pyridine, 3-chloro-2,4,5,6-tetrafluoro-

"Tiangong Kaiwu" cloud: The nature of water is soft and good flow. It is also in things. When it encounters square, it is square, and when it encounters circle, it is round. As for the water of the four seas of 2, 4, 5, and 6, its physical properties also have many characteristics.
The first word is its density. The density of water is about 1 gram/cubic centimeter, but it varies slightly at different temperatures. The water of the four seas has different densities due to differences in region, depth, and salinity. For example, seawater has a higher salinity, and the density is often greater than that of fresh water. The higher the salinity, the greater the density. And when the temperature decreases, the density of water tends to increase. When it reaches 4 ° C, the density is the maximum, and then it continues to decrease with the temperature, and the density gradually decreases.
The second time talks about its solubility Water is a good solvent, and the water of the four seas dissolves many substances, such as salts and gases. Seawater is rich in salts such as sodium chloride and magnesium chloride, which give seawater a salty taste. And water can dissolve a certain amount of oxygen, carbon dioxide and other gases, which is essential for the survival of marine life. The amount of dissolved gas in water is related to temperature and pressure. When the temperature increases, the solubility of the gas decreases; when the pressure increases, the solubility of the gas increases.
Furthermore, the specific heat capacity of water is large. The water of the four seas has significant specific heat capacity characteristics due to the huge water body. When absorbing or releasing a lot of heat, the water temperature changes relatively slowly. This property allows the ocean to adjust the climate. It absorbs heat in summer and slows down the rise in temperature; it releases heat in winter to alleviate the sudden drop in temperature. < Br >
Also on its surface tension. The surface of water is like an elastic film with surface tension. The water of the four seas, when it is calm, this surface tension is reflected. Small objects can float on the water surface, and insects can walk on the water surface, all due to the work of surface tension.
In addition, the boiling and freezing points of water are also important physical properties. Under standard atmospheric pressure, the boiling point of water is 100 ° C, and the freezing point is 0 ° C. Water of the four seas, due to factors such as pressure and salinity, will change between the boiling and freezing points. Due to the existence of salinity, the freezing point of seawater is lower than 0 ° C and the boiling point is higher than 100 ° C.

"Water is the source of all things, and its properties are changeable, and it shows different states in different environments. As for halogen, if 2, 4, 5, and 6 are in the same direction, its chemical properties are also interesting."
Halogen, which converges in the four streams of 2, 4, 5, and 6, has several properties. First and foremost, halogen is soluble. Many substances are soluble in halogen, just like salt in water, which is its ability to dissolve other substances. Moreover, the boiling point and freezing point of halogen are different from ordinary water, and the four streams meet, which makes its physical properties different, which in turn affects its chemical performance.
Furthermore, halogen is reactive. Due to the complexity of its components, it often interacts with other substances, causing them to react wonderfully. Or when it meets with metals, it can cause metal corrosion, or it can react with certain compounds to give birth to new substances.
Repeat, halogen is oxidizing or reducing. Depending on the ingredients it contains, under specific conditions, it may be oxidizing and take away electrons from other substances; or it is reducing, giving electrons to other substances to promote the occurrence of chemical reactions.
In addition, the pH of halogen also needs to be considered. The four streams converge, or make the halogen acidic or alkaline. The acid-base property has a huge impact on the objects in contact with it, and can change the route and rate.
To sum up, the halogen of the four streams of 2, 4, 5, and 6 has various chemical properties, such as solubility, reactivity, redox, and pH. These are all important characteristics, and have a significant impact in many fields such as chemical industry and metallurgy.

