| Sodium iodide | |
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| Identifiers | |
| CAS number | 7681-82-5 , 13517-06-1 (dihydrate) |
| PubChem | 5238 |
| ChemSpider | 5048 |
| UNII | F5WR8N145C |
| ChEBI | CHEBI:33167 |
| ChEMBL | CHEMBL1644695 |
| RTECS number | WB6475000 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | NaI |
| Molar mass | 149.89 g/mol |
| Appearance | white solid deliquescent |
| Density | 3.67 g/cm3 |
| Melting point |
661 °C, 934 K, 1222 °F |
| Boiling point |
1304 °C, 1577 K, 2379 °F |
| Solubility in water | 178.8 g/100 mL (20 °C) 184 g/100 mL (25 °C) 294 g/100 mL (70 °C) |
| Solubility | soluble in ethanol and acetone (39.9 g/100 mL) |
| Structure | |
| Coordination geometry |
Octahedral |
| Hazards | |
| MSDS | [1] |
| EU Index | Not listed |
| Main hazards | Irritant, can harm the unborn child |
| Flash point | Non-flammable |
| Related compounds | |
| Other anions | Sodium fluoride Sodium chloride Sodium bromide |
| Other cations | Lithium iodide Potassium iodide Rubidium iodide Caesium iodide |
| (verify) (what is: /?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Sodium iodide is a white, crystalline salt with chemical formula NaI used in radiation detection, treatment of iodine deficiency, and as a reactant in the Finkelstein reaction.
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Sodium iodide is commonly used to treat and prevent iodine deficiency.
Sodium iodide is used in polymerase chain reactions, and also (as an acetone solution) in the Finkelstein reaction, for conversion of an alkyl chloride into an alkyl iodide. This relies on the insolubility of sodium chloride in acetone to drive the reaction.
Sodium iodide activated with thallium, NaI(Tl), when subjected to ionizing radiation, emits photons (i.e., scintillate) and is used in scintillation detectors, traditionally in nuclear medicine, geophysics, nuclear physics, and environmental measurements. NaI(Tl) is the most widely used scintillation material and has the highest light yield of the commonly used scintillators. The crystals are usually coupled with a photomultiplier tube, in a hermetically sealed assembly, as sodium iodide is hygroscopic. Fine-tuning of some parameters (i.e., radiation hardness, afterglow, transparency) can be achieved by varying the conditions of the crystal growth. Crystals with a higher level of doping are used in X-ray detectors with high spectrometric quality. Sodium iodide can be used both as single crystals and as polycrystals for this purpose.
The radioactive iodide salt of sodium, Na131I, is used for the treatment of thyroid cancer and hyperthyroidism.[1]
| H2O | 184 |
| Liquid ammonia | 162 |
| Liquid sulfur dioxide | 15 |
| Methanol | 62.5 - 83.0 |
| Formic acid | 61.8 |
| Acetonitrile | 24.9 |
| Acetone | 28.0 |
| Formamide | 57 - 85 |
| Acetamide | 32.3 |
| Dimethylformamide | 3.7 - 6.4 |
| [2] | |