Formula NH4I Melting point 551 °C Appearance White crystalline powder | Molar mass 144.94 g/mol Density 2.51 g/cm³ | |
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Ammonium iodide is the chemical compound NH4I. It is used in photographic chemicals and some medications. 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.
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 + H2OIt is also formed on decomposition of ammoniated nitrogentriiodide (an explosive).
References
Ammonium iodide Wikipedia(Text) CC BY-SA