Calcium alginate (CAS Reg. No. 9005–35–0) is the calcium salt of alginic acid, a natural polyuronide

constituent of certain brown algae. Calcium alginate is prepared by the neutralization of purified alginic acid with appropriate pH control agents, or from sodium alginate by metathesis with appropriate calcium salts.

Molecular formula：[(C6H7O6)2Ca]n