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Aluminium sulfate

 
Aluminium Sulfate

 
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Aluminium sulfate
 
 
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Aluminium sulfate, written as Al
Aluminium

Aluminium or aluminum is a silvery white and ductile member of the boron group of chemical elements. It has the symbol Al; its atomic number is 13....
2(S
Sulfur

Sulfur or sulphur is the chemical element that has the atomic number 16. It is denoted with the symbol S. It is an abundant Valence non-metal....
O4
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
)3 or Al
Aluminium

Aluminium or aluminum is a silvery white and ductile member of the boron group of chemical elements. It has the symbol Al; its atomic number is 13....
2O12
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
S
Sulfur

Sulfur or sulphur is the chemical element that has the atomic number 16. It is denoted with the symbol S. It is an abundant Valence non-metal....
3 Aluminium sulfate is an industrial chemical used as a flocculating agent
Flocculation

Flocculation is a process where a solute comes out of solution in the form of floc or flakes. The action differs from Precipitation in that the solute coming out of solution does so at a concentration generally below its solubility limit in the liquid....
 in the purification of drinking water and waste water treatment plants, and also in paper manufacturing.

Aluminium sulfate is sometimes incorrectly referred to as alum
Alum

Alum, refers to a specific chemical compound and a class of chemical compounds. The specific compound is the hydrated aluminum potassium sulfate with the chemical formula KAl2.12H2O....
 but alums are closely related compounds typified by KAl(SO4)2.12H2O.






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Encyclopedia


Aluminium sulfate, written as Al
Aluminium

Aluminium or aluminum is a silvery white and ductile member of the boron group of chemical elements. It has the symbol Al; its atomic number is 13....
2(S
Sulfur

Sulfur or sulphur is the chemical element that has the atomic number 16. It is denoted with the symbol S. It is an abundant Valence non-metal....
O4
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
)3 or Al
Aluminium

Aluminium or aluminum is a silvery white and ductile member of the boron group of chemical elements. It has the symbol Al; its atomic number is 13....
2O12
Oxygen

Oxygen no O2 produced; 2) O2 produced, but absorbed in oceans & seabed rock; 3) O2 starts to gas out of the oceans, but is absorbed by land surfaces and formation of ozone layer; 4-5) O2 sinks filled and the gas accumulates]]...
S
Sulfur

Sulfur or sulphur is the chemical element that has the atomic number 16. It is denoted with the symbol S. It is an abundant Valence non-metal....
3 Aluminium sulfate is an industrial chemical used as a flocculating agent
Flocculation

Flocculation is a process where a solute comes out of solution in the form of floc or flakes. The action differs from Precipitation in that the solute coming out of solution does so at a concentration generally below its solubility limit in the liquid....
 in the purification of drinking water and waste water treatment plants, and also in paper manufacturing.

Aluminium sulfate is sometimes incorrectly referred to as alum
Alum

Alum, refers to a specific chemical compound and a class of chemical compounds. The specific compound is the hydrated aluminum potassium sulfate with the chemical formula KAl2.12H2O....
 but alums are closely related compounds typified by KAl(SO4)2.12H2O. The anhydrous form occurs naturally as a rare mineral
Mineral

A mineral is a naturally occurring solid formed through Geology processes that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties....
 millosevichite
Millosevichite

Millosevichite is a rare mineral of the chemical formula written as Al23. Aluminium is often substituted by Iron. It forms white to yellowish cryptocrystalline, often porous, masses....
, found i.e. in volcanic environments and on burning coal-mining waste dumps. Aluminium sulfate is rarely, if ever, encountered as the anhydrous salt. It forms a number of different hydrate
Hydrate

Hydrate is a term used in inorganic chemistry and organic chemistry to indicate that a substance contains water. The chemical state of the water varies widely between hydrates, some of which were so labeled before their chemical structure was understood....
s, of which the hexadecahydrate Al2(SO4)3•16H2O and octadecahydrate Al2(SO4)3•18H2O are the most common. The heptadecahydrate, whose formula can be written as [Al(H2O)6]2(SO4)3•5H2O, occurs naturally as the mineral alunogen
Alunogen

Alunogen also called feather alum and hair salt is a colourless to white fibrous to needle-like aluminium sulfate mineral often found on the walls of mines and quarries as secondary mineral....
.

