Borax
Borax is a salt (ionic compound), a hydrated borate of sodium, with chemical formula Na2H20B4O17 often written Na2B4O7·10H2O. It is a colorless crystalline solid, that dissolves in water to make a basic solution. It is commonly available in powder or granular form, and has many industrial and household uses, including as a pesticide, as a metal soldering flux, as a component of glass, enamel, and pottery glazes, for tanning of skins and hides, for artificial aging of wood, as a preservative against wood fungus, and as a pharmaceutic alkalizer. In chemical laboratories, it is used as a buffering agent. The compound is often called sodium tetraborate decahydrate, but that name is not consistent with its structure. The anion is not tetraborate [B4O7]2− but tetrahydroxy tetraborate [B4O5(OH)4]2−, so the more correct formula should be Na2B4O5(OH)4·8H2O. Informally, the product is often called sodium borate decahydrate or just sodium borate. The terms tincal /ˈtɪŋkəl/ "tinkle" and tincar /ˈtɪŋkər/ "tinker" refer to native borax, historically mined from dry lake beds in various parts of Asia. (Wikipedia).
