5-Fluoropyridine-3-carbaldehyde

"Tiangong Kaiwu" contains that silkworms are the leaders among silkworms. They have many functions and are crucial to people's livelihood and national plans.
Bearing the brunt of it, silk is a treasure in the textile industry. Its quality is soft and smooth, shiny and shiny, and the woven silk is beautiful. It not only shields the people from warmth, but also makes beautiful clothes for officials and dignitaries. And the silk trade, since the Han Dynasty, has been sold to foreign lands through the Silk Road, making China famous far and wide. It also earns huge wealth for the country and enriches the national treasury.
Furthermore, in addition to reeling silk, silkworm cocoons can be used as medicine to treat diseases. According to the "Compendium of Materia Medica" and other medical dictionaries, silkworm cocoons have a sweet taste and warm nature. They have the effect of nourishing yin and nourishing blood, removing wind and dehumidifying, and can treat symptoms such as futility and wind paralysis.
Silkworm sand should not be underestimated. It is rich in nutrients. After treatment, it is a high-quality fertilizer, which can fertilize the soil, nourish crops, fruits and vegetables, and improve crop yield. In traditional Chinese medicine, silkworm sand can also be used as medicine. It has the power of regulating qi and reducing dampness and relieving heat. It can solve the diseases of chest and abdomen ruffian, summer dampness and diarrhea.
In addition, silkworm breeding promotes the development of mulberry industry. Mulberry trees are widely planted, mulberry leaves are the food for silkworms, and mulberry skin can be used to make paper, mulberry can be used to make utensils and fuel, mulberry is delicious and has nourishing effects, and can be eaten raw or brewed. This industrial chain provides many livelihoods for the people and promotes local economic prosperity.
Mulberry silkworms play an extraordinary role in clothing, food, medicine, agriculture and many other fields. They have made outstanding contributions to the inheritance of Chinese civilization and economic development. They are really treasures of nature's gifts.

"Tiangong Kaiwu" has a saying: "All kinds of stones have it, and those in ochre, magnet, letter stone, and silver-containing ores are the top." Silver star stone is a kind of arsenic, and its texture is unique and its characteristics are extraordinary.
The color of silver star stone is often silver-white, shimmering with shimmering light, just like the embellishment of stars, hence the name. Its shape is mostly block-like, occasionally crystalline, and the surface is occasionally textured, or curved or straight, like a natural painting. Looking at it, it has a sense of warmth. Although it is not beautiful jade, it has a unique charm.
Its quality is brittle, and it is fragile to the touch. With a little external force, it becomes a powder. When placed under the light, a subtle reflection can be seen, as if silver sand is hidden in it. Smell it, there is a slightly pungent smell, although it is not strong, but if you smell it for a long time, you will feel uncomfortable.
Silver star stone is toxic, and it should not be close to food. If you touch it accidentally, you should clean your hands quickly. Calcined in the fire, its color turns red, and the smoke is billowing, and the smell becomes more and more pungent. This smoke is also highly toxic, and if inhaled, it will hurt the body.
Silver star stone has been used in the art of alchemy, but because of its toxicity, it needs to be used with caution. There are also doctors who use it in small amounts and go through multiple processing processes to remove its potency and use it to treat diseases. But those who are not proficient in pharmacology must not use it without authorization.

Mercury is strong and changeable. It is a metal, often in a liquid state, and the optical flow of silver is very flexible.
Looking at its physical properties, at room temperature, it is only liquid, different from the solid state of all metals. Its density is quite large, and it touches the sinking. And it has good conductivity, which can be used in many electrical instruments.
As for chemical properties, mercury is abnormally active. Although it is relatively stable at room temperature, it is easy to combine with oxygen to form mercury oxide when heated. When it encounters sulfur, the two rapidly phase and synthesize mercury sulfide. This reaction is often used as a treatment for mercury leakage.
Mercury is in acids, and when it encounters strongly oxidizing acids, such as nitric acid, it will chemically react. Mercury is oxidized to form mercury salts, and gases escape. However, in hydrochloric acid and dilute sulfuric acid, mercury is relatively stable and reacts less.
Mercury can form alloys with a variety of metals, called amalgams. The formation of this amalgam also shows the unique chemical properties of mercury. If mixed with sodium, it can form sodium amalgams, which are widely used in organic synthesis and other fields.
Mercury compounds have various forms and properties. Mercury oxide is easily decomposed when heated, releasing oxygen. Mercury chloride is highly toxic and has a certain solubility in water. Mercury sulfide is brightly colored, such as cinnabar, and its chemical properties are relatively stable.
The chemical properties of mercury are both active and unique, and it is widely used in the field of chemistry. However, its toxicity also needs to be treated with caution by the world, and it should be used reasonably and properly to ensure both security and benefits.

There are various methods for making acetonitrile in ancient times. One is obtained by dehydrating ammonia acetate. Take ammonia acetate, place it in a kettle, heat it, dehydrate it, and then obtain acetonitrile. This is one of the ancient methods, but the process requires fine temperature control, otherwise it will be difficult to achieve.
Second, ethanol and ammonia are combined through the action of a catalyst. First prepare ethanol and ammonia, so that the two can react under the environment of the catalyst in an appropriate proportion. Among them, the choice of catalyst is very important, which is related to the rate and effectiveness of the reaction. And the temperature and pressure of the reaction also need to be precisely regulated to make the two effectively combine to obtain acetonitrile. < Br >
In addition, it can be obtained by catalytic hydrogenation of acrylonitrile. Acrylonitrile is guided by a catalyst, combines with hydrogen, undergoes a hydrogenation reaction, and is converted into acetonitrile. In this process, the activity and selectivity of the catalyst are the key, which is related to the purity and yield of the product.
Another method is to react methanol with hydrocyanic acid. Make methanol and hydrocyanic acid meet under suitable conditions, and through a series of reactions, acetonitrile is finally obtained. This approach requires attention to the proportion of reactants, the control of reaction conditions, and hydrocyanic acid is highly toxic. When operating, be extremely cautious to prevent accidents.
All these methods have advantages and disadvantages. It may require high temperature, or rely on catalysts, or involve highly toxic substances. However, they are all gathered by the wisdom of predecessors, and in the process of chemical engineering, they are the essential methods for making acetonitrile.

There is a commercial market today, what is the price of eels? Eels, the genus of aquariums, taste delicious and nutritious, and people like to eat more, so they have their price in the city.
Looking at cities, the price of eels often varies from time to time, from quality to quality, and from situation to situation. Generally speaking, the price of ordinary eels in the city is between 20 and 50 yuan per catty. If the eels are strong, the meat is fresh and tender, and they are newly caught in the current season, the price may be slightly higher, up to more than 50 yuan per catty. If the quality of eels is slightly inferior, or not freshly caught, the price may be lower than 20 yuan.
In addition, the size of the city and the distance of the land also have an impact on the price of eels. In most cities, there are many people, and there are many seekers, so the price of eel may be higher; in remote places, the yield of eel is less, and when transported to the city, the cost increases and the price is not cheap. However, there are also small rural cities, where the eel production is quite abundant, the supply is sufficient, and the price is relatively flat, about twenty yuan per catty.
And the cold and summer of the time are also related to the price of eel. In the hot summer season, the eel is active, it is easy to catch, and the supply of the city is large, and the price often flattens; in the cold winter, the eel is hidden, and it is difficult to catch. The market quantity is small, and the price may rise.
To sum up, the price of eel in the market is roughly between 20 and 50 yuan per catty, but due to various reasons, the price also changes from time to time.