Bismuth (III) iodide

Crystal structure
__ Bi 3+      __ I -
General
Surname	Bismuth (III) iodide
other names	Bismuth triiodide
Ratio formula	BiI 3
Brief description	dark gray powder with a sour odor
External identifiers / databases
CAS number 7787-64-6 EC number 232-127-4 ECHA InfoCard 100.029.207 PubChem 24860889 ChemSpider 21172753 Wikidata Q425085
properties
Molar mass	589.69 g mol −1
Physical state	firmly
density	5.78 g cm −3
Melting point	408 ° C
boiling point	500 ° C (decomposition)
solubility	almost insoluble in water easily soluble in ethanol (500 g / l) easily soluble in liquid ammonia slightly soluble in benzene and toluene
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 314 P: 280-305 + 351 + 338-310
Thermodynamic properties
ΔH f 0	−150 kJ mol −1
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Bismuth (III) iodide is a salt of bismuth with hydriodic acid . It has the ratio formula BiI ₃ . Bismuth is in the +3 oxidation state.

presentation

Bismuth (III) iodide can be synthesized directly from the elements . For this purpose, finely divided bismuth and iodine are heated together.

${\displaystyle {\ce {2Bi + 3I2 -> 2BiI3}}}$

It can also be precipitated from a solution of bismuth (III) chloride in hydrochloric acid with concentrated hydriodic acid .

${\displaystyle {\ce {BiCl3 + 3HI -> BiI3 + 3HCl}}}$

properties

It is a gray to black solid that melts at 408 ° C. Sublimated or recrystallized, it forms black, fat-shining, graphite-like flakes. Bismuth (III) iodide crystallizes in the trigonal crystal system .

use

Since bismuth (III) iodide is insoluble in water, it can be used to detect bismuth. When a water-soluble iodide salt (for example potassium iodide ) is added, solutions containing Bi (III) precipitate gray bismuth (III) iodide and thus indicate the presence of bismuth. Upon further addition of the iodide salt, the precipitate dissolves again with the formation of an orange tetraiodobismuthate complex ([BiI ₄ ] ^- ).

It is currently (2017) being considered whether one can slow down global warming by introducing bismuth (III) iodide into the atmosphere (so-called geoengineering ) . David Mitchell from the University of Nevada suggests using 160 tons annually (cost: approx. 6 million US dollars) for this.

Individual evidence

1. ↑ ^{a b c} data sheet bismuth (III) iodide from AlfaAesar, accessed on January 7, 2010 ( PDF )(JavaScript required) .
2. ↑ ^{a b} George W. Watt et al .: Bismuth (III) iodide . In: JC Bailar, Jr. (Ed.): Inorganic Syntheses . tape 4 . McGraw-Hill, Inc., 1953, pp. 114-116 (English).
3. ↑ ^{a b c d} data sheet bismuth (III) iodide from Sigma-Aldrich , accessed on March 13, 2011 ( PDF ).
4. ↑ ^{a b} Georg Brauer (Ed.), With the collaboration of Marianne Baudler u a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 600.
5. ^ AF Holleman , N. Wiberg : Inorganische Chemie . 103rd edition. Volume 1: Basics and main group elements. Walter de Gruyter, Berlin / Boston 2016, ISBN 978-3-11-049585-0 , p. 952 (reading sample: Part A - Basics of the chemistry of hydrogen. Google book search ).
6. ^ H. Erdmann, FL Dunlap: Handbook of Basic Tables for Chemical Analysis , John Wiley & Sons New York, p. 76.
7. ↑ ^{a b} Jander, Blasius, Strähle: Introduction to the inorganic chemical internship . 14th edition. Hirzel, Stuttgart 1995, ISBN 978-3-7776-0672-9 .
8. ↑ James Temple: The Growing Case for Geoengineering. In: MIT Technology Review . April 18, 2017, accessed June 28, 2017.