Lead(II,IV) oxide

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











































Lead(II,IV) oxide, also called red lead is the inorganic compound with the formula Pb3O4. A bright red or orange solid, it is used as pigment, in the manufacture of batteries, lead glass, and rustproof primer paints. It is an example of a mixed valence compound, being composed of both Pb(II) and Pb(IV).[2]




Contents





  • 1 Structure


  • 2 Preparation


  • 3 Reactions


  • 4 Use


  • 5 Physiological effects


  • 6 History


  • 7 See also


  • 8 References


  • 9 External links




Structure


Lead(II,IV) oxide has a tetragonal crystal structure at room temperature, which transforms to an orthorhombic (Pearson symbol oP28, Space group = Pbam, No 55) form at temperature 170 K (−103 °C). This phase transition only changes the symmetry of the crystal and slightly modifies the interatomic distances and angles.[3]





  • Unit cell of tetragonal Pb3O4
    (Key:      Pb      O)







  • Part of tetragonal red lead's crystal structure





Preparation


Lead(II,IV) oxide is prepared by calcination of lead(II) oxide (PbO; also called litharge) in air at about 450-480 °C:[4]


6 PbO + O2 → 2 Pb3O4

The resulting material is contaminated with PbO. If a pure compound is desired, PbO can be removed by a potassium hydroxide solution:


PbO + KOH + H2O → K[Pb(OH)3]

Another method of preparation relies on annealing of lead(II) carbonate (cerussite) in air:


6 PbCO3 + O2 → 2 Pb3O4 + 6 CO2

Yet another method is oxidative annealing of white lead:


3 Pb2CO3(OH)2 + O2 → 2 Pb3O4 + 3 CO2 + 3 H2O

In solution, lead(II,IV) oxide can be prepared by reaction of potassium plumbate with lead(II) acetate, yielding yellow insoluble lead(II,IV) oxide monohydrate, Pb3O4·H2O, which can be turned into the anhydrous form by gentle heating:


K2PbO3 + 2 Pb(OCOCH3)2 + H2O → Pb3O4 + 2 KOCOCH3 + 2 CH3COOH

Natural minium is uncommon, forming only in extreme oxidizing conditions of lead ore bodies. The best known natural specimens come from Broken Hill, New South Wales, Australia, where they formed as the result of a mine fire.[5]



Reactions


Red lead is virtually insoluble in water and in ethanol. However, it is soluble in hydrochloric acid present in the stomach, and is therefore toxic when ingested. It also dissolves in glacial acetic acid and a diluted mixture of nitric acid and hydrogen peroxide.


When heated to 500 °C, it decomposes to lead(II) oxide and oxygen. At 580 °C, the reaction is complete.


2Pb3O4 → 6 PbO + O2

Nitric acid dissolves the lead(II) oxide component, leaving behind the insoluble lead(IV) oxide:


Pb3O4 + 4 HNO3 → PbO2 + 2 Pb(NO3)2 + 2 H2O

With iron oxides and with elemental iron, lead(II,IV) oxide forms insoluble iron(II) and iron(III) plumbates, which is the basis of the anti-corrosive properties of lead-based paints applied to iron objects.



Use


Lead tetraoxide is most often used as a pigment for primer paints for iron objects. Due to its toxicity, its use is being limited. In the past, it was used in combination with linseed oil as a thick, long-lasting anti-corrosive paint. The combination of minium and linen fibres was also used for plumbing, now replaced with PTFE tape. Currently it is mostly used for manufacture of glass, especially lead crystal glass. It finds limited use in some amateur pyrotechnics as a delay charge and was used in the past in the manufacture of dragon's egg pyrotechnic stars.


Red lead is used as a curing agent in some polychloroprene rubber compounds. It is used in place of magnesium oxide to provide better water resistance properties.


Red lead was used for engineer's scraping, before being supplanted by engineer's blue.


It is also used as an adultering agent in turmeric powder .



Physiological effects


Main article: Lead poisoning

When inhaled, lead(II,IV) oxide irritates lungs. In case of high dose, the victim experiences a metallic taste, chest pain, and abdominal pain. When ingested, it is dissolved in the gastric acid and absorbed, leading to lead poisoning. High concentrations can be absorbed through skin as well, and it is important to follow safety precautions when working with lead-based paint.


Long-term contact with lead(II,IV) oxide may lead to accumulation of lead compounds in organisms, with development of symptoms of acute lead poisoning. Chronic poisoning displays as agitation, irritability, vision disorders, hypertension, and also a grayish facial hue.


Lead(II,IV) oxide was shown to be carcinogenic for laboratory animals. Its carcinogenicity for humans was not proven.




Minium from a mine fire at Broken Hill, Australia



History


This compound's Latin name minium originates from the Minius, a river in northwest Iberia where it was first mined.


Lead(II,IV) oxide was used as a red pigment in ancient Rome, where it was prepared by calcination of white lead. In the ancient and medieval periods it was used as a pigment in the production of illuminated manuscripts, and gave its name to the minium or miniature, a style of picture painted with the colour. As a finely divided powder, it was also sprinkled on dielectric surfaces to study Lichtenberg figures.


In traditional Chinese medicine, red lead is used to treat ringworms and ulcerations, though the practice is limited due to its toxicity. Also, azarcón, a Mexican folk remedy for gastrointestinal disorders, contains up to 95% lead(II,IV) oxide.[6]



See also


  • Lead paint


  • Lead(II) oxide, PbO


  • Lead(IV) oxide, PbO2

  • List of inorganic pigments


References




  1. ^ "VOLUNTARY RISK ASSESSMENT REPORT ON LEAD AND SOME INORGANIC LEAD COMPOUNDS". Retrieved 2012-12-25. 


