Sodium bicarbonate, commonly known as "sodium bicarbonate", commonly known as "sodium bicarbonate", "soda powder", "heavy Cao", white fine crystals, has less solubility in water than sodium carbonate. It is an industrial chemical that may be toxic. It is easily decomposed by heat. Slow decomposition of solids in humid air above 50 ° C began to gradually decompose to form sodium carbonate, carbon dioxide and water, completely decomposed at 270 ° C. All changed to sodium carbonate at 100 °C. It is soluble in 10 parts of water at 25 ° C, soluble in 12 parts of water at about 18 ° C, and insoluble in ethanol. The non-stirred solution made of cold water has only a slightly alkaline reaction to the phenolphthalein test paper, and the base is increased by placing or raising the temperature. The pH of the freshly prepared 0.1 mol/L aqueous solution at 25 ° C was 8.3. . Sodium bicarbonate is an acid salt formed by neutralization of a strong base and a weak acid, and is weakly alkaline when dissolved in water. This feature makes it a leavening agent in the food making process. Sodium bicarbonate will remain sodium carbonate after its action, and too much use will give the finished product a basic taste. 
The reaction produced a variety of products (read)
is reacted with an acid 
with the reaction HCl: NaHCO3 + HCl ==== NaCl + H2O + CO2 ↑ 
and CH3COOH Reaction: NaHCO3 + CH3COOH ==== CH2COONa + H₂O + CO2 ↑ 
hydroxide Sodium reaction: NaHCO3 + NaOH ==== Na2CO3 + H2O 
reacts with calcium hydroxide: The dosage of sodium bicarbonate is divided into excess and small amount. 
A small amount: NaHCO3+ Ca(OH)2==== CaCO3↓+ NaOH + H2O 
excess: 2NaHCO3+ Ca(OH)2==== Na2CO3+ CaCO3↓+ 2H2O 
folding and salt reaction 
with CuSO4: formation of basic copper carbonate and sulfuric acid Sodium and water and carbon dioxide 
Folding hydrolysis 
with aluminum chloride: 3NaHCO3+ AlCl3====Al(OH)3↓+ 3CO2↑+ 3NaCl
Aldehydesulfate Al2(SO4)3+6NaHCO3==3Na2SO4+2Al(OH)3↓+6CO2↑ 
Folding Heating 
Thermal decomposition: 2NaHCO3==△== Na2CO3+ H2O + CO2↑ 
Folding ionization: sodium bicarbonate ionization equation NaHCO3 =Na+ + HCO3 -
Classification 
According to the nature classification: industrial grade baking soda and food grade baking soda, feed grade baking soda. The 
particle size 100 
content is 99.9-100.5. If it is asked to be more than 100, it is interpreted as experimental error. 
Production process
baking soda production The methods mainly include synthesis methods (high temperature alkali production), metathesis methods and natural alkali methods. 
1. Synthetic method: 
Synthetic method is also called soda ash method and soda ash carbonization method. At present, the domestic synthetic baking soda production equipment is basically constructed with the soda ash plant, so as to directly utilize the high-temperature soda ash from the calcination system of the process, accelerate the mother liquefaction alkali process, and provide qualified alkali liquor for subsequent operations. In order to ensure the excessive decomposition of NaHCO3 in the mother liquor, the phenomenon of NaHCO3 crystallization blockage during the transportation of lye is reduced, and the high material temperature is maintained throughout the operation. Therefore, the synthesis method is often referred to as a high-temperature alkali process. 
2. Double decomposition method: 
The metathesis method is a process for producing small sago using China's abundant raw salt and easy-to-purchase ammonium bicarbonate as main raw materials. Domestically, it mainly produces natural baking water as raw material for baking soda, also known as natural brine method. The bicarbonate is subjected to a metathesis reaction with agricultural ammonium hydrogencarbonate, and is directly precipitated from the solution by using a small solubility of ammonium hydrogencarbonate. The reaction principle is as follows: 
NaCl+NH4HCO3=NaHCO3+NH4Cl 
centrifugally separates the wet heavy alkali (aqueous NaHCO3), which can be shipped after washing with water, centrifugation, air drying, and fluidized bed cooling.
