Sodium carbonate, chemical name is soda/soda ash, chemical formula is Na2CO3. Usually white powder or fine-grained crystal, odorless, strong water absorption, easy to agglomerate. High temperature decomposition, easily soluble in water, the aqueous solution is alkaline. Although soda is also known as soda ash or caustic soda, it is a salt, not a base. It got its name because when soda is dissolved in water, the aqueous solution is alkaline.
Sodium carbonate is widely used in chemical, pharmaceutical, metallurgy, ceramics, rubber, machinery, printing and dyeing and other industries, and is a chemical raw material that we cannot obtain. In daily life, we can see sodium carbonate in the kitchen. It is generally used to wash oil stains, and it is also added when making steamed buns and buns.
Sodium bicarbonate, chemical name is baking soda, chemical formula is NaHCO3. Usually white crystalline powder, odorless, easily soluble in water. It decomposes slowly in moist or hot air, producing carbon dioxide. Easily decomposed by heat. It is completely decomposed when heated to 270 ° C, and the decomposition products are sodium carbonate, water and carbon dioxide.
Sodium bicarbonate is also widely used, which is basically the same as the industry where sodium carbonate is used, but not as much as sodium carbonate. In food processing, it is the most widely used filler, used in the production of biscuits, bread, etc., and is the generator of carbon dioxide in soft drinks; it can be mixed with alum to make alkaline baking powder, and it can also be mixed with soda ash to make civil lime alkali; Can be used as a butter preservative.
So what is the difference between sodium carbonate and sodium bicarbonate?
First, as can be seen from their chemical formulas, sodium carbonate is heavier. Under the same weight, sodium bicarbonate is heavier than sodium carbonate.
Secondly, from the appearance, sodium carbonate is mainly white powder, white and bright, and sodium bicarbonate is mainly white crystal, white and dark.
Third, sodium bicarbonate is unstable and will decompose in the air, but sodium bicarbonate just absorbs water and agglomerates. For the same weight of aqueous solution, sodium carbonate is more alkaline, while sodium bicarbonate is only weakly alkaline because sodium bicarbonate is hydrolyzed to form sodium carbonate.
Fourth, sodium carbonate and sodium bicarbonate react differently when heated. Sodium bicarbonate is unstable and easily decomposed when heated. Solid sodium bicarbonate decomposes immediately when heated; sodium carbonate melts and does not decompose when heated to 815 degrees Celsius, and has strong stability. It is not easy to decompose when heated.
Fifth, the chemical properties of sodium carbonate and sodium bicarbonate are different. Sodium carbonate aqueous solution is strongly alkaline and has certain corrosiveness. It can undergo metathesis reaction with acid and has strong stability, but it can also decompose to form sodium oxide at high temperature. and carbon dioxide; sodium bicarbonate, a weak base, is an absorbent antacid that quickly neutralizes stomach acid.
Sodium carbonate is an important organic chemical raw material, mainly used in the manufacture of chemical products such as glass, soap, paper, etc. It is also widely used in daily washing, acid neutralization and food processing. Sodium bicarbonate is an industrial chemical. Sodium carbonate and sodium bicarbonate should be distinguished when using. Especially in industrial use, the difference is still very large.