Preparation


Aluminium sulfate may be made by dissolving aluminium hydroxide
Aluminium hydroxide

Aluminium hydroxide, Al3, is the most stable form of aluminium in normal conditions. It is found in nature as the mineral gibbsite and its three, much more rare, polymorphs: bayerite, doyleite and nordstrandite....
, Al(OH)3, in sulfuric acid
Sulfuric acid

Sulfuric acid, hydrogen2sulfuroxygen4, is a strong mineral acid. It is soluble in water at all concentrations. Sulfuric acid has many applications, and is one of the top products of the chemical industry....
, H2SO4:

2 Al(OH)3 + 3 H2SO4 ? Al2(SO4)3·6H2O


Uses


Aluminium Sulfate is used in water purification
Water purification

This article discusses large scale, municipal water purification. For portable/emergency water purification, see Portable water purification.Water purification is the process of removing undesirable chemical and biological contaminants from raw water....
 and as a mordant
Mordant

A mordant is a substance used to set dyes on fabrics by forming an insoluble compound with the dye. It may be used for dyeing fabrics, or for intensifying stains in cell or tissue preparations....
 in dyeing and printing textiles. In water purification, it causes impurities to coagulate which are removed as the particulate settles to the bottom of the container or more easily filtered. This process is called coagulation
Coagulation

Coagulation is a complex process by which blood forms clots. It is an important part of hemostasis , wherein a damaged blood vessel wall is covered by a platelet and fibrin-containing clot to stop hemorrhage and begin repair of the damaged vessel....
 or flocculation
Flocculation

Flocculation is a process where a solute comes out of solution in the form of floc or flakes. The action differs from Precipitation in that the solute coming out of solution does so at a concentration generally below its solubility limit in the liquid....
.

When dissolved in a large amount of neutral or slightly-alkaline water, aluminium sulfate produces a gelatinous precipitate of aluminium hydroxide
Aluminium hydroxide

Aluminium hydroxide, Al3, is the most stable form of aluminium in normal conditions. It is found in nature as the mineral gibbsite and its three, much more rare, polymorphs: bayerite, doyleite and nordstrandite....
, Al(OH)3. In dyeing and printing cloth, the gelatinous precipitate helps the dye adhere to the clothing fibers by rendering the pigment insoluble.

Aluminium sulfate is sometimes used to reduce the pH
PH

pH is a measure of the Acid or Base of a solution. It is defined as the cologarithm of the Activity of dissolved hydrogen ions . Hydrogen ion activity coefficients cannot be measured experimentally, so they are based on theoretical calculations....
 of garden soil, as it hydrolyzes
Hydrolysis

Hydrolysis is a chemical reaction during which one or more water are split into hydrogen and hydroxide ions which may go on to participate in further reactions....
 to form the aluminium hydroxide precipitate and a dilute sulfuric acid
Sulfuric acid

Sulfuric acid, hydrogen2sulfuroxygen4, is a strong mineral acid. It is soluble in water at all concentrations. Sulfuric acid has many applications, and is one of the top products of the chemical industry....
 solution.

Aluminium sulfate is the active ingredient of some antiperspirants; however, beginning in 2005 the US Food and Drug Administration
Food and Drug Administration

The U.S. Food and Drug Administration is an Government agency of the United States Department of Health and Human Services and is responsible for regulating and supervising the safety of foods, dietary supplements, Medications, vaccines, Biopharmaceutical, blood transfusion, medical devices, Electromagnetic radiation-emitting devices, veteri...
 no longer recognized it as a wetness reducer.

Aluminium sulfate is usually found in baking powder
Baking powder

Baking powder is a dry chemical leavening agent used to increase the volume and lighten the texture of baked goods such as muffins, cakes, and cookies ....
, where there is controversy over its use due to concern regarding the safety of adding aluminum to the diet.

In construction industry it is used as waterproofing agent and accelerator in concrete
Concrete

Concrete is a construction material composed of cement as well as other cementitious materials such as fly ash and slag cement, construction aggregate , water , and Chemistry admixtures....
. Another use is a foaming agent in fire fighting foam.

It is also used in styptic pencils, and pain relief from stings and bites; it is the active ingredient in popular pain relief products such as Stingose.

It can also be very effective as a molluscicide
Molluscicide

Molluscicides, also known as snail baits and snail pellets, are pesticides against molluscs, which are usually used in agriculture or gardening to control slugs and snails that can damage crops by feeding on them....
, killing spanish slug
Spanish slug

The Spanish slug, more commonly known in English language-speaking countries under its Latin name, Arion lusitanicus, is a species of air-breathing land slug, a terrestrial animal pulmonate gastropod mollusk in the family Arionidae, the roundback slugs....
s.

See also


External links