  2. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9. 


  3. ^ Gavarri, J; Weigel, Dominique; Hewat, A. W. (1978). "Oxydes de plomb. IV. Évolution structurale de l'oxyde Pb3O4 entre 240 et 5 °K et mécanisme de la transition" [Lead oxides. IV. Structural evolution of the oxide Pb3O4 between 240 and 5 K and mechanism of transition]. Journal of Solid State Chemistry. 23 (3–4): 327. doi:10.1016/0022-4596(78)90081-6. 


  4. ^ Carr, Dodd S. (2005), "Lead Compounds", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a15_249 


  5. ^ Minium


  6. ^ Bose, A.; Vashistha, K; O'Loughlin, B. J. (1983). "Azarcón por empacho – another cause of lead toxicity". Pediatrics. 72: 108–118. 




External links


  • National Pollutant Inventory - Lead and Lead Compounds Fact Sheet

  • Minium mineral data

Lead(II,IV) oxide

Sample of pulverised lead(II,IV) oxide
Names

Preferred IUPAC name
Lead tetroxide [1]

Other names
Minium, red lead, triplumbic tetroxide

Identifiers

CAS Number



  • 1314-41-6 ☑Y


3D model (JSmol)


  • Interactive image


ChemSpider


  • 21169908 ☑Y


ECHA InfoCard

100.013.851

EC Number
215-235-6


PubChem CID


  • 16685188


UN number
1479




Properties

Chemical formula


Pb
3O
4

Molar mass
685.6 g mol−1
Appearance
Vivid orange crystals

Density
8.3 g cm−3

Melting point
500 °C (decomposition)

Vapor pressure
1.3 kPa (at 0 °C)
Structure

Crystal structure


Tetragonal, tP28

Space group

P42/mbc, No. 135
Hazards

GHS pictograms

The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The environment pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)

GHS signal word

DANGER

GHS hazard statements


H272, H302, H332, H360, H373, H410

GHS precautionary statements


P201, P220, P273, P308+313, P501

NFPA 704



Flammability code 0: Will not burn. E.g., waterHealth code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gasReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond

0


3


0




Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).


☑Y verify (what is ☑Y☒N ?)

Infobox references









  • v

  • t

  • e



Lead compounds

Pb(II)

  • PbBr2

  • Pb(C5H5)2

  • Pb(C2H3O2)2

  • PbCl2

  • PbCO3

  • PbCrO4

  • PbF2

  • PbHAsO4

  • PbI2

  • Pb(NO3)2

  • Pb(N3)2

  • PbO

  • Pb(OH)2

  • Pb3(PO4)2

  • PbS

  • Pb(SCN)2

  • PbSe

  • PbSO4

  • PbTe

  • PbTiO3

  • plumbite


  • PbC2 (hypothetical)

Pb(II,IV)

  • Pb3O4
Pb(IV)

  • Pb(C2H3O2)4

  • PbCl4

  • PbF4

  • PbH4

  • PbO2

  • PbS2

  • plumbate


  • Pb(OH)4 (hypothetical)






Comments

Post a Comment

Popular posts from this blog

Executable numpy error

Image
Clash Royale CLAN TAG #URR8PPP Executable numpy error I'm trying to create an executable file for my code. I've already tried with cx_Freeze and with pyinstaller. Both gives me the same error, which is: "Missing required dependencies 0.format(missing_dependencies))" PS C:UsersGustavoDesktopbuildexe.win32-3.6> python AgendaOficial.py C:UsersGustavoAppDataLocalProgramsPythonPython36-32python.exe: can't open file 'AgendaOficial.py': [Errno 2] No such file or directory PS C:UsersGustavoDesktopbuildexe.win32-3.6> .AgendaOficial.exe Traceback (most recent call last): File "C:UsersGustavoAppDataLocalProgramsPythonPython36-32libsite-packagescx_Freezeinitscripts__startup__.py", line 14, in run module.run() File "C:UsersGustavoAppDataLocalProgramsPythonPython36-32libsite-packagescx_FreezeinitscriptsConsole.py", line 26, in run exec(code, m. dict ) File "AgendaOficial.py", line 8, in File "C:UsersGustavoAppDataLocal...
Read more

Trying to Print Gridster Items to PDF without overlapping contents

Image
Clash Royale CLAN TAG #URR8PPP Trying to Print Gridster Items to PDF without overlapping contents I want to print gridster items to pdf using chome browser. Unfortunately the item overlaps on next page. Is there any way to make gridster item go to next page if it doesnt fit in the current page when printing to pdf? Screenshot By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.
Read more

Mass disable jenkins jobs

Image
Clash Royale CLAN TAG #URR8PPP Mass disable jenkins jobs Is it possible to disable a large number of Jenkins jobs in one go? I have a large number of jenkins job I need to disable. Visiting each job in turn and disbling is tedious. 2 Answers 2 https://wiki.jenkins-ci.org/display/JENKINS/Configuration+Slicing+Plugin That works beautifully install it go to http://your_jenkins.com:8080/slicing/jobdisabledbool/? By using configuration slicing plugin: By using this plugin easy to find out anything has enabled or disable jobs and timer separated jobs Manage Jenkins >Config slicing > select options By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.
Read more