Lead, carbonate chromate

The carbonates, sulfates, nitrates, and haUdes of lead (except the yeUow iodide) are colodess. Bivalent lead forms a soluble nitrate, chlorate, and acetate a slightly soluble chloride and an insoluble sulfate, carbonate, chromate, phosphate, molybdate, and sulfide. Highly crystalline basic lead salts of both anhydrous and hydrated types are readily formed. Tetrabasic lead sulfate [52732-72-6] 4PbO PbSO, and the hydrated tribasic salt [12397-06-7] ... 

Lead chromates are prepared by precipitation techniques from soluble salts ia aqueous media. The raw material Hst iacludes a number of different lead compounds, eg, Htharge, lead nitrate, basic lead acetate, basic lead carbonate, as well as acids, alkahes, sodium bichromate, and sodium chromate. The typical reaction can be represented by the foUowiag equation ... 

Lead-calcium-silver anodes, 74 777 Lead-calcium-tin alloys, 74 775-776 Lead carbonates, 74 794-795 Lead chalcogenides, 79 157 Lead chloride, 74 785 Lead chromate... 

Electrolytic production of white lead is based on this principle during this process the lead anode is immersed in a solution of alkali chlorate or acetate with a small quantity of alkali carbonate. In the course of electrolysis the lead is dissolved and forms at first a soluble chlorate or acetate the ions Pb++ diffuse and migrate into the bulk of the solution where the necessary amount of OH- and CO3 ions is found with which they react and precipitate as insoluble, basic lead carbonate. The solution is thus deprived of the carbonate ions which are then supplemented by a continuous absorption of carbon dioxide in the electrolyte. By using chromate, instead of carbonate chromium yellow is formed. Analogously also zinc white could be produced. 

Lead chromates and lead molybdates are produced by precipitation of soluble salts in aqueous media. Various lead sources include litharge, lead nitrate, basic lead actetate, and lead carbonate. The lead carbonate and basic lead acetate are used primarily to control particle size. Other ingredients include acids, alkalis, sodium bichromate, and sodium chromate. Additionally, molybdate orange manufacture involves the use of sodium molybdate and sodium sulfate as raw materials. 

J)) Mix equal small quantities of potassium carbonate, potassium nitrate, and powdered chrome alum, place the mixture on a platinum foil, and hold it with the forceps in the upper Bunsen flame so that the mixture will fuse. If a platinum foil is not available, use a porcelain crucible. A yellow mass, due to the presence of potassium chromate, results. If the color is not decided, dissolve the mass in water, add acetic acid, slowly at first, and boil to expel the carbon dioxide. Add a few drops of lead nitrate solution to a portion, and yellow lead chromate is precipitated. (Compare Exp. 177 (e).) If the precipitate is white, it is lead carbonate, and shows that not all the potassium carbonate was decomposed, as intended. 

Lead compounds were once widely used also for paints. They were in great demand because they covered surfaces well and were available in a number of vivid colors. Among these were lead chromate (yellow), lead molybdate (reddish-orange), lead(II) oxide (canary yellow), red lead oxide (Pb304 red), and white lead, a complex lead carbonate/lead hydroxide mixture. As with other lead compounds, however, the potential health hazards of the element have greatly reduced the availability of lead-based paints. 

International Labour Organization, International Occupational Safety and Health Information Centre (CIS) Lead, ICSC 0052, 2002 Lead (II) Oxide, ICSC 0288, 2003 Lead Dioxide, ICSC 1001, 2002 Lead Tetroxide, ICSC 1002, 2002 Lead Carbonate, ICSC 0999, 2001 Lead Chromate, ICSC 0003, 2003, Geneva, Switzerland. 

Stabilizers for polyvinyl chloride Pigments such as basic lead carbonate (in white house paint), red lead (in primer paint for steel), lead chromate... 

Dichromate of Dead. Boil pure carbonate of lead with chromate of potassa in execs. , tmtU it assumes a proper red color then wash it with pure water, and diy it in the shade. This is the pigment known as ehrotne-red, (See Ko, 2708.)... 

Bichromate of lead, 2 Pb 0 -H Cr 0, is found native, as the red-lead ore, forming beautiful red crystals. It may also be formed by fusing the neutral chromate of lead with nitrate of potash, or by boiling carbonate of lead with chromate of potash and is much used as a paint. 

F. Kuhlmann, C. 0. Weber, and A. Winterfeld obtained lead chromate by the action of potassium chromate or dichromate on white-lead, or lead carbonate. H. Golblum and G. Stofiella studied the system PbC03- -K2Cr04 PbCr04... 

Na2Cr04 in the presence of lead chromate, oxychromate and carbonate, are shown in Fig. 60. The region where lead carbonate is stable is very small, and the transformation PbCr04-fNa2C08 PbC03-fNa2Cr04 occurs only in the presence of hydrocarbonate. The regions of -stability of the two lead chromates are very wide. 

Lead-based paint with lead carbonate is bioavailable (highly soluble in bodily fluids), while lead chromate has very low bioavailability, with no carcinogenic potential. 

Kerosene Lacquer solvents Lacquers Lactic acid, cold Lactic acid, hot Laurie acid Lead, molten Lead acetate Lead arsenate Lead bromide Lead carbonate Lead chloride Lead chromate Lead dioxide Lead nitrate Lead oxide Lime bleach Lime sulfur Linoleic acid Linseed oil Lithium carbonate Lithium chloride Lithium hydroxide Lithium nitrate Lithium nitrite... 

Some lead pigments and their respective colors include lead carbonate 2PbC03 Pb(OH)2 (white), lead chromate PbCrO, (orange, red, and yellow), and lead oxide PbO (scarlet, red). 

Concrete is an alkaline environment where iron passivates and the amphoteric materials, aluminum and zinc, react with fresh concrete by evolving hydrogen. In the case of zinc, the reaction can be quenched by addition of chromates to the canent or prepassivating the zinc used as a protective layer for reinforcing iron bars in concrete. Lead in concrete, in conditions of high humidity, corrodes, and the concrete prevents the formation of the protective layers of basic lead carbonate, which would be formed in its absence. 

Lead carbonate dibasic. See Lead carbonate Lead chromate... 

Ferric oxide Pigment green 8 Ultramarine blue Wollastonite pigment, ceramic coatings Lead chromate pigment, ceramic glazes Cadmium Cadmium sulfide Lead carbonate basic... 

Write a formula for each ionic compound. (a) copper(II) bromide (b) silver nitrate (c) potassium hydroxide (d) sodium sulfate (e) potassium hydrogen sulfate (f) sodium hydrogen carbonate 70. Write a formula for each ionic compoimd. (a) copper(l) chlorate (b) potassium permanganate (c) lead(ll) chromate (d) calcium fluoride (e) iron(ll) phosphate (f) lithium hydrogen sulfite... 

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