Lead IV Complexes

When Pb02 is dissolved in cold cone. HCl, H2PbCl6 is formed in solution and its ammonium salt can be precipitated by adding ammonium chloride. Cone, sulphuric acid reacts with the complex precipitated, forming the covalent lead tetrachloride. 

To some Pb02 in a boiling tube, cooled in ice/salt mixture, add cone. HCl with shaking until the solid dissolves. Prepare a concentrated ammonium chloride solution, cool it in an ice bath and add the solution slowly to the acid solution until enough is added to precipitate the complex compound. 

Carefully add cone, sulphuric acid to the complex and note the formation of an oiMike compound. Divide the separated oil into two portions add water to a portion note the changes occurring and test with a pH stick. Add tetrachloromethane to the second portion and shake. Draw your conclusions. 

Like other elements in this group (except C), Pb(IV) forms octahedral hexahalo-complexes which are precipitated with large cations. When lead(II) chloride, 

Weigh out about 0.2 g of your preparation into a beaker, add water with continuous stirring until the solid is transformed to the dark lead(IV) oxide. Filter through a G4 crucible, wash with water and dry at 105 C to constant weight. Calculate from duplicate results, the % purity of your preparation. 

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Highly explosive red crystals were deposited by the action of (NH4)2PbCl6 upon sodium azide solution and, though not analysed, a lead(IV) complex azide was believed present226. 

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