Sodium plumbate

Here lead compound remains in solution in the fomi of sodium plumbate. Careful acidification of the solution with nitric acid leads to the formation of lead azide. 

Properties White to light-tan crystals. Soluble in water insoluble in alcohol decomposes in air aqueous solution slightly alkaline loses 311,0 at 140C. Derivation (1) By fusion of metastannic acid and sodium hydroxide, (2) by boiling tin scrap and sodium plumbate solution. 

A stainless steel shaker tube charged with benzene and finely powdered sodium plumbate>sodium hydroxide (1 10) prepared from PbO and NaOH, cooled to Dry Ice temp., isobutylene weighed in, 1000 p. s. i. air pressure added at room temp., and shaken 3 hrs. at 200° ... 

After mineralization with sodium 1 — 2 drops of a freshly prepared l% sodium nitroprusside solution (Na2[Fe(CN)5NO] 3H2O) are added to the filtrate (0.5 ml). If a red color is formed, proving the presence of sulfur in the tested sample, 2—3 drops of sodium plumbate are added to another 0.5 ml portion of the solution (to a 5% solution of lead acetate, 20% sodium hydroxide is added dropwise until the initially-formed precipitate is again dissolved). The formation of a black precipitate proves the presence of sulfur in the molecule of the substance tested, a brown precipitate indicates the presence of sulfur-containing impurities in the sample. 

Lead dioxide reacts with alkalies forming various types of plumbates. Fusion with caustic soda or caustic potash yields orthoplumbates and meta-plumbates, such as Na4Pb04 or Na2Pb03 (or the corresponding potassium salts). However, when dissolved in a concentrated aqueous solution of sodium or potassium hydroxide, the product is hydroxyplumbate ... 

A. Baudrimont and J. Pelouze (1833) fused the sodium sulphate with galena or zinc blende and formed the alkali plumbate or zincate, and J. B. M. P. Closson boiled a soln. of sodium sulphate with milk of lime and lead oxide. The plumbate can be decomposed by sulphide, carbon dioxide, or by electrolysis. The St. Gobain Co. patented a process in which sand, coal, and sodium sulphate are heated together water-glass is formed and a soln. or suspension of that salt in water is decomposed by carbon dioxide or by milk of lime. J. Simpson (1890), J. C. Ody (1892), N. Basset and W. von Baranofi (1894) decomposed a soln. of sodium sulphate by calcium phosphate in dil. acid. The soluble sodium phosphate which is formed... 

Stable hydrosols may be obtained similarly by reduction of arsenious oxide, dissolved in aqueous sodium hydroxide containing some other protective colloid such as gelatin or egg-albumin, by means of alkaline pyrogallol.6 Salts of metallic acids, such as sodium antimonate or calcium plumbate,-with or without the addition of protalbic acid, may also be employed as protective colloids.1... 

Add sodium hydroxide solution to a solution of a zinc, an aluminium or a lead salt. The hydroxide will precipitate and then dissolve in excess alkali to form an aluminate, zincate or plumbate. On the... 

C. i1. Burgess1 and C. Hambuechen, in 1903, investigated the various conditions requisite for the electrolytic production of a good white lead. They found that a two-compart-ment cell is necessary to obtain a pure product. When lead anodes and sodium nitrate solution are employed a certain quantity of basic lead salt is produced, and there is not therefore a 100 per cent, formation of pure lead nitrate. The reduction of sodium nitrate at copper cathodes cannot be prevented so that a certain amount of ammonia is formed, and the solution being alkaline after a time, plumbates are formed and a layer of spongy lead is deposited on the cathode. If, therefore, the cathode compartment be not separated from the anode, the loosely-deposited cathodic lead will fall into the white lead which is collecting at the bottom of the cell. 

Plumbate of soda Red lead oxlde dissolved In sodium hydroxide. 

An example of separation of overlapping waves is the analysis of mixtures of lead(II) and thallium(I). A mixture of these two ions in neutral media gives a wave that cannot be resolved into the individual waves of Pb and Tl the half-wave potentials differ by only about 60 mV. When excess sodium hydroxide is added, the wave for thalUum(I) remains at virtually the same potential as in neutral media (as thallium does not form hydroxo complexes), whereas the wave of lead(II) is shifted to more negative potential by about 300 mV, due to formation of plumbate (Fig. 

A more sensitive test is attained by the use of sodium tetrahydroxo-plumbate(II) solution, prepared by adding sodium hydroxide to lead acetate until the initial precipitate of lead hydroxide has just dissolved ... 

Aluminium and lead(ll) ions react in a similar manner with sodium hydroxide solution, forming white precipitates which react with excess sodium hydroxide solution to form complex salts (aluminate and plumbate), which dissolve to give colourless solutions. 

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