Ammonium iodide

Ammonium iodide
Identifiers
CAS Number	12027-06-4 ;
3D model (JSmol)	Interactive image;
ChemSpider	23785 ;
ECHA InfoCard	100.031.548
PubChem CID	25487;
UNII	OZ8F027LDH ;
CompTox Dashboard (EPA)	DTXSID60894063 ;
	InChI InChI=1S/HI.H3N/h1H;1H3 Key: UKFWSNCTAHXBQN-UHFFFAOYSA-N ; InChI=1/HI.H3N/h1H;1H3 Key: UKFWSNCTAHXBQN-UHFFFAOYAU;
	SMILES [I-].[NH4+];
Properties
Chemical formula	NH4I
Molar mass	144.94 g/mol
Appearance	White crystalline powder
Density	2.51 g/cm3
Melting point	551 °C (1,024 °F; 824 K) (sublimes)
Boiling point	235 °C (455 °F; 508 K) (in vacuum)
Solubility in water	155 g/100 mL (0 °C) ; 172 g/100 mL (20 °C) ; 250 g/100 mL (100 °C)
Magnetic susceptibility (χ)	-66.0·10−6 cm3/mol
Hazards
NFPA 704 (fire diamond)	0 2 0
Flash point	Non-flammable
Related compounds
Other anions	Ammonium fluoride; Ammonium chloride; Ammonium bromide
Other cations	Sodium iodide; Potassium iodide; Phosphonium iodide
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Ammonium iodide is the chemical compound NH₄I. It is used in photographic chemicals and some medications.^[1] It can be prepared by the action of hydroiodic acid on ammonia. It is easily soluble in water, from which it crystallizes in cubes. It is also soluble in ethanol. It gradually turns yellow on standing in moist air, owing to decomposition with liberation of iodine.^[1]

Preparation

Ammonium iodide can be made in lab by reacting ammonia or ammonium hydroxide with hydroiodic acid or hydrogen iodide gas:

NH₃ + HI → NH₄I

NH₄OH + HI → NH₄I + H₂O

It is also formed by the decomposition of ammoniated triiodoamine (an explosive).

References

^ ^a ^b Holleman, A. F.; Wiberg, E. Inorganic Chemistry Academic Press: San Diego, 2001. ISBN 0-12-352651-5.

[Holleman-1] Holleman, A. F.; Wiberg, E. Inorganic Chemistry Academic Press: San Diego, 2001. ISBN 0-12-352651-5.

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