4-Pyridinemethanamine, 2-chloro-

Mercury is a metallic element and its chemical symbol is Hg. Mercury has different properties. It is a liquid at room temperature, with a shimmering silver light and a beautiful appearance.
Mercury is chemically active and can react with many substances. It can combine with oxygen to form mercury oxide. Under heating conditions, mercury reacts with oxygen more rapidly, and red mercury oxide powder is formed on the surface of mercury. The literal expression of this reaction is: mercury + oxygen $\ stackrel {heating} {→} $mercury oxide.
Mercury can also react with sulfur, and when they meet, they can quickly combine to form mercury sulfide. This property is often used to treat spilled mercury. Sprinkle sulfur powder on mercury droplets, and mercury will combine with sulfur to form relatively stable and non-toxic mercury sulfide to avoid the risk of poisoning caused by mercury volatilization. The literal expression of the reaction is: mercury + sulfur → mercury sulfide.
Furthermore, mercury has certain metal activity and can replace some metal salt solutions. For example, when mercury is put into a silver nitrate solution, mercury will replace silver, and the color of the solution will gradually change. At the same time, silver will precipitate on the surface of mercury. The literal expression of the reaction is: mercury + silver nitrate → mercury nitrate + silver.
In conclusion, although mercury has a unique physical state, its chemical properties are active. When using and handling mercury, it is necessary to follow safety regulations to prevent mercury from causing harm to humans and the environment.

The common preparation methods are as follows:
First, acetylene is used as the starting material. Acetylene reacts with sodium amide in liquid ammonia, and liquid ammonia provides a low-temperature stable environment as a solvent. Acetylene has acidic hydrogen, which can react with amino negative ions in sodium amide to generate sodium acetylene and ammonia. In this reaction, sodium amide is highly alkaline and can capture acidic hydrogen acetylene. For example, the acetylene gas is slowly introduced into the liquid ammonia solution containing sodium amide. At low temperature (about -33 ° C, the boiling point of liquid ammonia), the reaction proceeds smoothly to produce a white solid of sodium acetylene suspended in liquid ammonia.
Second, through the elimination reaction of halogenated alkanes. Using o-dihaloalkane as raw material, it is co-heated with a strong base (such as potassium hydroxide alcohol solution) to undergo a two-step elimination reaction to obtain alkynes. Two halogen atoms in o-dihaloalkane and hydrogen atoms on adjacent carbon atoms, under the action of strong bases, two molecules of hydrogen halide are removed to form carbon-carbon triple bonds. For example, when 1,2-dibromoethane is heated with a potassium hydroxide alcohol solution, a molecule of hydrogen bromide is first eliminated to form bromoethylene. Bromoethylene continues to react with strong bases, and then a molecule of hydrogen bromide is eliminated to form acetylene. Then acetylene reacts with sodium amide to obtain sodium acetylene.
Third, the alkyl dihaloalkane is used as the raw material, and the alkyl dihaloalkane reacts with a strong base (such as potassium tert-butanol, etc.) in an appropriate solvent (such as tetrahydrofuran). The alkyl dihaloalkane is eliminated to form alkynes, and then reacts with sodium amide to obtain sodium alkyne. The two halogen atoms of the alkyl dihaloalkane are connected to the same carbon atom. Under the action of a strong base, a carbon-carbon triple bond is formed between the carbon atom and the adjacent carbon atom. For example, 1,1-dibromoethane reacts with potassium tert-butanol in tetrahydrofuran to form acetylene and then produce sodium alkyne.

