Chemical knowledge: the difference between soda, bicarbonate and bicarbonate
1. Soda
Soda is a transliteration of soda, and its chemical formula is Na2CO3. Scientific name is sodium carbonate, commonly known as soda, also known as soda or soda powder. With crystal water is called sodium carbonate hydrate.
Anhydrous sodium carbonate is white powder or fine particle, soluble in water, and the aqueous solution is alkaline. It has a strong hygroscopicity, can absorb water in the air and form a hard block.
Of the three sodas, sodium carbonate is the most widely used. It is a very important chemical product and an important raw material for glass, soap, textile, paper, leather and other industries. It is also used in metallurgical industry and purified water. It can also be used in the manufacture of other sodium compounds.
2. Baking soda
The chemical formula of baking soda is NaHCO3. Its scientific name is sodium bicarbonate, commonly known as baking soda.
Sodium bicarbonate is a white crystal, soluble in water, and the aqueous solution is weakly alkaline. In hot air, it can decompose slowly and release part of carbon dioxide; when heated to 270 ℃, the whole part will release carbon dioxide.
2NaHCO3==Na2CO3+H2O+CO2↑
There are many important uses in the production and life of baking soda. In the fire extinguisher, it is one of the raw materials for producing carbon dioxide; in the food industry, it is a main raw material for fermentation powder; in the manufacture of cool drinks, it is also a common raw material; in the medical treatment, it is a medicament for the treatment of excessive gastric acid.
3. Baking soda
Baking soda is the common name of sodium thiosulfate, also known as Haibo. It has five crystal water (Na2S2O3 · 5H2O), so it is also called sodium thiosulfate pentahydrate.
Sodium bicarbonate is a colorless and transparent crystal, which is easily soluble in water, and the aqueous solution is weakly alkaline. It weathered in dry air above 33 ℃ and lost crystal water. It is stable in neutral and alkaline solution and decomposes rapidly in acid solution.
Sodium bicarbonate has a strong complex ability and can form complex with silver bromide. It can be used as a fixer.
Baking soda also has strong reducibility, which can reduce chlorine and other substances.
It can also be used as dechlorination agent for cotton fabric after bleaching. Similarly, iodine stains on fabrics can be removed with it.
In addition, baking soda is also used for tanning leather, electroplating and extracting silver from ore.
In middle school, we mainly learn about soda and baking soda. Baking soda is generally not emphasized.
Tips: which soda is in soda water?
Soda water is the aqueous solution of sodium bicarbonate (bicarbonate), which contains weak alkali. It can be sterilized for external use in medicine. Drinking it can neutralize the acid-base balance in the human body and change the acid constitution. Most of the sodas sold on the market are synthetic carbonated drinks with carbon dioxide pressed into purified drinking water and sweeteners and spices added.
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