ABSTRACT
Most commercial sources of tin are placer deposits of cassiterite, SnO2, unevenly distributed in the Far East and Africa and deep mined deposits in Bolivia. Tin is kinetically stable in unpolluted air because the freshly exposed metal surface immediately acquires a tenacious passive film based on a derivative of SnO2. Tin is applied as a corrosion-resistant coating to the inner surfaces of steel food cans, taking advantage of the polarity reversal of iron and tin in deaerated aqueous solutions of organic acids such as fruit juices that form complex ions with tin. Pure tin is chemically remarkably stable and inert with respect to moisture. Before the development of ion exchange resins the only means of producing the highest purity water was by distillation using a still entirely made of tin. Pewter is essentially tin alloyed with antimony or copper to harden it.
