Lead (II) oxide

Crystal structure
__ Pb 2+      __ O 2−
General
Surname	Lead (II) oxide
other names	Black lead Lead monoxide Lithargite Massicotite
Ratio formula	PbO
Brief description	orthorhombic yellow or tetragonal red crystals
External identifiers / databases
CAS number 1317-36-8 EC number 215-267-0 ECHA InfoCard 100,013,880 PubChem 14827 ChemSpider 14141 Wikidata Q407879
properties
Molar mass	223.19 g mol −1
Physical state	firmly
density	9.53 g cm −3
Melting point	888 ° C
boiling point	1470 ° C
solubility	almost insoluble in water (17 mg l −1 )
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary danger H and P phrases H: 302 + 332-351-360Df-362-372-410 P: 201-260-263-280-301 + 312 + 330-308 + 313
Authorization procedure under REACH	of particular concern : toxic for reproduction ( CMR )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Lead (II) oxide is a compound of the chemical elements lead and oxygen with the ratio formula PbO. Other lead oxides besides lead (II) oxide are lead (II, IV) oxide and lead (IV) oxide .

Extraction and presentation

Lead (II) oxide can be made by passing a stream of air over molten lead:

${\displaystyle \mathrm {2\,Pb+O_{2}\rightarrow 2\,PbO} }$

This reaction is the basis of cupellation , in which lead (II) oxide is a by-product. It is also formed when roasting ores containing lead such as galena (lead luster):

${\displaystyle \mathrm {2\ PbS+3\ O_{2}\rightarrow 2\,PbO+2\ SO_{2}} }$

properties

Lead (II) oxide is a red solid with a tetragonal crystal structure and is known as a mineral under the name lithargite (formerly lithargyrum ). At 488 ° C this modification changes into a yellow, orthorhombic modification known as a mineral under the name massicotite . Because of the slow conversion rate at low temperatures, the yellow modification occurs as a metastable compound.

Names and uses

This also (depending on modification) as Massicotit , litharge (from Middle High German blīglete shortly also glete , "smoothness"), lead yellow , royal yellow , Neugelb , Gold smoothness ( spuma auri , reddish oxide), silver foam ( spuma argenti ), silver smoothness (from Middle High German silver glete ; lead oxide of light color), lithargyrum and silver ash , finely ground lead oxide was also used as a pigment - or converted with nitric acid and dichromate solution to form the pigment chrome yellow ( lead chromate ). Massicotit has good hiding power , but is not very stable. If it is exposed to air ( containing hydrogen sulfide ) , it turns blackish-brown, which is attributable to the formation of lead (II) sulfide . It is also sensitive to acids and bases . Massicotit was used very early, mainly because of its siccative effect on linseed oil and other oily binders ( oil painting ). At the end of the Middle Ages it was replaced by the more stable lead-tin-yellow ( lead- tinate ).

Slippery lead or slippery silver was also used earlier for medicinal plaster ( lead plaster , diaquilon ).

safety instructions

With repeated exposure, effects on the blood, kidneys and central nervous system are possible ( lead poisoning ). Formation of anemia , dysfunction. A severe impairment of fertility is also possible.

Individual evidence

1. ↑ Entry on lead oxide. In: Römpp Online . Georg Thieme Verlag, accessed on December 9, 2014.
2. ↑ ^{a b c d} data sheet lead (II) oxide (PDF) from Merck , accessed on January 19, 2011.
3. ↑ ^{a b} Entry on lead (II) oxide in the GESTIS substance database of the IFA , accessed on January 8, 2020(JavaScript required) .
4. ↑ 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 named in this annex in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on December 14, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
5. ↑ Entry in the SVHC list of the European Chemicals Agency , accessed on July 17, 2014.
6. ^ Arnold Willmes, Pocket Book Chemical Substances , Harri Deutsch, Frankfurt (M.), 2007.
7. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 91st – 100th, improved and greatly expanded edition. Walter de Gruyter, Berlin 1985, ISBN 3-11-007511-3 .
8. ↑ Lead plaster in Meyers Großes Konversations-Lexikon, Leipzig 1905. Vol. 3, p. 48.
9. ↑ Jürgen Martin: The 'Ulmer Wundarznei'. Introduction - Text - Glossary on a monument to German specialist prose from the 15th century. Königshausen & Neumann, Würzburg 1991 (= Würzburg medical-historical research. Volume 52), ISBN 3-88479-801-4 (also medical dissertation Würzburg 1990), p. 119 ( blīglete ; "litagirum (that is silverglet or blyglett)"), 125 ( dyaquilon : lead oxide plaster ), 134 ( glete : black lead, lead oxide, possibly also lead acetate) and 172 ( silver ash , silver glete ).