Ammonium thiosulfate

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  Structural formula of Ammonium thiosulfate
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  3D van der Waals model of Ammonium thiosulfate
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  Image of Lytta vesicatoria, commonly known as the Spanish fly

Ammonium Thiosulfate

Ammonium thiosulfate is an inorganic compound with the formula (NH_)_S_O_. It is a white crystalline solid that is highly soluble in water. Ammonium thiosulfate is commonly used in various industrial and agricultural applications.

Chemical Properties

Ammonium thiosulfate is composed of ammonium ions (NH__) and thiosulfate ions (S_O___). The thiosulfate ion is a derivative of the sulfate ion (SO___) where one oxygen atom is replaced by a sulfur atom. This gives the thiosulfate ion unique chemical properties, including its ability to act as a reducing agent.

The compound is stable under normal conditions but decomposes upon heating, releasing ammonia and sulfur dioxide gases. In aqueous solution, ammonium thiosulfate can undergo oxidation to form sulfate and tetrathionate ions.

Uses

Photography

Ammonium thiosulfate is used in the photography industry as a fixer to dissolve unreacted silver halides from photographic emulsions. This process stabilizes the image and makes it insensitive to further exposure to light.

Agriculture

In agriculture, ammonium thiosulfate is used as a fertilizer. It provides a source of nitrogen and sulfur, both of which are essential nutrients for plant growth. The compound is often applied to the soil in liquid form, where it is absorbed by plant roots.

Mining

Ammonium thiosulfate is also used in the mining industry for the leaching of precious metals such as gold and silver. It serves as an alternative to cyanide in the extraction process, offering a less toxic method for recovering these metals from ores.

Safety and Handling

Ammonium thiosulfate should be handled with care, as it can decompose to release ammonia and sulfur dioxide, both of which are irritating to the respiratory system. Proper storage and handling procedures should be followed to minimize exposure and prevent accidental release.

Related Pages

• Thiosulfate
• Ammonium
• Fertilizer
• Photography
• Mining