Ammonium sulfide

Not to be confused with ammonium sulfite.

Ammonium sulfide

Names
IUPAC name Ammonium sulfide
Other names Diammonium sulfide Diazanium sulfide
Identifiers
Jmol-3D images	Image
SMILES [S-2].[NH4+].[NH4+]
Properties
Chemical formula	(NH4)2S
Molar mass	68.154 g/mol
Appearance	Yellow crystals
Odor	Unpleasant, rotten eggs-like
Density	0.997 g/cm3
Melting point	Decomposes
Boiling point	Decomposes
Solubility in water	128.1 g/100 mL (at 20 °C)
Solubility	Reacts with acids, bases Soluble in liquid ammonia, ethanol, methanol
Hazards
Safety data sheet	FisherScientific
Flash point	32.22 °C
Related compounds
Related compounds	Hydrogen sulfide Ammonium sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

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 yellowish solid compound at low temperatures, but unstable above -18 °C, with a very strong and highly 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, dry 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.

As the compound readily realeases hydrogen sulfide, extreme safety must be employed when working with the compound. A property of H₂S is that is can temporarily deaden a person's sense of smell, a sickening effect that a few Sciencemadness members have had personal experiences with. If you are in an area with a strong smell of hydrogen sulfide, and then that strong smell suddenly disappears for no apparent reason, immediately leave the area! At the concentration where this occurs, the gas is potentially deadly, with a toxicity not very far from the infamous hydrogen cyanide, not to mention undetectable. Safety plans should be in order during any experiment which makes use of hydrogen sulfide, including a way to quickly leave the room/area.

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