Hydrogen iodide
- Hydrogen iodide
- Hydrogen iodide
- Hydrogen iodide
- Iodan
A colorless, pungent gas
Gaseous
5.79 kg · m 3 (0 ° C)
-51 ° C
-35.4 ° C
0.73 MPa ( 20 ° C)
-10 (25 ° C)
425 g · l-1 (at 20 ° C ) in water
0.448 (1) D (1.49 · 10-30 C · m)
Risk
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Iodide ( Molecular Formula HI), also known as hydrogen iodide or hydrogen iodide, is a colorless, pungent, poisonous gas that is very readily soluble in water to form the strong hydroiodic acid. The bond length between the iodine and hydrogen atom is 160.9 pm.
History
The educational and decomposition reaction:
1894 was examined by the physical chemist Max Bodenstein in detail and with high precision. She was advised late 19th century to the attention of researchers because it enabled an observation of molecular equilibrium reactions. In addition to the hydrogen-oxygen reaction and formation of sulfur trioxide the Iodwasserstoffreaktion formed an experimental basis for a theory of the kinetics of gas reactions.
Production and representation
Industrial production is performed by the catalytic reaction of the gaseous element for a heated to 500 ° C, platinum sponge catalyst:
Chance and the reaction of iodine with hydrazine is used:
In addition, water from phosphorus triiodide iodide is capable of releasing:
This reaction is, however, unsuitable to drive really dry hydrogen iodide.
As a laboratory synthesis of hydrogen iodide itself offers the following opportunity:
Furthermore, it offers itself in the laboratory, hydrogen iodide from conc. Hydroiodic acid to obtain, although this does not constitute a representation in the strict sense.
Properties
Hydrogen iodide is one of the strongest known acids with a pKa value of -10. The absence of air it is stable. An air enters oxidation to iodine:
Oxidizing agents such as bromine and chlorine oxidize iodide to form the corresponding hydrogen halide to elemental iodine. When heated, hydrogen iodide splits into the elements hydrogen and iodine to ( reverse reaction of the formation reaction ).
Use
Hydrogen iodide is used for the preparation of iodides, organic iodine compounds, and as a catalyst. The analysis by chemical degradation, he played a significant role as a reducing agent.