48 lines
1.8 KiB
Markdown
48 lines
1.8 KiB
Markdown
## Ammonium chloride
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**Formula**
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$NH4Cl$
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**Pyrotechnic use**
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Smoke colorant
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**Synonyms**
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Zalmiak
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**Description**
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Ammonium chloride is used in smoke compositions.
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When heated ammonium chloride decomposes to HCl and NH3, both gasses. These
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recombine in the air to give a smoke consisting of fine particles of ammonium
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chloride.
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**Sources**
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Ammonium chloride solution is easily prepared by neutralising ammonia
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solution with hydrochloric acid. It is advised to use a slight excess of
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ammonia. That is to make sure no remaining acid will be present in the ammonium
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chloride obtained on evaporation and crystallisation. Otherwise traces of the
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acid solution may be enclosed in the crystals, possibly leading to spontaneous
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ignition of mixtures made with it.
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**Hazards**
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Ammonium chloride based smoke is irritating to the eyes and lungs as
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it contains some remaining HCl and NH3. Ammonium chloride itself is not
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poisonous and is even used in some type of candy. But as with all fine powders
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a dust mask must be worn, and since ammonium chloride is irritating to the skin
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and damaging to the eyes, gloves and goggles are important. Acording to
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Shimizu, ammonium chloride forms an exception to the rule that ammonium
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compounds should not be mixed with chlorates. Due to the lower solubility of
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potassium chlorate (compared to ammonium chlorate) no ammonium chlorate should
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form. I personally would still use these mixtures with great caution (or avoid
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them) since it seems inevitable that small amounts of ammonium chlorate will
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still form. The lower solubility of potassium chlorate will make it the -main-
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product in a double decomposition reaction but not the -only- product. It is
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strongly advised not to mix with metal powders, specifically copper, because it
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will become extremely corrosive. Toxicity: Oral rat LD50 : 1650 mg/kg
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Investigated as a mutagen.
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