Lead(II) chromate
 |
|
 |
|
| Names | |
|---|---|
| Other names
see text
|
|
| Identifiers | |
| ChEBI | |
| ECHA InfoCard | 100.028.951 |
| EC Number | 231-846-0 |
|
PubChem CID
|
|
| RTECS number | GB2975000 |
| UN number | 3288 |
| Properties | |
| PbCrO4 | |
| Molar mass | 323.2 g/mol |
| Appearance | orange-yellow powder |
| Density | 6.12 g/cm3, solid |
| Melting point | 844 °C (1,551 °F; 1,117 K) |
| negligible | |
| Solubility | soluble in diluted nitric acid insoluble in acetic acid, ammonia |
| −-18.0·10−6 cm3/mol | |
|
Refractive index (nD)
|
2.31 |
| Structure | |
| monoclinic | |
| Hazards | |
| Safety data sheet |
ICSC 0003 Sigma-Aldrich |
| GHS pictograms |
 
|
| GHS signal word | Danger |
| H350, H360, H373, H410 | |
| P201, P273, P308+313, P501 | |
| NFPA 704 | |
| Lethal dose or concentration (LD, LC): | |
|
LD50 (median dose)
|
>12 g/kg (mouse, oral) |
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
|
 (what is   ?) |
|
| Infobox references | |
Lead(II) chromate (PbCrO4) is a chemical compound, a chromate of lead. It has a vivid yellow color and is insoluble in water, and as a result, is used in paints under the name chrome yellow.
Lead(II) chromate may also be known as chrome yellow, chromic acid lead(II) salt, canary chrome yellow 40-2250, chrome green, chrome green UC61, chrome green UC74, chrome green UC76, chrome lemon, crocoite, dianichi chrome yellow G, lemon yellow, king's yellow, Leipzig yellow, lemon yellow, Paris yellow, pigment green 15, plumbous chromate, pure lemon chrome L3GS, and various other names. The mineral crocoite, occurring as orange-yellow prismatic crystals, is a moderately rare mineral known from the oxidation zones of such Pb ore beds, that were affected by chromate-bearing solutions, coming from the oxidation of primary Cr minerals (chromite) of the nearby (ultra)mafic rocks.
Lead chromate adopts the monazite structure, meaning that the connectivity of the atoms is very similar to other compounds of the type MM'O4. Pb(II) has a distorted coordination sphere being surrounded by eight oxides with Pb-O distances ranging from 2.53 to 2.80 Å. The chromate anion is tetrahedral, as usual.
Approximately 37,000 tons were produced in 1996. The main applications are as a pigment in paints. It has also been used in the paint to color school buses.
Lead chromate is used in some pyrotechnic compositions, especially delay compositions, as an oxidizer.
Lead(II) chromate can be produced by treating sodium chromate with lead salts such as lead(II) nitrate or by combining lead(II) oxide with chromic acid. Related pigments are produced by the addition of sulfate, resulting in a mixed lead-chromate-sulfate compositions.
...
Wikipedia