Sodium iodide
From Sciencemadness Wiki
| Names | |
|---|---|
| IUPAC name
Sodium iodide
| |
| Other names
Sodium monoiodide
| |
| Properties | |
| NaI | |
| Molar mass | 149.89 g/mol |
| Appearance | White solid |
| Odor | Odorless |
| Density | 3.67 g/cm3 |
| Melting point | 661 °C (1,222 °F; 934 K) |
| Boiling point | 1,304 °C (2,379 °F; 1,577 K) |
| 158.7 g/100 ml (0 °C) 184.2 g/100 ml (25 °C) 227.8 g/100 ml (50 °C) 294 g/100 ml (70 °C) 302 g/100 ml (100 °C) | |
| Solubility | Reacts with sulfuric acid Soluble in acetone, acetonitrile, ethanol, formamide, formic acid, isopropanol, methanol Slightly soluble in dimethylformamide, liq. sulfur dioxide Insoluble in halocarbons, hydrocarbons |
| Solubility in acetamide | 32.3 g/100 g (41.5 °C) |
| Solubility in acetone | 50.4425 g/100 g (25 °C) |
| Solubility in acetonitrile | 24.9 g/100 g (25 °C) |
| Solubility in ammonia | 162 g/100 g (25 °C) |
| Solubility in dichloromethane | 0.009 g/100 g (25 °C) |
| Vapor pressure | ~0 mmHg |
| Thermochemistry | |
| Std molar
entropy (S |
91 J·mol−1·K−1 |
| Std enthalpy of
formation (ΔfH |
−288 kJ·mol−1 |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | Non-flammable |
| Lethal dose or concentration (LD, LC): | |
| LD50 (Median dose)
|
4.340 mg/kg (rat, oral) |
| Related compounds | |
| Related compounds
|
Potassium iodide |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Sodium iodide (NaI) is a chemical compound, a salt formed from sodium and iodine.
Contents
Properties
Chemical
Addition of a strong acid, like sulfuric acid will form hydroiodic acid, which decomposes to liberate elemental iodine.
- 2 NaI + H2SO4 → Na2SO4 + 2 HI
- 2 HI → H2 + I2
Physical
Sodium iodide is a colorless odorless solid, soluble in water.
Availability
Sodium iodide is sold by chemical suppliers.
Preparation
Can be made by neutralizing hydroiodic acid with sodium hydroxide/carbonate/bicarbonate:
- NaOH + HI → NaI + H2O
- Na2CO3 + 2 HI → 2 NaI + H2O + CO2
- NaHCO3 + HI → NaI + H2O + CO2
Another route is addition of iodine to sodium thiosulfate.
- 2 Na2S2O3 + I2 → 2 NaI + Na2S4O6
Projects
- Make hydrogen iodide and hydroiodic acid
- Make elemental iodine
- Finkelstein reaction
Handling
Safety
Sodium iodide has low toxicity.
Storage
Sodium iodide should be kept in closed bottles, plastic or glass.
Disposal
Sodium iodide wastes should be diluted with water and can be poured down the drain. It's recommended to try and recycle the iodine though.
