What Is Sodium Iodide?
Sodium iodide, an odorless white crystalline powder or granules, is known for its chemical formula NaI and molecular weight of 149.89. With a melting point of 661°C, it’s highly soluble in water and ethanol.
Uses of Sodium Iodide
Employed in the synthesis of organoiodine compounds through the Finkelstein reaction, sodium iodide’s applications extend to scintillation radiation detection and addressing iodine deficiency. It’s crucial in medical treatments, scintillation detection, and as an animal feed nutrient.
1. Medical Care
Addressing iodine deficiency, sodium iodide is vital for preventing goiter and hypothyroidism. It acts as a thyroid-blocking agent during nuclear incidents to prevent radioactive iodine absorption.
2. Scintillation Detection
As a scintillator, sodium iodide detects gamma radiation through fluorescence, making it invaluable in gamma-ray detection.
3. Animal Nutrition
As an essential nutrient, sodium iodide is incorporated into livestock feed to support thyroid function and overall health.
Properties of Sodium Iodide
This white crystalline solid has a density of 3.67 g/cm³ and dissolves readily in water, offering a salty taste. Hygroscopic, it degrades upon exposure to air, necessitating sealed storage. Its high refractive index and fluorescence under radiation underscore its use in scintillators.
Structure of Sodium Iodide
The ionic compound exhibits a face-centered cubic crystal structure, with sodium cations surrounded by six iodide anions and vice versa, mirroring the structure of cesium iodide.
Other Information on Sodium Iodide
How Sodium Iodide Is Produced
Produced through direct, metathesis, and solid-state reactions, the predominant method involves reacting sodium hydroxide or sodium carbonate with iodine, yielding sodium iodide alongside water or carbon dioxide.
The chemical reactions: NaOH + HI → NaI + H2O
Na2CO3 + HI → NaI + H2O + CO2
Alternative production methods include electrolysis and the reaction of metallic sodium with iodine, though less commonly employed.