Thiophene, 2,3,4,5-tetrachloro-

The physical properties of 2,3,4,5-tetrachloro-ethane are as follows:
This compound is a colorless liquid at room temperature and pressure, and smells like chloroform. Its density is greater than that of water, about 1.60 g/cm ³, so if it is mixed with water, it will sink in the lower layer of water. Its boiling point is between 146 and 147 ° C. At this temperature, the compound changes from liquid to gaseous. The melting point is -43 ° C. When the temperature drops below the melting point, the compound will solidify from liquid to solid.
2,3,4,5-tetrachloro-ethane is slightly soluble in water, but it can be miscible with most organic solvents, such as ethanol, ether, acetone, etc. This is because of the similar miscibility, and its molecular structure is similar to that of organic solvents. And this substance has a certain degree of volatility and can slowly evaporate in air to form vapor.
Furthermore, its refractive index is about 1.491. When light passes through this substance, it will be refracted at a specific angle. This property is used in the fields of optics and analytical chemistry, or can be used for the identification and purity detection of substances.
Its surface tension also has a certain value, which affects the contact state of liquid and solid surfaces and the behavior at different interfaces. In addition, the viscosity of 2,3,4,5-tetrachloro-ethane is moderate, and the internal friction during the flow process is neither too large to hinder the flow, nor too small to be too dilute. This property is of great significance in some industrial processes involving fluid transportation and mixing.

The tetrahalide of two, three, four, and five has its own unique chemical properties.
The dihalide often has a certain stability. In common reactions, it can participate in nucleophilic substitution reactions. The capped halogen atom has a certain electronegativity, which can make the carbon atoms connected to it partially positive, so it is easy to be attacked by nucleophilic reagents. For example, the reaction of dihalogenated alkanes with sodium alcohol can form ether compounds. And under certain conditions, dihalides can also undergo elimination reactions, dehalide hydrogen, and form unsaturated bonds.
Trihalides, whose chemical activity is often higher than that of dihalides. Due to the influence of multiple halogen atoms, the polarity of the molecule is enhanced, making it easier to react with nucleophilic reagents. And under the action of specific catalysts, trihalides can undergo a series of complex rearrangement reactions to form compounds with more special structures.
tetrahalides, some tetrahalides have high stability, but some have special reactivity. Taking tetrahalomethane as an example, its chemical properties are relatively stable and it is difficult to react with general reagents. However, when high temperature, light or a specific catalyst exists, tetrahalomethane can dissociate halogen atoms, which in turn triggers a series of free radical reactions. The tetrahalogenated ethylene compounds, due to the conjugation effect of double bonds and halogen atoms, have different reactivity from ordinary olefins, and can undergo unique addition reactions.
Pentahalides are relatively rare, and often have strong oxidizing properties due to their high valence states. In chemical reactions, pentahalides can participate in the reaction as oxidants to oxidize other substances, reduce the valence state of their own halogen atoms, and generate corresponding reduction products.
In short, di-, tri-, tetra-, and five-tetrahalides have different chemical properties due to differences in the number of halogen atoms and molecular structures, and play unique roles in organic synthesis and many chemical fields.

