Chemical elements
    Physical Properties
    Chemical Properties
      Lead Tetramethyl
      Lead Tetraethyl
      Lead Tetraphenyl
      Lead Ethoxide
      Lead Fluoride
      Lead Tetrafluoride
      Hydrofluoplumbic Acid
      Lead Chloride
      Lead Chloride Double Salts
      Basic Lead Chlorides
      Lead Tetrachloride
      Ammonium Plumbichloride
      Lead Chlorite
      Lead Chlorate
      Lead Perchlorate
      Lead Dibromide
      Double Salts of Lead Bromide
      Basic Lead Bromides
      Lead Bromate
      Lead Iodide
      Lead Iodide Complex Salts
      Basic Lead Iodides
      Lead Tetra-iodide
      Lead Iodate
      Lead Periodates
      Lead Suboxide
      Lead Monoxide
      Lead Hydroxides
      Lead Dioxide
      Plumbic Acids
      Hexahydroxyplumbic Acid
      Colloidal Plumbic Acid
      Potassium Plumbate
      Lead Plumbate
      Calcium Orthoplumbate
      Lead Orthoplumbate
      Red Lead
      Metaplumbic Acid
      Calcium Metaplumbate
      Lead Metaplumbate
      Basic Lead Plumbate
      Lead Sulphide
      Lead Sulphohalides
      Lead Polysulphide
      Lead Sulphite
      Lead Sulphates
      Lead Sulphate
      Basic Lead Sulphates
      Lead Hydrogen Sulphate
      Plumbic Sulphate
      Lead Persulphate
      Lead Thiosulphate
      Lead Dithionate
      Lead Selenide
      Lead Selenite
      Lead Selenate
      Lead Telluride
      Lead Tellurite
      Lead Azide
      Lead Azoimide
      Lead Hydrazoate
      Lead Imide
      Lead Hyponitrite
      Lead Nitrites
      Lead Nitrate
      Lead saltpetre
      Basic Lead Nitrates
      Lead Hypophosphite
      Lead Phosphite
      Lead Orthophosphate
      Lead Monohydrogen Phosphate
      Lead Dihydrogen Phosphate
      Lead Pyrophosphate
      Lead Metaphosphate
      Lead Arsenite
      Lead Orthoarsenate
      Lead Hydrogen Arsenate
      Lead Pyroarsenate
      Lead Antimonate
      Lead Carbonate
      White Lead
      Lead Formate
      Lead Acetate
      Sugar of Lead
      Complex Lead Acetates
      Plumbic Acetate
      Lead Tetra-acetate
      Lead Oxalate
      Lead Tartrate
      Lead Silicates
      Lead Borates
      Normal Lead Chromate
      Lead Dichromate
      Basic Lead Chromate
      Lead Molybdate
      Lead Tungstate
      Lead Metatungstate
      Lead Diuranate
      Lead Peruranate
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Lead Carbonate, PbCO3

The natural form of Lead Carbonate, PbCO3, is cerussite, which occurs in rhombic crystals isomorphous with aragonite, CaCO3; strontianite, SrCO3, and witherite, BaCO3. Lead carbonate is also a constituent of phosgenite, PbCO3.PbCl2, and of leadhillite, 2PbCO3.PbSO4.Pb(OH)2. The normal salt may be prepared artificially by precipitating a cold solution of lead acetate or nitrate with ammonium carbonate, or by passing carbon dioxide into a dilute solution of lead acetate. If formed sufficiently slowly lead carbonate separates in the crystalline state. It has been shown by Altmann, however, that a basic carbonate of the composition of white lead 2PbCO3.Pb(OH)2 may also be precipitated. Its formation is due to the previous hydrolysis of the lead acetate, which is promoted by dilution and raising the temperature, and especially by carrying out the reaction at 100° C. under a reflux condenser, so that vapourised acetic acid can escape. From lead nitrate solution carbonate is not precipitated by carbon dioxide. Crystallised lead carbonate has a density of 6.47, that of the amorphous salt being 6.43. The molecular heat of formation of the crystallised salt from its elements is 169,800 calories (Thomsen), or 166,700 calories (Berthelot). Lead carbonate is dissociated by heat in the sense of the reaction:

PbCO3PbO + CO2.

According to Debray the reaction is not reversible, but Colson has shown that the white oxide formed by the decomposition of lead carbonate, PbCO3, at as low a temperature as possible absorbs carbon dioxide readily, though the yellow oxide formed by heating the carbonate to 350° C. has not this property, probably because it is polymerised. Thus the reaction is reversible if the disturbance due to polymerisation is eliminated; and a little water-vapour has been found greatly to accelerate the establishment of equilibrium between lead carbonate and its dissociation products. The following are the dissociation pressures of lead carbonate when dry and also when moist:

Temperature ° C.184210233280285
Dissociation Pressure, mm. Hg. (dry)1032.5102548760
Dissociation Pressure, mm. Hg. (moist)1233104--

Lead carbonate is very slightly soluble in pure water; 1 litre of water dissolves 0.0011 to 0.0017 gram PbCO3 at 20° C., according to measurements of electric conductivity. There is no hydrolysis below 70° C., but at that temperature the water begins to show an alkaline reaction; and if air free from carbon dioxide is drawn through the liquid so as to remove the liberated carbon dioxide, the carbonate is changed into the basic salt 2PbCO3.Pb(OH)2.

Lead carbonate is much more soluble in water containing dissolved carbon dioxide than in pure water, as the following figures show (Pleissner), t = 18° C.:

Mgms. CO2 per litre.
Mgms. PbC03 per litre.1.756.

The interaction of lead carbonate and solutions of alkali carbonates has been investigated by Auerbach and Pick.

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