2-PYRIDINECARBOXYLIC ACID, 3-HYDROXY-

The carboxyl group is very important in organic chemistry. Its main uses are about three.
One is related to acidity. The carboxyl group can ionize hydrogen ions, so the compound containing the carboxyl group is acidic. Such as the common acetic acid, because of its carboxyl group, it can partially ionize in water, showing the properties of acids, and can neutralize with bases. "Zhou Li · Kaogong Ji" said: "The surface of the test is used to determine the five materials, so as to distinguish the people." Although this is said to make utensils, in chemistry, the identification of the acidity of carboxyl groups is also the key to understanding the properties of substances and preparing compounds. It can be used for acid-base neutralization experiments and industrial production to prepare corresponding salts. < Br >
Second, participate in the esterification reaction. Carboxyl groups can esterify with alcohols under acid catalysis and other conditions to form esters. This reaction is widely used in fragrances, drugs and many other fields. Esters often have a special aroma, such as the aroma of fruits, which is mostly derived from the ester components. Just as "Tiangong Kaiwu" said: "The silk, hemp, fur and brown in the world have quality, so that the special color can be used." The esterification reaction endows the compound with different properties. In the fragrance industry, a variety of fragrant fragrances can be produced through this reaction. In drug synthesis, drugs with ester structures may have better solubility and stability.
Third, it has a significant role in metabolism in organisms. The synthesis and metabolism of many biological macromolecules, such as proteins, nucleic acids, etc., are related to carboxyl groups. Amino acids are the basic building blocks of proteins, with amino groups at one end and carboxyl groups at the other end. Amino acids dehydrate and condensate with carboxyl groups to form peptide bonds, and then form proteins. This process is similar to the creation process described in "Tiangong Kaiwu", which is interlinked and indispensable. The metabolic pathways in organisms are complex and delicate, and carboxyl groups participate in various biochemical reactions here to maintain the normal operation of life.
Carboxyl groups have a wide range of uses and play a key role in many fields such as chemistry, industry, biology, etc., and have far-reaching impact on human life and scientific research.

Boron and its compounds were not as well understood in ancient times as they are in modern times, but they still have their unique properties worth exploring. Although borane was not accurately recorded at that time, it is speculated by its modern understanding that there should be something special. Borax, which the ancients may have come into contact with, is water-soluble, soluble in water, and can react with acids and bases. When heated, borax will melt, and its properties will change accordingly.
Boric acid, in the shape of a white powder, is its appearance characteristic. Boric acid is slightly acidic, and this chemical property makes it react with other substances under certain circumstances. It also has a certain solubility and is soluble in water. Although the solubility is not very high, it can form a boric acid solution in water. In terms of physical state, it is a solid under normal conditions and has relatively good stability, but when conditions such as heat change, it may change its properties.
In ancient times, although the understanding of boron and its compounds was limited to superficial observation and could not go deep into the microstructure and precise chemical principles, these external physical properties were already used by the ancients. For example, the melting properties of borax play a role in simple metallurgy, glass manufacturing and other processes, and the solubility and weak acidity of boric acid may have traces in some simple medicines, dyeing, etc. With the passage of time and technological progress, more properties of boron and its compounds have been discovered and utilized, and its importance has become increasingly prominent.

Borax has a peaceful and salty taste. It is a natural mineral, mostly found in salt lakes and dry river beds. Its chemical properties are unique and useful in many fields.
The first chemical property of borax is its alkalinity. Borax can be hydrolyzed in water to produce hydroxide ions, causing the solution to be alkaline. This property makes it a neutralizer in some chemical reactions and regulates the pH of the reaction system.
Second, borax has coordination properties. Boron atoms in the borax structure have empty orbitals and can form coordination bonds with molecules or ions with lone pairs of electrons. In this way, borax can complex with many metal ions to form stable complexes. This property is widely used in metallurgy, electroplating and other industries. It can help separate and purify metals and improve the properties of metal surfaces.
Furthermore, borax has good thermal stability. When heated, borax will gradually lose its crystalline water, and at higher temperatures, it can also maintain its own relatively stable structure. This property makes borax play an important role in ceramics and glass manufacturing processes. It can be used as a flux to reduce the melting point of raw materials, promote the formation of glass and ceramics, and improve the heat resistance and chemical stability of products.
In addition, borax can react with acids in aqueous solutions. To form boric acid and other products, this reaction is often used to prepare boric acid. Boric acid is used in medicine, cosmetics, preservatives and other fields.
The chemical properties of borax are diverse, including alkalinity, coordination, thermal stability, and acid reactivity, making it indispensable in many industries such as chemical engineering, metallurgy, and materials. It is like a silent behind-the-scenes hero who promotes the development and progress of many fields.

There are three ways to make citric acid. First, take the real citrus, twist the cloth to get the juice, put it in a kettle, fry it over low heat, and wait for it to concentrate to get citric acid. Second, mix tartaric acid with lime water, wait for it to react, form calcium tartrate precipitation, filter it out, and then treat it with sulfuric acid, so that calcium and sulfuric acid are combined into calcium sulfate precipitation, and then remove the remaining liquid as a citric acid solution, which can be obtained by evaporation and concentration. Third, use sugar as raw material, inoculate Aspergillus niger, ferment it in a suitable warm and humid environment, and then through a series of separation and purification techniques, citric acid can also be obtained. The three methods have their own advantages and disadvantages. The first method directly extracts the juice and concentrates it, which is simple and easy to implement, but the yield may not be high. The second method is chemically reacted, and the process is slightly complicated, but the product is relatively pure. The last method is fermented and can be mass-produced. However, it is necessary to control the fermentation conditions.

I look at your question, but I am inquiring about the price range of carboxyl groups in the market. Carboxyl groups, which are not sold independently, are actually a specific functional group in chemical substances.
Carboxyl groups are commonly found in many organic acid compounds. To know their relevant prices, it depends on the specific compounds containing carboxyl groups. For example, acetic acid is a common carboxyl-containing organic acid. Its price varies in the market according to purity, packaging, batch size, etc. General industrial-grade acetic acid, when purchased in bulk, the price per ton may be between hundreds and thousands of yuan.
Another example is benzoic acid, which also contains carboxyl groups. As an important organic synthesis raw material and preservative, in the market, ordinary industrial benzoic acid, the price per kilogram may range from a few to tens of yuan. If it is a high-purity, special-purpose benzoic acid product, the price will be higher.
Another example is citric acid, which is widely used in food, beverage and other industries, and its price is also affected by market supply and demand, quality and other factors. Ordinary food-grade citric acid, the price per kilogram is roughly between a few yuan and a dozen yuan.
In short, the carboxyl group itself is difficult to directly negotiate the price, depending on the specific compound it is located in, and the price of each compound fluctuates due to various factors, it is difficult to give a unified price range.