Lead and mercury, two, three, four, five - tetrahalogen - what is its main use? This is related to the nature and use of things, and it is also related in "Tiangong Kaiwu".
Lead and mercury have long been known by the ancients. Lead is blue and gray in color, soft and heavy in quality, and stable in nature. In ancient times, it was widely used. First, the use of casting tools. Lead has good casting properties and can be cast into various utensils. Such as lead tripods, lead pots, etc., although not more precious than bronze, they are also practical in the folk and can be used as containers. Second, in alchemy, lead is also an important thing. The ancients believed that alchemy could lead to longevity, and lead and mercury were often used as raw materials for alchemy. With its changing nature, they wanted to refine miraculous pills.
Mercury is liquid at room temperature, with silver light flowing, and was called "mercury" in ancient times. Its unique nature and many uses. In alchemy, mercury and lead are compatible, participating in the complex process of alchemy. The ancients believed that mercury has strange properties, and lead and other substances can be changed to form "immortal medicines". Furthermore, mercury is also used in medical treatment. Although mercury is known to be toxic today, ancient physicians used it for the treatment of certain diseases due to its special properties, but the dosage and usage should be cautious.
As for two, three, four, five - tetrahalogen, halogen is known as the halogen element. However, it did not have the chemical understanding of today in ancient times, but in real life, or involved with halogen-containing things. Halogen salt can be used to season and pickle food, so that the food can be preserved for a long time and has a unique flavor. In some processes, halogen-related things may also participate in the change and production of substances. However, due to the limited understanding in ancient times, it is not as clear and clear as it is today. However, its use is also apparent in life crafts and other aspects.

To make tetrachloroethane, the method is as follows:
Take two, three, four, and five raw materials, prepare corresponding utensils, choose a clean place, and operate according to the rules of the ancient law. In the kettle, first place an appropriate amount of starting materials, slow the fire and gradually heat up, so that the reaction can be slow. In the meantime, it is necessary to carefully observe the state of the kettle, such as changes in temperature and changes in the state of matter, and do not make it too hasty or too slow.
If the temperature is too high, the product will easily change and lose its purity; if the temperature is too low, the reaction will be slow and time-consuming. When the reaction is at the right time, collect the product in a delicate way. During this process, special attention should be paid to isolating other objects to prevent impurities from mixing.
And at the time of operation, the procedures must be strictly followed to prevent accidents. After the collection is completed, the refining technique is performed to remove its impurities and improve its purity, and pure tetrachloroethane can be obtained. The whole process requires a craftsman's heart as fine as hair and skilled in order to achieve this good product and produce the required tetrachloroethane.

Mercury is the cheapest substance in the world. However, it is used for its own purposes. Not only hardware can be used as an elite, that is, dansha, realgar, and herbal ash powder. Non-mercury cannot be changed. On the impact of mercury, two, three, four, and pentachloride - tetrachlorine - on the environment.
Mercury is toxic and highly volatile, and can be transported over long distances in the environment. It can be transported through the atmosphere, water, soil and other media. Mercury compounds, such as mercury dichloride, mercury trichloride, mercury tetrachloride, and mercury pentachloride, have different properties and have different effects on the environment.
Mercury dichloride, also known as mercury, is highly toxic, has high solubility in water, and is easily absorbed and enriched by organisms. It can damage the nervous system, reproductive system, etc. of aquatic organisms, and destroy the balance of aquatic ecology. If it enters the soil, it can reduce the activity of soil microorganisms and affect soil nutrient cycling and material transformation.
Mercury trichloride has less stability and can gradually decompose and transform in the environment. However, its decomposition products may still be toxic, can pollute water and soil, and endanger the survival of surrounding organisms.
Mercury tetrachloride is relatively stable, but under specific environmental conditions, it can undergo photolysis or biotransformation. It can affect algal growth and photosynthesis in water, and indirectly affect food chain upper organisms. And because of its fat solubility, it is easy to accumulate in organisms, threatening biological health.
Mercury pentachloride, although relatively rare, its toxicity should not be underestimated. It may have a significant impact on the structure and function of microbial communities in the environment, interfering with the normal metabolism and material cycle of the ecosystem.
Tetrachloride compounds, if not properly disposed of in the environment, can cause the accumulation of chlorine elements. Excessive chlorine elements may change the pH of the soil, affect the absorption of nutrients by plants, and damage the soil structure. In water bodies, it may cause eutrophication of water bodies, cause excessive algae reproduction, cause hypoxia in water bodies, and endanger aquatic organisms.
In summary, mercury and its chlorides are very harmful in the environment, and our generation should be careful to prevent them from causing irreversible damage to the environment.