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 Hydroxides

Two forms of lead hydroxide are known: 2PbO.H2O or Pb2O(OH)2, and 3PbO.H2O or Pb3O2(OH)2; the ortho-hydroxide, Pb(OH)2, appears to be unknown in the solid state.

Pb2O(OH)2 is formed by the action of water containing dissolved oxygen on metallic lead; by precipitating lead acetate or other lead salt solution by alkali hydroxide or ammonia; and also by allowing a solution of lead oxide in potassium hydroxide to stand in the air, when the absorbed carbon dioxide displaces hydrated lead oxide from combination with alkali, so that Pb2O(OH)2 separates in quadratic crystals.

Pb3O2(OH)2 is prepared from the corresponding basic acetate, Pb3O2(C2H3O2)2, by mixing its saturated aqueous solution with ammonia, and allowing the solution to stand at 25°-30° C., with careful exclusion of air. The hydroxide then separates in shining octahedra. A product of the same composition is obtained by precipitating a lead salt solution with caustic alkali, and drying the precipitate at 100° C., and also by precipitating a lead salt with baryta water at atmospheric temperature.

Lead hydroxide is distinctly soluble in water, to which it imparts an alkaline reaction. A saturated solution of Pb3O2(OH)2 at 18° C. contains, according to Pleissner, 100.5 m.g. PbO per litre. Ruer has found, by the conductivity method, that the solubilities in water at 22° C. of the various forms of lead oxide, with the exception of Geuther's red oxide which is less soluble, lie between 1.00×10-4 and 1.12×10-4 gram-equivalents per litre; whilst Herz has calculated the solubility lead hydroxide at 25° C. to be 0.93×10-4. At 130° C. lead hydroxide loses all its water, being converted into the oxide.

It has already been stated that lead monoxide is an amphoteric oxide; thus the hydroxide behaves both as a weak base and a weak acid.

It is possible that in a solution of lead hydroxide in water, which is alkaline in reaction and therefore contains hydroxyl ions, ionisation has proceeded in two stages, thus:

  1. Pb(OH)2Pb(OH) + OH'
  2. Pb(OH)Pb•• + OH'.

From the work of Berl and Austerweil, however, it appears that only the first reaction is to be considered as taking place, and that ionisation has proceeded to the extent of about 28 per cent. The same authors have determined the solubility of lead oxide in sodium hydroxide solutions of different concentrations and temperatures, and conclude that when the alkali solution is below normal strength the sodium salt HPbOONa of the monobasic acid HPbOOH is produced in solution, but that with more concentrated alkali solutions the sodium salt Pb(ONa)2 of the dibasic acid Pb(OH)2 is formed to some extent. Thus, towards weak alkalis lead hydroxide behaves as if it were ionised thus:

Pb(OH)2PbO2H' + H;

and the dissociation constant of this acid at 18° C. is found to be 1.1×10-12, which shows lead hydroxide to be a weaker acid than phenol.

Hantzsch, however, finds no evidence that hydroxides of the type M(OH)2 can behave as dibasic acids, and regards their salts as always derived from acids of the formic acid type HMOOH. Moreover, he has shown that the hydroxides of lead, tin, and germanium are feeble acids whose strengths increase in the order in which the metals are named.

Lead monoxide dissolves in lime and baryta water, forming yellow solutions, and also in strong solutions of calcium and strontium chloride. Lead hydroxide combines with polyhydric alcohols and hydroxy-carboxylic acids to form complex compounds in solution in which the lead is very little ionised. Alkali plumbite solution is used as a mordant in cotton dyeing.

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