3, the natural alkali method: the natural alkali method is also called the natural alkali carbonization method, the natural alkali is mixed with the alkali in the alkali barrel, the slag is clarified, the clear liquid is filtered through the filter to obtain the alkali water, and the refined water is refined. The alkaline water is sent to the carbonation tower, and the carbonated reaction is carried out by using the washed carbon dioxide gas (the lime kiln gas is also available), the gas-liquid reaction is carried out to form sodium hydrogencarbonate crystal, and the precipitated sodium hydrogencarbonate crystal and the mother liquid are sent to the centrifugal separator together. Separation, while washing the mother liquor entrained between the crystals in the machine, the dehydrated filter cake (wet baking soda) contains about 8% water, and is sent to the hot air drying tube for air drying with hot air at a temperature of 130-140 °C. The dried baking soda is collected into a silo by a cyclone separator to obtain a product baking soda. 
Commonly used packaging 
Usually shipped in 25KG, 1000KG 
Uses
1, sodium bicarbonate can be directly used as a raw material for the pharmaceutical industry, for the treatment of hyperacidity. 
2, can also be used for film production, tanned leather, mineral processing, smelting, metal heat treatment, as well as for the fiber, rubber industry. 
3. Used as a detergent for wool, as well as for agricultural soaking. 
4. One of the most widely used bulking agents in the food industry for the production of biscuits, cakes, taro, bread, etc., is a carbon dioxide generating agent in soda drinks; 
5. It can be combined with alum as an alkaline baking powder, or Soda ash is compounded into civilian stone base; 
6. It can also be used as a butter preservative. 
7. Fire-fighting equipment is used to produce acid-base fire extinguishers and foam fire extinguishers. 
8. The rubber industry uses its role in uniform pores with alum and H porogens for rubber and sponge production. 
9. The metallurgical industry is used as a fluxing agent for casting steel ingots. 
10. The machinery industry is used as a forming aid for cast steel (turning sand) sand. 
11. The printing and dyeing industry is used as a fixing agent for dyeing printing, an acid-base buffering agent, and a finishing agent for fabric dyeing and finishing. Adding baking soda to the dyeing can prevent the yarn from producing a color.
13, can be directly used as raw materials for the pharmaceutical industry, wool detergent, foam fire extinguishing agent, bath agent, alkaline agent, leavening agent. Often used with ammonium bicarbonate to prepare a leavening agent for biscuits and cakes. 
14. A foaming agent (CO2) which can be formulated into a solid refreshing beverage with citric acid or tartaric acid. 
15. When used alone, it is strongly alkaline due to thermal decomposition. It will be yellow when used in bread and destroy vitamins in wheat. It is best to use it with acidic substances such as calcium hydrogen phosphate. 
16, can still be used for food blanching, to smell. Because it can raise the pH value, it can increase the water holding capacity of the protein, promote the softening of the cells of the food tissue, and promote the dissolution of the astringent component. 
It has a deodorizing effect on goat milk (dosage 10~20mg/kg). 
17. As acidity regulator and chemical leavening agent, China's regulations can be used for all kinds of foods that need to add leavening agent, and should be used according to the production needs. 
Practical baking soda (remarks)
different from soda ash (sodium carbonate) and baking soda (sodium bicarbonate) for industrial alkali. Baking soda is made by soaking carbon dioxide in a solution or crystal of soda ash. Therefore, baking soda is also called edible alkali (powdered) in some places. Baking soda is solid, round, white and soluble in water. 
The single salt is divided into: normal salt, acid salt and basic salt. The sodium hydrogencarbonate is an acid salt formed by neutralization of a strong base and a weak acid, and is weakly alkaline when dissolved in water. 
When mass production of steamed bread, fritters and other foods, the soda powder melt water is often mixed into the surface, and then decomposed into sodium carbonate, carbon dioxide and water after heat, carbon dioxide and water vapor overflow, which can cause the food to be more fluffy, and the sodium carbonate remains in the food. in. Adding excess soda powder to the taro can be tasted.