A certain student asked me: "Mercury and four-way armor are used in what fields?" This question concerns the application of mercury and the so-called "four-way armor".
Mercury, commonly known as mercury, is the only metal that is liquid at room temperature and pressure. Its application is quite extensive. In the medical field, it was used to make thermometers in the past, using its thermal expansion and contraction characteristics to measure body temperature, but now it is gradually being replaced due to its toxicity. In the chemical industry, mercury can be used as a catalyst to help many chemical reactions proceed. For example, in the chlor-alkali industry, mercury cathode method was used to produce caustic soda and chlorine gas; in the electronics industry, mercury is also used. For example, mercury is contained in fluorescent lamps. When powered on, mercury vapor discharges to generate ultraviolet rays, which excites phosphors to emit light.
As for the "four-way armor", the ancient armor, its application is mainly in the field of military warfare. Soldiers wearing armor can defend against the attack of enemy swords, guns and arrows, protect their bodies and improve the chances of survival on the battlefield. When the battlefield is charged and close to each other, the strong armor can reduce the damage caused by the blade. In addition, in some important ceremonial occasions, the armor also has symbolic significance, highlighting the wearer's status and military authority, and showing the majesty and momentum of the army.

The city of the sea is a place where commerce and people gather, and its prosperity can be achieved. However, if you want to understand the prospects of the city, you must not fail to explore it.
The city of the sea, the land is important and the water is convenient for transportation, and the sky is thick and thick. The boat is going to the city, and the business of the four directions is gathered here. It is easy to do, and there is a reason. Moreover, the light of the land is beautiful, and the sea is a place where people are attracted. The business of the city also flourishes, and the prosperity of the city is added.
However, the prospect of the city does not depend on its inherent benefits. In today's world, technology is changing with each passing day, and the business model is not difficult. If you want to maintain prosperity, you must create trends and promote new ones. In the words of children and merchants, the city of the sea should make good use of its sources, build a platform for transactions, and expand business routes, so that the goods can be carried out in the world.
Furthermore, the importance of protection cannot be ignored. The beauty of the sea is its treasure. If the environment is broken due to the business, it will be exhausted.
To be able to support the development of ideas, so that the business can be protected and the benefits can be enjoyed for a long time.
Those who also have talents are the root of the work. The city of the sea, if you want to take steps to meet the needs, must create new talents, encourage new ones, and use the power of wisdom and technology to promote the promotion of the world.
In this case, the city of the sea has not only obtained the thick pieces of the sky, but also faced the challenge of being replaced. If we can improve the quality of our products, innovate, and protect our talents, the prospects of our market will surely be as prosperous as ever.

Today there is hydrogen, and its safety in ethane is really related to all kinds of situations.
Hydrogen is the lightest gas, with high flammability, and can release huge amounts of heat energy when burned. If not properly disposed of, in case of ignition sources such as open flame and static electricity, it is very easy to cause violent combustion and even explosion, which is dangerous.
Ethane is also a flammable gas, which is gaseous at room temperature and pressure. However, compared with hydrogen, its density is slightly higher, it is easier to accumulate in air, and the explosion limit is different.
To discuss the safety of hydrogen in ethane, first look at storage. Hydrogen because of its small molecule, easy to leak, requires extremely high tightness and material of storage containers. If there are micro-gaps in the container, hydrogen may escape, reaching a certain concentration in the air, and it will be dangerous in case of fire. Although ethane also needs to be prevented from leaking, due to its relatively large molecule, the leakage difficulty is slightly less than that of hydrogen.
Second word transportation. The transportation of hydrogen requires special high-pressure vessels or low-temperature liquefaction equipment, which is expensive and technically complicated. If there is a slight error, if the container is damaged during transportation and hydrogen leaks, it is easy to cause disaster. Although ethane transportation is also standardized, compared with hydrogen, the technical difficulty and risk control are slightly easier.
Furthermore, the use scenario. In industrial hydrogen scenarios, such as chemical synthesis, if improperly operated, hydrogen leakage or explosion will threaten the lives of workers and the safety of facilities. In the field of energy, hydrogen fuel cells are increasingly used, and their safety needs to be carefully designed and strictly regulated. Ethane is often used in fuels and chemical raw materials, and it also needs to be carefully fireproof and explosion-proof when used, but its reactivity is slightly lower than that of hydrogen.
In summary, hydrogen and ethane have different safety considerations. Hydrogen has high energy density and broad prospects. However, due to its high activity and special physical properties, safety management challenges are considerable. Although ethane is relatively stable, it should not be taken lightly. Only good research and practice can ensure the safety of storage and transportation of the two.