Sodium iodide
Encyclopedia : S : SO : SOD : Sodium iodide
| Sodium iodide | |
|---|---|
| |
| General | |
| Molecular formula | NaI |
| Molar mass | 149.89 g/mol |
| Appearance | White solid. |
| CAS number | |
| Properties | |
| Density and phase | 3.67 g/cm3, solid |
| Solubility in water | 184 g/100 ml (25°C) |
| Melting point | 660°C |
| Boiling point | 1304°C |
| Structure | |
| Coordination geometry | Octahedral |
| Crystal structure | Halite |
| Hazards | |
| MSDS | External MSDS |
| EU classification | Irritant (I). |
| R-phrases | R36, R38, R42, R43, R61 |
| S-phrases | S26, S36, S37, S39 |
| NFPA 704 | N/A |
| NFPA 704 | |
| Flash point | Non-flammable. |
| RTECS number | WB6475000 |
| Supplementary data page | |
| Structure and properties | n, εr, etc. |
| Thermodynamic data | Phase behaviour Solid, liquid, gas |
| Spectral data | UV, IR, NMR, MS |
| Related compounds | |
| Other anions | Sodium fluoride Sodium chloride Sodium bromide |
| Other cations | Lithium iodide Potassium iodide |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) [Chemical infoboxInfobox disclaimer and references] | |
Sodium iodide is a white, crystalline salt with chemical formula NaI used in radiation dectection, treatment of iodine deficiency, and as a catalyst in the Finkelstein reaction.
| Solubility of NaI in various solvents (g NaI / 100g of solvent at 25°C) | |
|---|---|
| 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 |
| Reference: Burgess, J. Metal Ions in Solution (Ellis Horwood, New York, 1978) ISBN 0853120277 | |
Uses
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.
- R- + → R- +
Sodium iodide crystals doped with thallium, NaI(Tl), when subjected to ionising radiation, emit photons (scintillate) and are used in scintillation detectors, traditionally in nuclear medicine, geophysics, nuclear physics, environmental measurements, etc. NaI(Tl) is the most widely used scintillation material and has the highest light output. The crystals are usually coupled with a photomultiplier tube, in a hermetically sealed assembly, as sodium iodide is hygroscopic. Fine tuning of some parameters (radiation hardness, afterglow, transparency) can be achieved by varying the conditions of the crystal growth. Crystals with 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.
External links
- [International Chemical Safety Card 1009].
- [External MSDS Data Sheet].
- [Sodium Iodide's use in medicine].
- For a full list of external links to MSDSs, spectroscopic data, commercial chemicals suppliers etc. for this compound, see [Chemical sources].
From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.