Sodium stannate, formally sodium hexahydroxostannate(IV), is the inorganic compound with the formula Na₂ n(OH)₆ This colourless salt forms upon dissolving metallic

tin Tin is a chemical element with the symbol Sn (from la, stannum) and atomic number 50. Tin is 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, t ...

tin(IV) oxide 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 ...

in sodium hydroxide, and is used as a stabiliser for

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%� ...

. In older literature,

stannate In chemistry the term stannate 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 ...

s 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 A CAS Registry Number (also referred to as CAS RN or informally CAS Number) is a unique identification number assigned by the Chemical Abstracts Service (CAS), US to every chemical substance described in the open scientific literature. It inclu ...

, and a distinct

material safety data sheet A safety data sheet (SDS), material safety data sheet (MSDS), or product safety data sheet (PSDS) is a document that lists information relating to occupational safety and health for the use of various substances and products. SDSs are a widel ...

. Alkali metal stannate compounds are prepared by dissolving elemental tin in a suitable

metal hydroxide Metal hydroxides are hydroxides of metals. They are often strong bases. They consist of hydroxide anions and metallic cations. Some metal hydroxides, such as alkali metal hydroxides, ionize completely when dissolved. Certain metal hydroxides ar ...

, in the case of sodium stannate by the reaction: :Sn + 2 NaOH + 4 H₂O → Na₂ n(OH)₆ + 2 H₂ A similar reaction occurs when

tin dioxide 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 ...

is dissolved in base: :SnO₂ + 2 NaOH + 2 H₂O → Na₂ n(OH)₆The anhydrous form can also be prepared from tin dioxide by roasting with sodium carbonate in a mixed

carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

environment: :SnO₂ + Na₂CO₃ → Na₂SnO₃ + CO₂ The

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

is a

coordination complex A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as '' ligands'' or complexing agents. ...

that is

octahedral In geometry, an octahedron (plural: octahedra, octahedrons) is a polyhedron with eight faces. The term is most commonly used to refer to the regular octahedron, a Platonic solid composed of eight equilateral triangles, four of which meet a ...

in shape, similar to most stannates, such as the hexachlorostannate anion . The Sn—O bond distances average 2.071 Å.

References

{{Reflist Stannates Sodium compounds Hydroxides