Borate

Borates in chemistry are chemical compounds containing boron bonded to three oxygen atoms written as B(OR)³. In B(OR)⁴− anions, this number increases to four.

The borate ion is BO₃³−. it forms salts with metallic elements. Boron found in nature is commonly as a borate mineral. Boron is also found combined with silicate to form complex borosilicate minerals such as the tourmalines.

Borate exists in many forms. In acid and near-neutral conditions, it is boric acid, commonly written as H₃BO₃ but more correctly B(OH)₃. The pKa of boric acid is 9.14 at 25C. Boric acid does not dissociate in aqueous solution, but is acidic due to its interaction with water molecules, forming tetrahydroxyborate.