Iodine pentoxide
| Names | |
|---|---|
| IUPAC name
Iodine pentoxide
| |
| Preferred IUPAC name
Iodine pentoxide | |
| Systematic IUPAC name
Iodine pentoxide | |
| Other names
Diiodine pentoxide
Diiodopentoxide Iodic anhydride Iodine pentaoxide Iodine(V) oxide Iodopentoxide Iodyl iodate | |
| Properties | |
| I2O5 | |
| Molar mass | 333.81 g/mol |
| Appearance | White solid |
| Odor | Odorless (pure) Iodine (impure) |
| Density | 5.08 g/cm3 (20 °C) |
| Melting point | 350 °C (662 °F; 623 K) (decomposes) |
| Boiling point | Decomposes |
| 187 g/100 ml (hydrolysis) | |
| Solubility | Soluble in nitric acid Insoluble in acetonitrile, carbon disulfide, chloroform, diethyl ether, ethanol |
| Vapor pressure | ~0 mmHg |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | Non-flammable |
| Related compounds | |
| Related compounds
|
Dichlorine heptoxide Dibromine pentoxide |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Iodine pentoxide is the chemical compound with the formula I2O5. This iodine oxide is the anhydride of iodic acid, and the only stable oxide of iodine.
Contents
Properties
Chemical
Iodine pentoxide hydrolyzes in water to form iodic acid.[1]
- I2O5 + H2O → 2 HIO3
Iodine pentoxide easily oxidizes carbon monoxide to carbon dioxide at room temperature. Conc. sulfuric acid may be needed to activate the reaction.
- 5 CO + I2O5 → I2 + 5 CO2
This reaction, called Ditte's reaction, can be used to analyze the concentration of CO in a gaseous sample.
Iodine pentoxide will react with hydrogen sulfide, forming sulfur dioxide:
- 3 I2O5 + 5 H2S → 3 I2 + 5 SO2 + 5 H2O
Elemental sulfur will also oxidize to sulfur dioxide, though strong heat is required to initiate the reaction.
- 2 I2O5 + 5 S → 5 I2 + 2 SO2
A mixture of carbon and iodine pentoxide will ignite with a drop of conc. sulfuric acid is added to it.
Iodine pentoxide reacts violently with hydrazine at standard conditions, producing HI.[2]
Mixing iodine pentoxide with lithium borohydride is sufficient to ignite said mixture.
Iodine pentoxide will oxidize hydrogen chloride aka hydrochloric acid to chlorine, while forming tetrachloroiodic acid.
- I2O5 + 12 HCl → 2 HICl4 + 2 Cl2 + 5 H2O
I2O5 forms iodyl salts, [IO2+], with sulfur trioxide and bis(fluorosulfuryl)peroxide, but iodosyl salts, [IO+], with concentrated sulfuric acid.
Physical
Iodine pentoxide is a white dense solid, that readily hydrolyzes in water. The pure compound is odorless, but exposure to impurities will release minute amounts of elemental iodine, giving the sample a faint iodine-like odor.
Availability
Iodine pentoxide can be bought from chemical suppliers.
Preparation
Iodine pentoxide is produced by dehydrating iodic acid at 200 °C in a stream of dry air:
- 2 HIO3 → I2O5 + H2O
Heating metaperiodic acid to around 150 °C gives iodine pentoxide (I2O5) rather than the expected anhydride diiodine heptoxide (I2O7), while releasing oxygen as byproduct.[3]
- 2 HIO4 → I2O5 + H2O + O2
Projects
- Detection of carbon monoxide
- Make Al-I2O5 thermite
Handling
Safety
Iodine pentoxide is a powerful oxidizer and may ignite combustible materials on contact.
Storage
In closed airtight bottles.
Disposal
Should be reduced with sodium thiosulfate or some other reducing agent.
References
- ↑ IODINE Its Properties and Technical Applications, CHILEAN IODINE EDUCATIONAL BUREAU, INC., 120 Broadway, New York 5, New York, 1951
- ↑ https://www.youtube.com/watch?v=3ad5TjGGX94
- ↑ https://www.bionity.com/en/encyclopedia/Periodic_acid.html