"Tiangong Kaiwu" is a scientific and technological masterpiece written by Song Yingxing in the Ming Dynasty. There is no direct mention of specific chemicals such as "mercury-2,4,5,6-tetrachlorobiphenyl", because the chemical science in the book era has not yet developed to the extent that such complex compounds can be clearly recognized.
However, the book has a lot of explanations on the uses of many substances. From the perspective of ancient cognition, it is inferred that mercury (mercury) has a wide range of uses. Mercury is fluid and has a metallic luster, and was often used in alchemy in ancient times. Although this concept is not correct in the eyes of modern science, it was an important raw material for alchemy activities at that time.
In addition, mercury also had some applications in ancient medicine. Traditional Chinese medicine books have recorded the use of mercury and mercury compounds as medicine, such as cinnabar (mercury sulfide), which is believed to have calming effects, but due to the toxicity of mercury, it is now used with extreme caution.
As for 2,4,5,6-tetrachlorobiphenyl, which is an organic pollutant produced by modern industry, there is no such substance when "Tiangong Kaizhi" was written, and there is no relevant use record. However, from a modern perspective, 2,4,5,6-tetrachlorobiphenyl was used in industrial production as an insulating oil, plasticizer, etc. Due to its stable chemical properties, it was later found to be extremely harmful to the environment and biology, and has been banned in many countries.

"Tiangong Kaiwu" states that mercury, that is, mercury, wants to make four mercury to its utensils, and the methods are as follows:
First, cinnabar upgrading method. Cinnabar is an important ore of mercury, and cinnabar is placed in a special furnace tripod, sealed and heated. Cinnabar is decomposed by heat, mercury is turned into steam and rises, and condensed on the upper part of the furnace tripod when cooled. Pure mercury can be obtained by collecting. This is a commonly used method for mercury refining in ancient methods. Because cinnabar has a high mercury content and is easy to obtain and process.
Second, the replacement method of bile alum and iron. First take bile alum (copper sulfate crystal) and dissolve it in water to obtain a blue solution. Then put the iron block into it, the activity of iron is higher than that of copper, and a replacement reaction occurs. Iron replaces the copper in copper sulfate, and ferrous sulfate is formed in the solution. At the same time, bile alum also contains trace amounts of mercury, which can be precipitated through a series of reactions and treatments. This process requires attention to the reaction conditions and subsequent separation and purification to obtain relatively pure mercury.
Third, other ore refining methods. There are still many mercury-containing ores in nature, such as mercurite. For such ores, it is necessary to improve their reactivity according to their characteristics, or by physical treatment such as crushing and grinding. After that, the mercury is separated from the ore by chemical means such as roasting and leaching, and then the mercury is collected by distillation, condensation and other steps. However, these methods are often complicated due to the complex composition of the ore, and the processing process is more complicated, requiring fine operation and control.

Good, if you want to talk about mercury and the four oceans of two, four, five, and six, you should pay attention to all things during storage and transportation, and listen to me in detail.
Mercury is also highly toxic. It is liquid at room temperature and volatile, so when storing and transporting, it is the first way to seal it. It must be kept in a strong and airtight container to prevent the leakage and volatilization of mercury. If the container is slightly damaged, mercury will escape from the outside, which will not only pollute the environment, but also cause great harm to humans and animals.
As for the four oceans referred to in two, four, five, and six, although it is not specified what it is, when transporting it, it is also necessary to check its phase with mercury. If the two encounter a biochemical reaction that causes danger, they must be transported separately and must not be mixed in one place.
Store in a dry, cool and well-ventilated place. Mercury is afraid of heat, and high temperature can promote its volatilization to accelerate, so it should not be placed in direct sunlight or warm places. And good ventilation can reduce the accumulation of mercury vapor in the air and reduce the risk of poisoning.
During transportation, steady and slow travel is also the key. Avoid bumps and vibrations to prevent damage to the container. The escort should be professional and familiar with the characteristics of mercury and emergency measures. In case of emergencies, such as mercury leakage, sulfur powder can be quickly sprinkled on it to combine mercury with it and reduce its toxicity and volatility.
Furthermore, the storage and transportation of mercury should be in accordance with relevant laws and regulations. Documentary records must be detailed, from the source to the whereabouts, and should be clearly traceable. In this way, mercury can be stored and transported without harm and safely.