Sodium Carbonate is the disodium salt of carbonic acid with alkalinizing property. When dissolved in water, sodium carbonate forms carbonic acid and sodium hydroxide. As a strong base, sodium hydroxide neutralizes gastric acid thereby acting as an antacid. Sodium carbonate is an organic sodium salt and a carbonate salt. Sodium Carbonate is the disodium salt of carbonic acid with alkalinizing property. When dissolved in water, sodium carbonate forms carbonic acid and sodium hydroxide. As a strong base, sodium hydroxide neutralizes gastric acid thereby acting as an antacid.