Ammonium chloride
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| Ammonium chloride | |
|---|---|
| |
| General | |
| Systematic name | Ammonium chloride |
| Chemical formula | NH4Cl |
| Appearance | white crystalline powder |
| Physical | |
| Formula weight | 53.4913 |
| Melting point | 338°C (640F) sublimes |
| Boiling point | 520°C (968F) |
| Density | 1.527 |
| Crystal structure | Isometric |
| Solubility | 29.7g/100g water @ 0°C |
| Thermochemistry | |
| ΔfH0gas | kJ/mol |
| ΔfH0liquid | kJ/mol |
| ΔfH0solid | -314.55 kJ/mol |
| S0gas, 1 bar | J/mol·K |
| S0liquid, 1 bar | J/mol·K |
| S0solid | 94.85 J/mol·K |
| Safety | |
| Ingestion | Induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water.Seek medical help |
| Inhalation | Remove from exposure to fresh air. Seek medical help |
| Skin | Wash off with plenty of soap and water |
| Eyes | Flush eyes with plenty of clean water. Seek medical help. |
| NFPA 704 | |
| More info | [Hazardous Chemical Database] |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) [Chemical infoboxInfobox disclaimer and references] | |
Ammonium chloride or Sal Ammoniac (chemically ammonium chloride (NH4Cl); also nushadir salt, zalmiak, sal armagnac, sal armoniac, salmiakki, and salt armoniack) is, in its pure form, a clear white water-soluble crystalline salt with a biting taste.
In nature, the substance occurs in volcanic regions, forming on volcanic rocks near fume-releasing vents. The crystals deposit directly from the gaseous state, and tend to be short-lived, as they dissolve easily in water.
It is easy to produce artificially and is often created as a byproduct of other industries.
Uses
Historically it was considered one of the four alchemical "spirits". While the way that it dissociates into two corrosive materials (ammonia and hydrochloric acid) which attack metals convinced some eager alchemists that it might hold the key to converting one metal to another, Arabs used it as a source of ammonia:
- :2NH4Cl + 2CaO → CaCl2 + Ca(OH)2 + 2NH3
- : NaClO4 + NH4Cl → NH4ClO4 + NaCl
Other uses include a feed supplement for cattle, in hair shampoo, in textile printing, in the glue that bonds plywood, as an ingredient in nutritive media for yeast, in cleaning products, and as 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. It is the active ingredient in many antiperspirants, usually used in aerosol antiperspirants.
Ammonium chloride is used in snow treatment, namely on ski slopes at temperatures above 0 °C, to harden the snow and slow its melting. [link]
In several countries sal ammoniac is used to spice up liquorice-type dark candies (Finland's salmiakki is a popular example), and as a flavoring for vodkas.
In history
It was first synthesized by Arab alchemist Jabir ibn Hayyan circa 740 AD.A legend says sal ammoniac was named after it was observed in the Temple of Zeus-Ammon in Egypt; its name means "salt of Ammon". It was the white crystalline substance that remained on the ceiling and walls after camel dung was burnt. The modern name "ammonium" comes from sal ammoniac. The substance was known as nushadir salt (Arabic and Persian: نشادر) in Arabic-speaking countres and Persia, naosha (}; }) in China, nao sadar in India.
See also
External links
- For a full list of external links to MSDSs, spectroscopic data, commercial chemicals suppliers etc. for this compound, see [Chemical sources].
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