Lead (II) iodide
Crystal structure | ||||||||||||||||
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__ Pb 2+ __ I - | ||||||||||||||||
Crystal system |
trigonal |
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Space group |
P 3 m 1 (No. 164) |
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General | ||||||||||||||||
Surname | Lead (II) iodide | |||||||||||||||
other names |
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Ratio formula | PbI 2 | |||||||||||||||
Brief description |
yellow, odorless solid |
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External identifiers / databases | ||||||||||||||||
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properties | ||||||||||||||||
Molar mass | 461.05 g mol −1 | |||||||||||||||
Physical state |
firmly |
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density |
6.16 g cm −3 |
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Melting point |
402 ° C |
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boiling point |
954 ° C |
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solubility |
0.756 g l −1 (20 ° C) |
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safety instructions | ||||||||||||||||
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . |
Lead (II) iodide is a toxic chemical compound made up of the elements lead and iodine .
Extraction and presentation
Lead (II) iodide is obtained through a precipitation reaction of lead (II) nitrate or lead (II) acetate with potassium iodide or sodium iodide .
In this way it can also serve as a detection reaction for lead.
properties
Lead (II) iodide is a yellowish to orange-colored solid that is sparingly soluble in water and melts at 402 ° C.
Under normal conditions it has a trigonal crystal structure with the space group P 3 m 1 (space group no.164) . At 305 ° C there is a phase transition to another modification. At least three high pressure modifications are also known.
use
In its crystalline form it is used as a detector material for high - energy photons such as X - rays and gamma rays . In the 19th century it was rarely used by artists as a yellow dye ( iodine yellow ), but was soon replaced by other dyes due to its toxicity and instability to light. Lead (II) iodide is used for photographic emulsions with thiols , brake linings containing asbestos , batteries with iodine , mercury vapor lamps , thermoelectric materials, electrosensitive recording materials and as a filter for infrared astronomy .
Individual evidence
- ↑ a b c d e f data sheet lead (II) iodide from AlfaAesar, accessed on January 23, 2010 ( PDF )(JavaScript required) . .
- ↑ NIST data review 1980
- ↑ a b Entry on lead (II) iodide in the GESTIS substance database of the IFA , accessed on July 23, 2016(JavaScript required) .
- ↑ Not explicitly listed in Regulation (EC) No. 1272/2008 (CLP) , but with the specified labeling it falls under the group entry lead compounds with the exception of those specified elsewhere in this Annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA) , accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
- ↑ John Moore, Conrad Stanitski: Chemistry: The Molecular Science . Cengage Learning, 2014, ISBN 978-1-285-19904-7 , pp. 105 ( limited preview in Google Book search).
- ↑ John K. Gilbert, David Treagust: Multiple Representations in Chemical Education . Springer Science & Business Media, 2009, ISBN 978-1-4020-8872-8 , pp. 161 ( limited preview in Google Book search).
- ↑ Evgeniĭ I︠U︡rʹevich Tonkov: High Pressure Phase Transformations A Handbook . CRC Press, 1992, ISBN 978-2-88124-759-0 , pp. 494 ( limited preview in Google Book search).
- ^ Safa Kasap, Peter Capper: Springer Handbook of Electronic and Photonic Materials . Springer Science & Business Media, 2006, ISBN 978-0-387-29185-7 , pp. 1129 ( limited preview in Google Book search).
- ^ Nicholas Eastaugh, Valentine Walsh, Tracey Chaplin, Ruth Siddall: Pigment Compendium: A Dictionary of Historical Pigments . Routledge, 2007, ISBN 978-1-136-37386-2 , pp. 228 ( limited preview in Google Book search).
- ↑ PJ Gellings, HJ Bouwmeester: Handbook of Solid State Electrochemistry . CRC Press, 1997, ISBN 978-1-4200-4930-5 , pp. 387 ( limited preview in Google Book search).
- ↑ Willy J. Masschelein, Rip G. Rice: Ultraviolet Light in Water and Wastewater Sanitation . CRC Press, 2002, ISBN 978-1-4200-3217-8 , pp. 34 ( limited preview in Google Book search).
- ↑ entry to LEAD IODIDE in the Hazardous Substances Data Bank , accessed on July 27, 2015.