2-PYRIDINECARBOXYLIC ACID, 6-BROMO-

Borax is a Chinese herbal medicine, which also has many chemical properties. Borax, also known as sodium tetraborate, has a chemical formula of $Na_2B_4O_7 · 10H_2O $.
Borax is colorless and translucent crystals or white crystalline powder, odorless and salty. It can be slowly weathered in air and is easily soluble in water, and the aqueous solution is alkaline. This is because when borax is hydrolyzed, borate ions combine with hydrogen ions ionized by water, which increases the concentration of hydroxide ions in the solution and makes it alkaline.
Borax reacts with acid to form boric acid. If it reacts with hydrochloric acid, its chemical equation is: $Na_2B_4O_7 + 2HCl + 5H_2O = 4H_3BO_3 + 2NaCl $. Boric acid is weak in acidity, and this reaction occurs by following the principle of strong acid to weak acid.
Borax undergoes a series of changes when heated. At first, it loses its crystalline water, and then it is further decomposed by heat to produce products such as boron oxide. Borax also has fusibility. In the metallurgical industry, it is often used as a flux to reduce the melting point of metal oxides and assist in the smelting and welding of metals. When welding metals, borax can react with oxides on the metal surface to form fusible borates, which can remove oxides and make welding stronger.
In the printing and dyeing industry, borax can be used as a fire retardant for fabrics. The glassy substance formed by it at high temperature covers the surface of the fabric, blocking oxygen and heat, and achieving the effect of fire protection. In addition, in industrial fields such as enamel and ceramics, borax is also used to improve the heat resistance and chemical stability of products.
Although borax has a variety of chemical properties and a wide range of uses, its toxicity cannot be underestimated. Excessive intake of borax by the human body will endanger health, so it must be used with caution.

Borax is a kind of traditional Chinese medicine and is also used for external medicine. In many ancient medical texts, the records of borax used for gastric acid are quite rich, and its main uses are probably as follows:
First, clear away heat and reduce phlegm. Borax is cold in nature and has the power of clearing away heat. If cough or expectoration is caused by lung heat, and the sputum is sticky and difficult, borax can help clear away heat and reduce fire, dilute the sputum and make it easy to cough up. "Compendium of Materia Medica" contains: Borax "clears the heart and lungs from heat". If this heat evil causes lung diseases and causes coughing and other diseases, borax can play a role in clearing away heat and reducing phlegm.
Second, detoxify and prevent corrosion. Borax has the function of detoxification and antiseptic in sores, swelling and pain in the throat, sores in the mouth and tongue, etc. When the human body accumulates heat toxins, resulting in lesions in the mouth, throat and other parts, borax can be applied externally to the affected area, or gargle. For example, "Materia Medica Derivatives" says that it "contains pharyngeal fluid and treats swelling and pain in the throat". Borax can reduce local heat toxicity, relieve swelling and pain symptoms, and prevent further erosion of toxic evil at the same time. It has the effect of antiseptic and promotes healing of the affected area.
Third, reconcile medicinal properties. In some prescriptions, borax can be used as a reconciling medicine. Due to its relatively peaceful nature, it can coordinate the relationship between various medicines, make the medicinal effect of the whole prescription more harmonious, enhance the therapeutic effect of the prescription on diseases, and can ease the intensity of other medicines, making the drug effect more stable.
Fourth, digestion and accumulation. Borax helps the spleen and stomach transport. For stomach acid discomfort and epigastric fullness caused by diet stagnation, spleen and stomach loss, borax can promote food digestion, resolve stagnation, restore the normal transportation and transformation function of the spleen and stomach, thereby reducing the discomfort caused by excessive stomach acid.

