability of the element could be overcome, then CfBr2 and CfI2 would likely be stable.

<span class="mw-page-title-main">Sodium stannate</span> Chemical compound

Sodium stannate, formally sodium hexahydroxostannate(IV), is the inorganic compound with the formula Na2[Sn(OH)6]. This colourless salt forms upon dissolving metallic tin or tin(IV) oxide in sodium hydroxide, and is used as a stabiliser for hydrogen peroxide. In older literature, stannates are sometimes represented as having the simple oxyanion SnO32−, in which case this compound is sometimes named as sodium stannate–3–water and represented as Na2SnO3·3H2O, a hydrate with three waters of crystallisation. The anhydrous form of sodium stannate, Na2SnO3, is recognised as a distinct compound with its own CAS Registry Number, 12058-66-1, and a distinct material safety data sheet.

<span class="mw-page-title-main">Post-transition metal</span> Category of metallic elements

The metallic elements in the periodic table located between the transition metals to their left and the chemically weak nonmetallic metalloids to their right have received many names in the literature, such as post-transition metals, poor metals, other metals, p-block metals and chemically weak metals. The most common name, post-transition metals, is generally used in this article.

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.

<span class="mw-page-title-main">Tin(II) oxalate</span> Chemical compound

Tin(II) oxalate is an inorganic compound, a salt of tin and oxalic acid with the chemical formula SnC
. The compound looks like colorless crystals, does not dissolve in water, and forms crystalline hydrates.


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