Iodoform
| Names | |
|---|---|
| IUPAC name
Triiodomethane
| |
| Preferred IUPAC name
Triiodomethane | |
| Other names
Carbon triiodide
| |
| Properties | |
| CHI3 | |
| Molar mass | 393.73 g/mol |
| Appearance | Yellowish powder |
| Odor | Saffron-like "Hospital"-like |
| Density | 4.008 g/cm3 |
| Melting point | 119 °C (246 °F; 392 K) |
| Boiling point | 218 °C (424 °F; 491 K) |
| 0.1 g/L | |
| Solubility | Soluble in glacial acetic acid, benzene, carbon disulfide, chloroform Slightly soluble in glycerol, olive oil, petroleum ether |
| Solubility in diethyl ether | 136 g/L |
| Solubility in acetone | 120 g/L |
| Solubility in ethanol | 78 g/L |
| Thermochemistry | |
| Std enthalpy of
formation (ΔfH |
180.1–182.1 kJ·mol−1 |
| Hazards | |
| Safety data sheet | AcrosOrganics |
| Flash point | 204 °C |
| Lethal dose or concentration (LD, LC): | |
| LD50 (Median dose)
|
355 mg/kg (oral, rat) 1180 mg/kg (dermal, rat) 1.6 mmol/kg (s.c., mouse) |
| Related compounds | |
| Related compounds
|
Chloroform Bromoform |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Iodoform is a yellowish organoiodine compound with the formula CHI3.
Contents
Properties
Chemical
Iodoform reacts with silver nitrate to yield carbon monoxide.
- AgNO3 + CHI3 → AgI + CO + I2 + ½ N2 + O2 + ½ H2
Iodoform can be reduced with hydrogen iodide to diiodomethane:
- CHI3 + HI → CH2I2 + I2
Physical
Triiodomethane is a pale yellow, crystalline, volatile substance, with a very strong penetrating and distinctive odor, reminiscent of hospitals, due to its use as a desinfectant. It is practically insoluble in water, but soluble in organic solvents such as acetone, benzene, chloroform, diethyl ether.
Availability
Iodoform is sold in pharmacies, either as a powder or as ether solution. Vet shops also carry it.
Angel's bonnets naturally produce a small amount of iodoform, which gives their characteristic smell, but extracting it may not be practical.
Preparation
Iodoform can be prepared very easy via the haloform reaction, by reacting iodine, sodium hydroxide with a ketone, such as acetone. As iodoform is practically insoluble in water, the suspension is filtered and then air dried.
A less known route involves passing iodine vapors with steam over red hot coals. The resulting product is purified via distillation, though if the coal used impurities, many other side products will also be produced.[1]
Reacting chloroform with calcium iodide at 100 °C yields iodoform.[2]
Projects
- Antiseptic
- Make diiodomethane
Handling
Safety
Iodoform is irritant and should be handled with care. Most people find its strong odor obnoxious, so work must be done in well ventilated areas, and never indoors as the odor is quite persistent.
Since CHI3 is used as an antiseptic in medicine, proper protection like gloves and coat should be worn when handling the compound.
Storage
CHI3 must be kept in amber glass bottles, bottles with a PTFE seal are recommended to limit its escape, preferably away from light and if possible, air. Do not use plastic, as iodoform will will irreversible stain it, especially if in contact with air (elemental iodine is formed) and absolutely never in metal containers.
Disposal
Can be neutralized with a strong base. This gives sodium iodide which can be recycled, as it's a source of iodine.
References
- ↑ http://gallica.bnf.fr/ark:/12148/bpt6k6137757n/f2.image
- ↑ Spindler; Justus Liebigs Annalen der Chemie; vol. 231; (1885); p. 272
