The formula of sodium bicarbonate is NaHCO3. It's common name is Baking Soda.
In the laboratory, baking soda can be prepared by passing excess of carbon dioxide gas through the saturated solution of sodium carbonate. As a result, sodium bicarbonate is formed. Being sparingly soluble in water, it gets precipitated. The precipitate is separated, washed and dried without heating.
Na2CO3 + CO2 + H2O -----> 2NaHCO3
Here, NaHCO3 is a precipitate. It contains one atom of Sodium one atom of Hydrogen one atom of Carbon and three atoms of Oxygen.
Sodium Bicarbonate is also Sodium Hydrogen Carbonate.