Difference between revisions of "Ammonium sulfide"

Revision as of 19:07, 2 July 2017

Ammonium sulfide is an unstable ammonium salt with the formula (NH₄)₂S. It is a yellowish solid, stable below -18 °C.

As the hydrosulfide ion cannot be deprotonated to an appreciable amount by ammonia (pKa = 15), ammonium sulfide solutions also contain free ammonia and ammonium hydrosulfide (NH₄)SH.

Properties

Chemical

Ammonium sulfide will tarnish silver, by forming a layer of silver sulfide on its surface.

Physical

Ammonium sulfide is a yellow-ish solid compound at low temperatures, but unstable above -18 °C, with a strong unpleasant smell of rotten eggs. It is very soluble in water and ammonia, as well as alcohols.

Availability

Ammonium sulfide can be encountered as solution in "stink bombs".

Preparation

Can be made by bubbling ammonia through an aqueous solution of hydrogen sulfide. For higher purity, hydrogen sulfide is bubbled through anhydrous ammonia.

This procedure is very dangerous and should ONLY be performed in well ventilated areas, preferably in some place far away from civilization.

Projects

Ammonium sulfide can be a good source of concentrated hydrogen sulfide for many reactions, however, due to its instability it's recommended to perform experimentation only in well ventilated places and proper protection must be worn at all times.

• Make lead sulfide
• Stink bomb
• Selective reducing agent for some alkaloids

Handling

Safety

Ammonium sulfide releases hydrogen sulfide upon decomposition, which is very toxic. Proper protection must be worn all the time when handling the compound.

Storage

Storage of ammonium sulfide presents great difficulties, as even the slightest leak will create a foul smelling environment. Ampouling the compound is generally the best method.

Disposal

Hydrogen peroxide will oxidize ammonium sulfide to ammonium sulfate, which is safe to handle. Bubbling hot sulfur dioxide (70 °C) through the solution will give the same result.

It is recommended to avoid using bleach, as it may yield chloramines.

References

Relevant Sciencemadness threads

• Ammonium Sulfate to Ammonium Sulfide