Ca2B6O7, also known as Colemanite or natural borax, is a type of calcium borate salt. Its English name is Calcium hexaborate heptahydrate. It consists of two calcium atoms, six boron atoms, and seven oxygen atoms. Its atomic weight is around 249.949 g/mol.
Its molecular structure includes positive calcium ions (Ca2+) and negative borate ions (B6O7). This molecular structure reveals that both calcium and boron form ionic bonds with oxygen.
The physical properties of Ca2B6O7 include a solid state at room temperature with a pure white color. It has no distinctive smell and has a neutral pH.
In terms of chemical properties, Ca2B6O7 can react with metals, acids, non-metals, and salts. Some common chemical equations involving Ca2B6O7 include:
• Reaction with metals like Fe: Ca2B6O7 + 3Fe -> 2Ca + FeB6
• Reaction with acids like HCl: Ca2B6O7 + 2HCl -> 2CaCl2 + B6O7
• Reaction with non-metals like O2: Ca2B6O7 + O2 -> 2CaO + B6O7
• Reaction with salts like NaCl: Ca2B6O7 + 2NaCl -> 2CaCl2 + Na2B6O7
In the laboratory, Ca2B6O7 can be prepared from calcium and borax through a replacement reaction. Industrially, it is commonly produced from natural borax ore through a thermal decomposition process.