Sodium bicarbonate is a white, crystalline powder that is commonly used as a pH buffering agent, an electrolyte replenisher, systemic alkalizer and in topical cleansing solutions. Sodium bicarbonate is a salt that breaks down to form sodium and bicarbonate in water. This makes a solution alkaline. It's also called baking soda, bicarbonate of soda, or sodium hydrogen carbonate, white crystalline or powdery solid that is a source of carbon dioxide and so is used as an ingredient in baking powders, in effervescent salts and beverages. Sodium bicarbonate, commonly known as baking soda or bicarbonate of soda. It is a salt composed of a sodium cation and a bicarbonate anion. Sodium bicarbonate is a white solid that is crystalline, but often appears as a fine powder.