Sodium bicarbonate (English: sodium bicarbonate, IUPAC name: sodium hydrogen carbonate, baking soda) is an inorganic compound, the chemical formula is NaHCO3, commonly known as baking soda, soda powder, heavy cassia, baking soda, etc., it is a white fine crystal, in water The solubility is less than that of sodium carbonate, and it is weakly alkaline.

Chemical Properties

Sodium bicarbonate is an acid salt formed by neutralizing a strong base and a weak acid. It is weakly alkaline when dissolved in water.
It begins to decompose gradually above 127°C to form sodium carbonate, carbon dioxide and water, and completely decomposes at 270°C.
2 NaHCO3 → Na2CO3 + H2O + CO2↑

This characteristic is often used as a leavening agent in the process of food production.
Sodium bicarbonate can react with acid to form the corresponding sodium salt:
NaHCO3 + CH3COOH → CH3COONa + H2O + CO2↑
NaHCO3 + HCl → NaCl + H2O + CO2↑

Sodium bicarbonate solution can react with magnesium:
4 Mg + 8NaHCO3 + 4 H2O → 3MgCO3 Mg(OH)2 3H2O + 4 Na2CO3 + 4 H2↑ + CO2↑

Method Of Manufacture

The most common preparation method of sodium bicarbonate is to pass carbon dioxide into a sodium carbonate solution and crystallize to obtain:
Na2CO3 + CO2 + H2O → 2 NaHCO3

Another method is to inject excess carbon dioxide into the saturated brine while electrolyzing it.

2 NaCl + 2 H2O + 2 CO2 - power on → 2 NaHCO3 + Cl2↑ + H2↑

In this reaction, electrolysis produces sodium bicarbonate, chlorine, and hydrogen.

The industrial production method of sodium bicarbonate is Hou's soda production method: NaCl+NH3·H2O+CO2==NaHCO3+NH4Cl passes carbon dioxide into the saturated brine filled with ammonia gas, the solubility of sodium bicarbonate is low, and it will precipitate soon down

Laboratory Use

Sodium bicarbonate can be used as an analytical reagent and is also used in inorganic synthesis.  It can be used to prepare sodium carbonate-sodium bicarbonate buffer solution. When adding a small amount of acid or alkali, it can keep the hydrogen ion concentration from changing significantly, and keep the pH value of the system relatively stable.

Industrial Use

Sodium bicarbonate can be used in the production of acid-base fire extinguishers and foam fire extinguishers. In the rubber industry, sodium bicarbonate can be used in the production of rubber and sponge. In the metallurgical industry, sodium bicarbonate can be used as a flux for casting steel ingots. In the machinery industry, sodium bicarbonate can be used as a molding aid for cast steel (foundation) sand molds. In the printing and dyeing industry, sodium bicarbonate can be used as a color-fixing agent for dyeing and printing, an acid-base buffer, and a post-treatment agent for fabric dyeing and finishing; adding baking soda to the dyeing can prevent yarn bobbins from producing color patterns, and can also be used for washing wool agent.

Food Processing Purposes

In food processing, sodium bicarbonate is the most widely used loosening agent, used to produce biscuits, bread, etc., but sodium carbonate will remain after the action, too much use will cause the food to be too alkaline and cause the flavor to deteriorate. The color is yellowish brown. It is a generator of carbon dioxide in soda drinks; it can be compounded with alum to make alkaline fermentation powder, and it can also be compounded with soda ash to make civil lime; it can also be used as a butter preservative. It can be used as a color-protecting agent for fruits and vegetables in vegetable processing. When washing fruits and vegetables, adding about 0.1%~0.2% sodium bicarbonate can stabilize the green color. When sodium bicarbonate is used as a treatment agent for fruits and vegetables, the pH value of fruits and vegetables can be increased by boiling and bleaching of fruits and vegetables, the water holding capacity of protein can be improved, the softening of food tissue cells can be promoted, and the astringent components can be dissolved. In addition, it has the effect of removing mutton from goat milk, and the dosage is 0.001%~0.002%.

Agricultural and animal husbandry purposes

Sodium bicarbonate can be used for soaking seeds in agriculture, and can also make up for the lack of lysine content in the feed. Sodium bicarbonate can be dissolved in a small amount of water or mixed into the concentrate to feed cattle (add in appropriate amount), which can promote the growth of cattle. It can also significantly increase the milk production of dairy cows.

Medical Use

Sodium bicarbonate can be used as a pharmaceutical raw material to treat hyperacidity, metabolic acidosis, and to alkalize urine to prevent uric acid kidney stones. It can also reduce the nephrotoxicity of sulfonamides, prevent hemoglobin from depositing in the renal tubules during acute hemolysis, and treat symptoms caused by hyperacidity; intravenous infusion has non-specific effects on barbiturates, salicylic acid drugs, and methanol poisoning. therapeutic effect. However, it is contraindicated for gastric lavage when swallowing strong acidosis, and when a large amount of injection, renal insufficiency, or long-term application may occur, arrhythmia, muscle spasm, pain, abnormal fatigue and weakness, slow breathing, odor in the mouth, frequent urination, urgency, Persistent headache, loss of appetite, nausea, vomiting, etc.