Section 4: Copper And Tin In Metal Elements

SECTION 4 : COPPER AND TIN IN METAL ELEMENTS Copper Copper is a reddish-colored metal that occurs freely in nature and in the form of compounds. The most important copper ore is chalcopyrite (CuFeS2 , 34.5% Cu). Apart from that, there are several other copper compounds, such as cuprite (Cu2 O, 88.8% Cu), chalcosite (Cu2S, 79.8% Cu), and Malasite (Cu2(OH)2CO3 , 57.3% Cu. To obtain copper, foam flotation is first carried out to concentrate the copper ore. The next step is roasting the enriched ore, which is a reaction with air at high temperatures to convert the iron into its oxide and leaving the copper as sulfide. Next, the mixture of Cu2S and Fe3O4 and other ingredients is put into the furnace at a temperature of 1,100 °C. Because Cu2S does not dissolve in slag, Cu2S is flowed to another furnace via a jet of air to trigger a redox reaction. Finally, the liquid copper formed is then cooled and molded for further purification. Reaction: 6CuFeS2 (s) + 13O2 (g) 3Cu2 S(s) + 2Fe3O4 (s) + 9SO2 (g) CaCO3 (s) + Fe3O4 (s) + 2 SiO2 (s) S(l) + O2 (g) CO2 (g) + Cu2 slag 2Cu(l) + SO2 (g) The uses of copper include:         It is an excellent conductor of heat and electricity, so it is widely used in electrical equipment. As jewelry, a mixture of copper and gold. As a material for making coins. As a material for making other metals, such as brass (a mixture of copper and zinc), bronze (a mixture of copper and tin), monel, and alniko. CuSO4 in water is blue, widely used as a dye. A mixture of CuSO4 and Ca(OH)2 , called boderiux slurry , is widely used to kill insects or plant pests, prevent mold on vegetables and fruit. CuCl2 , used to remove sulfur content in oil processing. Cu(OH)2 which dissolves in NH4OH solution forms the cupric tetramine complex ion (known as Schweitser's solution), used to dissolve cellulose in the manufacture of rayon (artificial silk). Tin Tin is a silver-white metal, relatively soft, rust-resistant, and has a low melting point. Tin usually exists in two allotropic forms, namely white tin or the "metal" form which is stable at temperatures above 14 °C and gray tin or the "non-metal" form which is stable at temperatures below 13 °C. The main tin mine is tin(IV) oxide (SnO2 ), known as cassitente. I found tin mining in Bangka Island (Belitung). Tin is obtained by reducing SnO2 with carbon, according to the following reaction. SnO2 (s) + C(s) Sn(s) + CO2 (g) Tin is used to make packaging cans, such as for bread, milk, paint and fruit and to coat cans made of iron to prevent rust.Apart from that, it is also used to make mixed metals, for example bronze (a mixture of tin, copper and zinc) and solder (a mixture of tin and lead).