Tin is one of the important metals used in early civilizations.SnO is obtained by thermal decomposition of stannous oxalate in absence of air. Sn also formed stable divalent oxide with the molecular formula SnO. The amphoteric nature of Sn is shown by its reaction with fused sodium hydroxide and concentrated sulfuric acid. It is a white color solid and amphoteric in nature. Tin occurs in nature largely as cassiterite or tinstone (SnO 2). The dihalide, SnF 2 has been used in toothpaste but presently it is replaced by NaF due to the toxic nature of Sn. Therefore, Sn forms all the stable dihalides. SnCl 4 and SnBr 4 are colorless liquids while SnI 4 is a bright orange solid.Īs mentioned earlier, the divalent state of Sn is more stable than the tetravalent state. The other SnX 4 compounds are best made by the direct union of metal and halide. SnF 4 is a hygroscopic white solid formed by treating SnCl 4 with anhydrous HF. Except for SnF 4, all these halides are formed by covalent bonding with volatile in nature. HalidesĪll four tetrahalides of tin are known. It is used for the transformation of benzaldehyde to benzyl alcohol or nitrobenzene to aniline. SnH 4 is a good reducing agent in organic chemistry. But it is also decomposed by concentrated acids or alkalis. SnH 4 decomposes slowly at room temperature and is passive towards dilute aqueous acids and alkalis. The stability of the group-14 hydrides decreases sharply from Ge to Pb. Chemical Compounds Tin hydrideĪll the elements of group-14 form gaseous hydrides like MH 4. It is a p-block element that lies in between germanium and lead in the periodic table. Tin is found in period 5 and group 14 or the carbon group of the periodic table. It liberates hydrogen from hot concentrated hydrochloric acid but concentrated sulfuric acid gives SnSO 4 and sulfur dioxide. The +2 state is the common and stable oxidation state of tin and lead but for other elements +4 state is common. Therefore, the properties of these elements differ widely from carbon and silicon. The elements Ge, Sn, and Pb have d and f electrons. All the elements contain an s 2p 2 valence shell electronic configuration. The chemistry and chemical properties of group 14 elements follow from their electronic configuration. The concentrate or black Sn is reduced with coke at 1200 to 1300 ☌ to produce Sn metal.The nonmagnetic tinstone is separated from magnetic wolframite and Fe 2O 3 by the magnetic separation technique.Sulfur and arsenic compounds are driven out. The washed ore roasted in a current of hot air.Light siliceous matter is largely removed. The major steps for extraction of metal are, The mineral cassiterite or tinstone contains only 1 to 5 percent of SnO 2, together with silica and wolframite. The isotope 119Sn (nuclear spin 1/2) is used for NMR studies and Mossbauer spectroscopy. Of these 120Sn, 118Sn and 116Sn are the most stable. In India, tinstone is found mostly in Bihar and Orissa. Malaysia, Russia, Bolivia, Indonesia, Peru Thailand, Brazil, and China are the major producer of the element Sn. Recovery or recycling of scrap tin is increasing rapidly due to the huge global demand. Tin scrap is also an important secondary source of metal. Small quantities of Sn are found in sulfides like stannite, cylindrite, franckeite, canfieldite, and teallite. Tin is slightly more abundant than germanium but it contains specific ores like cassiterite or tinstone (SnO 2).
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