Ammonium chloride
Overview
 
Ammonium chloride NH4
Ammonium
The ammonium cation is a positively charged polyatomic cation with the chemical formula NH. It is formed by the protonation of ammonia...

Cl
Chloride
The chloride ion is formed when the element chlorine, a halogen, picks up one electron to form an anion Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. The chloride ion, and its salts such as sodium chloride, are very soluble in water...

 is an inorganic compound
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...

 with the formula NH4Cl. It is a white crystalline salt that is highly soluble in water. Solutions of ammonium chloride are mildly acidic. Sal ammoniac
Sal ammoniac
Sal ammoniac is a rare mineral composed of ammonium chloride, NH4Cl. It forms colorless to white to yellow-brown crystals in the isometric-hexoctahedral class. It has very poor cleavage and a brittle to conchoidal fracture. It is quite soft, with a Mohs hardness of 1.5 to 2, and has a low specific...

 is a name of natural, mineralogical form of ammonium chloride. The mineral is especially common on burning coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

 dumps (formed by condensation of coal-derived gases), but also on some volcanoes. It is the product from the reaction of hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....

 and ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

.
It is a by-product of the Solvay process
Solvay process
The Solvay process, also referred to as the ammonia-soda process, is the major industrial process for the production of soda ash . The ammonia-soda process was developed into its modern form by Ernest Solvay during the 1860s...

 used to produce sodium carbonate
Sodium carbonate
Sodium carbonate , Na2CO3 is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate is domestically well-known for its everyday use as a water softener. It can be extracted from the...

.

Ammonium chloride is prepared commercially by combining ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

 (NH3) with either hydrogen chloride
Hydrogen chloride
The compound hydrogen chloride has the formula HCl. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric humidity. Hydrogen chloride gas and hydrochloric acid are important in technology and industry...

 or hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....

:
NH3 + HCl → NH4Cl


Ammonium chloride occurs naturally in volcanic
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 regions, forming on volcanic rocks near fume-releasing vents (fumarole
Fumarole
A fumarole is an opening in a planet's crust, often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide. The steam is created when superheated water turns to steam as its pressure drops when it emerges from...

s).
Encyclopedia
Ammonium chloride NH4
Ammonium
The ammonium cation is a positively charged polyatomic cation with the chemical formula NH. It is formed by the protonation of ammonia...

Cl
Chloride
The chloride ion is formed when the element chlorine, a halogen, picks up one electron to form an anion Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. The chloride ion, and its salts such as sodium chloride, are very soluble in water...

 is an inorganic compound
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...

 with the formula NH4Cl. It is a white crystalline salt that is highly soluble in water. Solutions of ammonium chloride are mildly acidic. Sal ammoniac
Sal ammoniac
Sal ammoniac is a rare mineral composed of ammonium chloride, NH4Cl. It forms colorless to white to yellow-brown crystals in the isometric-hexoctahedral class. It has very poor cleavage and a brittle to conchoidal fracture. It is quite soft, with a Mohs hardness of 1.5 to 2, and has a low specific...

 is a name of natural, mineralogical form of ammonium chloride. The mineral is especially common on burning coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

 dumps (formed by condensation of coal-derived gases), but also on some volcanoes. It is the product from the reaction of hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....

 and ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

.

Sources

It is a by-product of the Solvay process
Solvay process
The Solvay process, also referred to as the ammonia-soda process, is the major industrial process for the production of soda ash . The ammonia-soda process was developed into its modern form by Ernest Solvay during the 1860s...

 used to produce sodium carbonate
Sodium carbonate
Sodium carbonate , Na2CO3 is a sodium salt of carbonic acid. It most commonly occurs as a crystalline heptahydrate, which readily effloresces to form a white powder, the monohydrate. Sodium carbonate is domestically well-known for its everyday use as a water softener. It can be extracted from the...

.

Ammonium chloride is prepared commercially by combining ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

 (NH3) with either hydrogen chloride
Hydrogen chloride
The compound hydrogen chloride has the formula HCl. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric humidity. Hydrogen chloride gas and hydrochloric acid are important in technology and industry...

 or hydrochloric acid
Hydrochloric acid
Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....

:
NH3 + HCl → NH4Cl


Ammonium chloride occurs naturally in volcanic
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 regions, forming on volcanic rocks near fume-releasing vents (fumarole
Fumarole
A fumarole is an opening in a planet's crust, often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide. The steam is created when superheated water turns to steam as its pressure drops when it emerges from...

s). The crystals deposit directly from the gaseous state, and tend to be short-lived, as they dissolve easily in water.

Giant squid
Giant squid
The giant squid is a deep-ocean dwelling squid in the family Architeuthidae, represented by as many as eight species...

 and some other large squid species maintain neutral buoyancy in seawater through an ammonium chloride solution which flows throughout their body and is lighter than seawater. This differs from the method of flotation used by fish, which involves a gas-filled swim bladder. The solution tastes somewhat like salmiakki
Salmiakki
Salty liquorice, also known as salmiak or salmiakki is a variety of liquorice flavoured with ammonium chloride, common in Netherlands, Nordic Countries, Baltic States and Northern Germany. Ammonium chloride gives salty liquorice an astringent, salty taste , which has been described as...

 and makes giant squid unattractive for general human consumption.

