Tin is a widely sought metal and is used in hundreds of industrial processes throughout the world.
In the form of tinplate, it is used as a protective coating for copper vessels, various metals used in the manufacture of tin cans, and similar articles. Tin is important in the production of the common alloys bronz e, solder, and type metal. Tin forms stannic acid, H2SnO4, when heated in air or oxygen at high temperatures. It dissolves in hydrochloric acid to form stannous chloride, SnCl2, and in aqua regia to form stannic chloride, SnCl4, and it reacts with sodium hydroxide solution to form sodium stannite and hydrogen gas. Stannous sulfide, SnS, is yielded as a dark brown precipitate by the action of hydrogen sulfide on a solution of stannous chloride.