To make boric acid, there can be various methods. First, borax and acid are prepared. Borax is sodium borate salt, which is combined with strong acids such as sulfuric acid and hydrochloric acid. It should be as follows: Borax encounters acid, borate ions combine with hydrogen ions in the acid to produce boric acid. The combination of borax and sulfuric acid forms boric acid and sodium sulfate, which can be obtained by crystallization or filtration to obtain pure boric acid.
Second, the decomposition of boric acid minerals. Some borate minerals, such as borosite, are roasted and leached by acid. First, the mineral is roasted to change its structure and increase the reactivity. Later, it is leached with sulfuric acid or hydrochloric acid, and the boron in the mineral is dissolved into boric acid. After removing impurities, concentrating and crystallizing, boric acid products are obtained. < Br >
Third, the method of hydrolysis of organic boron compounds. Organic borides, hydrolyzed under appropriate conditions, can also give boric acid. Such as some alkyl boron compounds, under the catalysis of acid or base, react with water, alkyl separation from boron, boron and water, boronic acid. This way needs to choose the right organic boron raw materials and hydrolysis conditions to achieve high efficiency and economy.
Fourth, sodium borohydride oxidation method. Sodium borohydride and oxidant should be combined to produce boric acid. Hydrogen peroxide is often used as an oxidant. At appropriate pH and temperature, boron in sodium borohydride is oxidized to form boric acid. This process needs to control the reaction conditions to ensure the stability of the reaction and the purity of the product.
All kinds of production methods have advantages and disadvantages. The actual application depends on the availability of raw materials, cost, product requirements, etc., and the appropriate method is selected.

I look at the market under the world, the price of materials and materials often varies according to time, place and quality. As for boric acid, its price in the market is not constant.
In the past, the price of boric acid fluctuated with the change of supply and demand. If there are many users, they need Yin, and their price may increase; if there are many producers, they supply enough, and their price may decrease. And the distance and proximity of the place, the difficulty of transportation, are also related to the price. Those who are far away and difficult to transport, their price is often higher than those who are conveniently transported near the place.
And the material is pure and miscellaneous, and the price is also very different. The price of pure is high, and the price of miscellaneous is low. This is also common sense. However, the current market conditions are ever-changing, and it is difficult to determine the range of its price. Basically speaking, the price of boric acid in the city, according to its quality, supply and demand, may be between a few yuan and tens of yuan per catty. This is only a rough estimate. If you want to know the exact price, you can only get it when you carefully examine the real-time news of the city and the sales and purchases of various companies.

Mercury is one of the hardware, and its properties are special. Acetic acid for storing mercury requires specific methods.
When storing mercury in acetic acid, the first choice for heavy utensils. When it is better to use porcelain or glass containers, because of its stable texture, it is not easy to chemically react with mercury and acetic acid, and can maintain the purity of mercury and the characteristics of acetic acid. If metal containers are used, mercury is prone to amalgamation with some metals, causing changes in the properties of mercury, and the metal may react with acetic acid, damaging the environment where mercury is stored.
The second consideration is the environment. The storage place should be cool and dry, protected from direct sunlight. The heat and light of sunlight can accelerate the volatilization of mercury and the chemical changes of acetic acid. Mercury is volatile. It evaporates faster at high temperatures. When it enters the air, it not only loses the amount of mercury, but also the mercury vapor is toxic and endangers human health. Acetic acid may decompose and polymerize under light and high temperatures, which affects the state of mercury storage.
Furthermore, sealing is crucial. Seal the container with a tight cover to prevent mercury volatilization and the mixing of external substances. External moisture, oxygen, etc., or interact with mercury and acetic acid. Moisture can cause the surface of mercury to oxidize, and acetic acid may be diluted or diluted in water, changing the chemical environment of mercury storage.
In addition, acetic acid in mercury storage should be kept away from fire sources and strong oxidants. Although mercury is chemically relatively stable, it may react violently when it encounters strong oxidants. Acetic acid is flammable, and it is easy to cause fire near the fire source, which endangers the safety of mercury storage.
Mercury is stored in acetic acid, and it is necessary to carefully select utensils, control the environment, strictly seal, and avoid dangerous substances in order to preserve the good state of mercury storage for later use.