1,2-Dibromoethane, in the ancient times involved in "Tiangong Kaiwu", although there is no such precise chemical name, it can be compared to the related things at that time due to its chemical properties and use. Its main uses are as follows:
First, in the field of organic synthesis, 1,2-dibromoethane can be used as an important intermediate. In the chemical preparation of ancient times, although the techniques are very different from today, various media are also required to promote the reaction. Such as ancient lacquer making, pharmaceutical and other processes, or similar to 1,2-dibromoethane, to help various components blend and react to form the desired product.
The second, 1,2-dibromoethane has good flame retardancy. The fire prevention of ancient buildings and fabrics is quite important. Although there was no name of modern fire retardants at that time, it may have been found that certain substances can reduce the flammability of flammable materials. If 1,2-dibromoethane was available at that time, it could be used to treat fabrics and building materials to reduce fire hazards.
Third, in agricultural deworming, 1,2-dibromoethane can be used as a fumigant. In ancient agriculture, pests often disrupted the harvest. Fumigation method, using the volatile gas of drugs to exterminate insects. The characteristics of 1,2-dibromoethane may make it the choice of farmers to exterminate insects and protect crops from pests at that time.
Fourth, 1,2-dibromoethane can be used as a solvent in analytical chemistry. Ancient alchemy, pharmaceuticals and other activities required dissolving all kinds of gold stones, herbs and medicinal herbs. 1,2-dibromoethane's dissolving capacity, or assisting the ancients to dissolve insoluble medicinal materials to extract active ingredients for medicinal pill refining and pharmaceutical preparation.

1% 2C2-dibromoethane, also known as ethylene-dibromide, is an organic compound. Its physical properties are as follows:
In appearance, under room temperature and pressure, 1,2-dibromoethane appears as a colorless, transparent and volatile liquid. Under the influence of light, it will gradually decompose to form bromine, causing its color to be slightly yellow. Its odor is unique, with a sweet aroma similar to chloroform.
When it comes to the melting point, the melting point of this substance is 9.3 ° C, and the boiling point is 131.4 ° C. Because of its relatively high boiling point, it exists in liquid form in general environment and has good stability.
1,2-dibromoethane has a density of 2.17g/cm ³, which is heavier than water. If mixed with water, it will sink to the bottom of the water and appear stratified.
In terms of solubility, 1,2-dibromoethane is difficult to dissolve in water, but it can be miscible with ethanol, ether, chloroform and many other organic solvents in any ratio. This characteristic is due to its molecular structure being similar to that of organic solvents and following the principle of "similar miscibility".
In addition, the vapor pressure of 1,2-dibromoethane is about 1.17kPa at 20 ° C, indicating that it is moderately volatile and will evaporate slowly in air. At the same time, its refractive index is 1.538 (20 ° C), and when light passes through 1,2-dibromoethane, the direction of light changes according to this specific refractive index.

1,2-Dibromoethane is an organic compound with the following properties:
In terms of view, it is a colorless, transparent and volatile liquid, with a sweet smell like chloroform. Its density is higher than that of water, about 2.17g/cm ³. Compared with water, it is difficult to dissolve in water, but it can be miscible with organic solvents such as ethanol, ether, and chloroform.
In terms of chemical properties, in 1,2-dibromoethane, the activity of bromine atoms is quite high. First, a substitution reaction can occur. In alkaline aqueous solutions, bromine atoms can be replaced by hydroxyl groups to generate ethylene glycol; in alcohol solutions and under heating conditions, an elimination reaction can occur to remove two molecules of hydrogen bromide and generate acetylene. Second, 1,2-dibromoethane can also participate in nucleophilic substitution reactions, such as the reaction with sodium cyanide, the bromine atom will be replaced by a cyanyl group to form succinonitrile. Furthermore, because of its carbon-bromine bond, when heated or illuminated, the carbon-bromine bond may be homogenized, generating free radicals, which in turn triggers free radical reactions.
1,2-dibromoethane is widely used in industrial fields, often used as a solvent, and is also an important intermediate for the preparation of various organic compounds. It plays a key role in organic synthesis chemistry.

There are several methods for preparing 1% 2C2-dibromoethane. The method can be obtained by the addition reaction of ethylene and bromine. In ancient chemical technology, to make this 1% 2C2-dibromoethane, the following methods are often used:
In a secret chamber, prepare various vessels in a kettle. First take the ethylene gas, which should be pure and free of impurities, and can be obtained by dehydration of ethanol catalyzed by concentrated sulfuric acid. The obtained ethylene is introduced into a container containing bromine by a conduit. Bromine is red-brown in color and strong in nature, with strong oxidizing properties. When ethylene is added to bromine, the two meet and combine to form an addition reaction. The reaction formula is as follows: $CH_2 = CH_2 + Br_2\ longrightarrow CH_2BrCH_2Br $.
When reacting, it is advisable to observe its situation. Because the reaction has a large amount of heat, it is necessary to control its temperature and do not overheat to prevent accidental changes. Or set up a cooling device and surround the kettle with water to slow the heat dissipation and make the reaction go smoothly.
There is another way, which can be used to add acetylene and hydrogen bromide first to obtain ethylene bromide, and then add ethylene bromide to bromide, and also to obtain 1% 2C2-dibromoethane. First, the acetylene and hydrogen bromide are met under specific conditions, and the catalyst is supplemented to obtain ethylene bromide. Then, vinyl bromide is combined with bromine to form 1% 2C2-dibromoethane. However, compared with this two methods, the former method of direct addition of ethylene and bromine is more straightforward and simple, and is more commonly used in ancient chemical preparation. After preparation, the obtained 1% 2C2-dibromoethane can be distilled to remove its impurities to obtain a pure product.

1% 2C2-dibromoethane is an organic compound with strong and toxic properties. When used, many things must be observed.
The first thing to pay attention to is its toxicity. This substance can invade the human body through the respiratory tract, skin and digestive tract, harming the central nervous system, liver and kidneys. When using it, be sure to take comprehensive protection. Wear protective clothing, protective gloves and a gas mask to prevent contact and inhalation.
It is related to its flammability. 1% 2C2-dibromoethane is flammable. In case of open flames and hot topics, it is very easy to explode. Therefore, where it is used, fireworks should be strictly prohibited, and fire extinguishing facilities should be equipped to prevent accidents.
Furthermore, its storage is also exquisite. It needs to be stored in a cool and ventilated place, away from fire and heat sources. It should not be stored with oxidants and acids to avoid reactions.
Repeat, when operating, the action should be slow and careful. Avoid its leakage. If it leaks accidentally, take measures as soon as possible. Small leaks can be absorbed by inert materials such as sand and vermiculite; large leaks need to be built embankments or dug for containment before disposal.
In addition, after use, its waste should not be disposed of at will. It should be handled by qualified units in accordance with relevant regulations, and must not be dumped at will to avoid pollution and the environment. < Br >
Use 1% 2C2-dibromoethane, safety is the priority, and all precautions must be strictly followed to ensure safe operation and avoid disasters.