Sodium Carbonate is a sodium salt of carbonic acid (soluble in water). Used as a food additive acting as an acidity regulator, anti-caking agent, raising agent and stabilizer, as a curing and pickling agent, a flavoring agent and a processing aid,
It is also a water conditioner, commonly used to adjust pH in water - from pools to spas to even drinking water.
As a medicine, because it neutralizes gastric acid, it acts an antacid.