Borax (source code)
= Borax
<Borax> commonly denotes hydrated sodium tetraborate, conventionally written $\mathrm{Na_2B_4O_7\cdot10H_2O}$ for the decahydrate. Anhydrous and other hydrated sodium borates are distinct materials, so a mass-based chemical calculation must state the hydration form.<PubChem Compound database by National Center for Biotechnology Information>[Sodium tetraborate CID10219853: anhydrous formula and distinction from decahydrate borax]{ref}
The decahydrate's formal formula counts ten waters per tetraborate formula unit. Those waters contribute to its <molar mass> and change the amount of borate delivered by a weighed sample. In solution, acid–base equilibria and <pH> influence the distribution of boron-containing species; the crystalline formula does not require every dissolved boron unit to remain as one unchanged anion.
Back to article page
