Sodium aluminosilicate is an acid salt

Acid salt

Acid salt is a somewhat obscure term for a class of salts formed by the partial neutralization of diprotic or polyprotic acids. Because the parent acid is only partially neutralized, one or more replaceable hydrogen atoms remain. Typical acid salts have one or more alkali metal ions as well as one...

 comprising sodium

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...

, aluminium

Aluminium

Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

, silicon

Silicon

Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...

 and oxygen

Oxygen

Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

. These include synthetic amorphous sodium aluminosilicate, a few naturally occurring minerals and synthetic zeolite

Zeolite

Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. The term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that upon rapidly heating the material stilbite, it produced large amounts of steam from water that...

s. Synthetic amorphous sodium aluminosilicate is widely used as a food additive, E-554

E number

E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...

.

Amorphous sodium aluminosilicate

This substance is produced with a wide range of compositions and has many different applications. It is encountered as an additive E-554

E number

E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...

 in food where it acts as an anticaking

Anticaking agent

An anticaking agent is an additive placed in powdered or granulated materials, such as table salt, to prevent the formation of lumps, easing packaging, transport, and consumption....

 (free flow) agent.

As it is manufactured with a range of compositions (see http://www.chem.unep.ch/irptc/sids/oecdsids/Silicates.pdf and so is not strictly a chemical compound with a fixed stoichiometry, one supplier ( http://www.rhodia-silicas.com/markets/datasheets/T17.pdf ) quotes a typical analysis for one of their products as 14SiO₂.Al₂O₃.Na₂O.3H₂O,( Na₂Al₂Si₁₄ O₃₂.3H₂O).


Sodium aluminosilicate may also be listed as:

• aluminium sodium salt,
• sodium silicoaluminate,
• aluminosilicic acid, sodium salt,
• sodium aluminium silicate,
• aluminum sodium silicate
• sodium silico aluminate
• sasil

Minerals

Naturally occurring minerals which are sometimes given the chemical name, sodium aluminosilicate include albite

Albite

Albite is a plagioclase feldspar mineral. It is the sodium endmember of the plagioclase solid solution series. As such it represents a plagioclase with less than 10% anorthite content. The pure albite endmember has the formula NaAlSi3O8. It is a tectosilicate. Its color is usually pure white, hence...

 (NaAlSi₃O₈, an end-member of the plagioclase

Plagioclase

Plagioclase is an important series of tectosilicate minerals within the feldspar family. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a solid solution series, more properly known as the plagioclase feldspar series...

 series) and jadeite

Jadeite

Jadeite is a pyroxene mineral with composition NaAlSi2O6. It is monoclinic. It has a Mohs hardness of about 6.5 to 7.0 depending on the composition. The mineral is dense, with a specific gravity of about 3.4. Jadeite forms solid solutions with other pyroxene endmembers such as augite and diopside ,...

(NaAlSi₂O₆).

Synthetic zeolites

Synthetic zeolites have complex structures and examples (with structural formulae) are:

Na₁₂Al₁₂Si₁₂O₄₈.27H₂O, zeolite A ( Linde type A sodium form, NaA) which is used in laundry detergents.

Na₁₆Al₁₆Si₃₂O₉₆.16H₂O, Analcime, IUPAC code ANA.

Na₁₂Al₁₂Si₁₂O₄₈·q H2O Losod
Na₃₈₄Al₃₈₄Si₃₈₄O₁₅₃₆.518H₂O, Linde type N