Baking soda is white flour and baking soda is crystal.

1, baking soda (sodium bicarbonate) is white crystal or fine crystal of opaque monoclinic system. The specific gravity is 2. 15. Odorless, nontoxic, salty, soluble in water and slightly soluble in ethanol. It is soluble in 10 part of water at 25℃ and 12 part of water at about 18℃. Its aqueous solution is slightly alkaline due to hydrolysis, stable at room temperature, easily decomposed when heated, gradually decomposed above 50℃, completely lost carbon dioxide at 270℃, unchanged in dry air, and slowly deliquesced in humid air.

2. Sodium carbonate decahydrate refers to sodium carbonate hydrate containing 10 crystal water. Also known as edible noodle alkali, it is the main component of noodle alkali. It belongs to salt, not alkali. White monoclinic crystal. The density is1.44g/cm3. The melting point is 32.5 ~ 34.5℃. Heating to 33.5℃ to start dehydration. Soluble in water and hot water will release some heat. Insoluble in alcohol. Weathering rapidly in the air to form white powder.

The aqueous solution of surface alkali is weakly alkaline. React with acid to release carbon dioxide. Sodium carbonate and sodium sulfate are mixed with water in proportion, and the solution is cooled and crystallized at a lower temperature. Mainly used for pasta fermentation, but also for home washing and wool washing. Also known as sodium carbonate crystal, it is the crystalline form of Na2CO3. Heating will produce white sodium carbonate powder and water vapor.

: prepare

1, gas phase carbonization method:

The sodium carbonate solution is carbonized with carbon dioxide in sodium carbonate, and then separated and dried to obtain the finished product.

Na？ CO？ +CO？ (g)+H？ O==2NaHCO？

2, gas-solid phase carbonization method:

Put sodium carbonate in a reaction bed, mixing with water, blowing carbon dioxide from the lower part, carbonizing, drying, pulverizing and packaging to obtain the finished product.

Na？ CO？ +CO？ +H？ O→2NaHCO？

Supplement: Sodium bicarbonate can also be generated by the reaction of sodium carbonate with insufficient dilute hydrochloric acid.

Na？ CO？ +HCl→NaCl+NaHCO？

Hou Shi soda process: 2NaCl+2H2O+2CO? [Electrolysis] → 2 Sodium bicarbonate+chlorine =+H2 =

References:

Baidu encyclopedia sodium carbonate decahydrate (surface alkali)

References:

Sodium bicarbonate (baking soda generally refers to sodium bicarbonate)