Tin chemicals of industrial importance include the halides, particularly the chlorides, of both tin(II) and tin(IV), the salts used in electroplating-tin(II) sulphate and fluoroborate and the alkali stannates — and also tin(II) octate which is used as a catalyst in the production of polyurethanes. As most tin(II) salts are oxidised on exposure to air, commercial material can be expected to contain small amounts of tin(IV) and in their analysis a knowledge of both tin(II) and tin(IV) content may be necessary. While the tin(II) content can readily be found by direct titration with iodate, there exist no reliable methods for the determination of the accompanying small amounts of tin(IV) and the most accurate procedure involves careful determination of tin(II) and of total tin, the amount of tin(IV) being found by difference.
Unable to display preview. Download preview PDF.