All Boron compounds Borax decahydrate Name: Disodium tetraborate decahydrate CAS Number: 1303-96-4 EC Number: 215-540-4 Chemical formula: Na2B4O7 x 10H2O Synonyms: Sodium tetraborate decahydrate, borax, neobor Borax Pentahydrate Name: Disodium tetraborate pentahydrate CAS Number: 12179-04-3 EC Number: 215-540-4 Chemical formula: Na2B4O7 x 5H2O Synonyms: Disodium tetraborate pentahydrate, borax pentahydrate Boric acid Name: Boric acid CAS Number: 10043-35-3 EC Number: 233-139-2 Chemical formula: H3BO3 Synonyms: Orthoboric Acid, Boracic Acid, Boric acid