Reactions

Ammonium chloride sublimes easily through decomposition
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...

 into ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

 and hydrogen chloride
Hydrogen chloride
The compound hydrogen chloride has the formula HCl. At room temperature, it is a colorless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric humidity. Hydrogen chloride gas and hydrochloric acid are important in technology and industry...

 gas.
NH4Cl → NH3 + HCl


Ammonium chloride reacts with strong base, e.g. sodium hydroxide, to release ammonia gas:
NH4Cl + NaOH → NH3 + NaCl + H2O

Similarly, ammonium chloride also reacts with alkali metal carbonates at elevated temperatures, giving ammonia and alkali metal chloride:
2 NH4Cl + Na2CO3 → 2 NaCl + CO2 + H2O + 2 NH3


A 5% by weight solution of ammonium chloride in water has a pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...

 in the range 4.6 to 6.0.

Applications

Ammonium chloride is used to produce low temperatures in cooling bath
Cooling bath
A cooling bath is a mixture used in a laboratory when low temperatures are needed, for example to conduct low-temperature chemical reactions , to collect highly volatile liquids from distillation, or in cold traps...

s. For example, the zero point of the Fahrenheit temperature scale is determined by placing the thermometer in a mixture of ice, water, and ammonium chloride. Ammonium chloride solutions with ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

 are used as buffer solution
Buffer solution
A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base or a weak base and its conjugate acid. It has the property that the pH of the solution changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a...

s.

Biology and agriculture

In biological applications ammonium chloride serves as a nitrogen source and is used in fertilizers, as a feed supplement for cattle and as an ingredient in nutritive media for yeasts and many microorganisms.

Pyrotechnics

Ammonium chloride is an ingredient in fireworks and safety and contact explosives.

Textile and leather

Ammonium chloride is used in the textile and leather industry in dyeing, tanning textile printing and to luster cotton.

Metalwork

Ammonium chloride is used as a flux
Flux (metallurgy)
In metallurgy, a flux , is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time...

 in preparing metals to be tin coated, galvanized or soldered. It works as a flux by cleaning the surface of workpieces by reacting with the metal oxides at the surface to form a volatile metal chloride. For this purpose, it is sold in blocks at hardware stores for use in cleaning the tip of a soldering iron and can also be included in solder as flux.

Medicine

Ammonium chloride is used as an expectorant in cough medicine. Its expectorant action is caused by irritative action on the bronchial mucosa. This causes the production of excess respiratory tract fluid which presumably is easier to cough up. Ammonium salts are an irritant to the gastric mucosa and may induce nausea and vomiting.

Ammonium chloride is used as a systemic acidifying agent in treatment of severe metabolic alkalosis
Alkalosis
Alkalosis refers to a condition reducing hydrogen ion concentration of arterial blood plasma . Generally, alkalosis is said to occur when pH of the blood exceeds 7.45. The opposite condition is acidosis .-Causes:...

, in oral acid loading test to diagnose distal renal tubular acidosis, to maintain the urine at an acid pH in the treatment of some urinary-tract disorders.

Food

In several countries, ammonium chloride is known as sal ammoniac and used as food additive
Food additive
Food additives are substances added to food to preserve flavor or enhance its taste and appearance.Some additives have been used for centuries; for example, preserving food by pickling , salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines...

. The E number
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...

 for ammonium chloride used as a food additive is E510.

Ammonium chloride is used to spice up dark sweets called salty liquorice, in baking to give cookies a very crisp texture, and in the flavouring Salmiakki Koskenkorva
Salmiakki Koskenkorva
Salmiakki Koskenkorva, is a pre-mixed liqueur which caused a minor revolution in drinking culture in Finland during the 1990s. Canonically salmiakkikossu consists of Koskenkorva Viina vodka and ground up Turkish Pepper brand salty liquorice...

 for vodkas. In sub-continent (Indo-Pak), its used in making daily snacks like samosa and jalebi for crispiness.

Other applications

Ammonium chloride is used in a ~5% aqueous solution to work on oil wells with clay swelling problems.
It is also used as electrolyte in Zinc–carbon batteries.
Other uses include in hair shampoo, in the glue that bonds plywood, in cleaning products like lysol. In hair shampoo, it is used as a thickening agent in ammonium-based surfactant systems, such as ammonium lauryl sulfate
Ammonium lauryl sulfate
Ammonium lauryl sulfate is the common name for ammonium dodecyl sulfate . The dodecyl signifies the presence of a 12-member carbon chain in the molecular backbone which allows the molecule to bond with non-polar portions of molecules while the highly polar sulfate head allows the molecule to bond...

.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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