5-bromopyridine-2-carbonitrile

Zinc is one of the hardware, its quality is unique, with various physical properties.
The color of zinc is silver-white and slightly bluish, and it shines brightly, just like the moonlight pouring on it. It is loved when viewed. Its texture is slightly brittle and hard, but after being suitably tempered, it can also become flexible and can be molded into various shapes for craftsmanship.
The melting point of zinc is quite impressive, about 419.53 degrees Celsius. When heated to this temperature, zinc gradually melts from a solid state to a liquid state, just like ice and snow in the warm sun. This property is widely used in casting processes. Craftsmen can pour liquid zinc into a specific mold, and when it cools and solidifies, it can be formed into a desired utensil.
The boiling point of zinc is also very high, about 907 degrees Celsius. At this high temperature, zinc will turn into a gaseous state and escape between heaven and earth. The characteristics of this boiling point have important uses in many fields such as metallurgy.
Furthermore, zinc has good electrical conductivity, although it is slightly inferior to metals such as gold, silver and copper, it is also an excellent material for conducting electricity. In many electrical devices, zinc is often used as a conductive component to ensure the smooth passage of current and enable the normal operation of the device.
In addition, zinc has high thermal conductivity. When one side is heated, the heat can be quickly transferred to the other side, like a messenger speeding to convey a message. This heat conductivity is very useful in making cooking utensils, etc., which can make food evenly heated and cook delicious dishes.
The various physical properties of zinc are actually wonders of creation. They play a key role in many aspects of work, agriculture, and life, and contribute a lot to the development and progress of mankind.

Lead and mercury are commonly used in ancient alchemy. Lead is heavy in nature, blue and gray in color, soft and malleable. Its chemical properties are all kinds of wonderful things. At room temperature, lead can slowly combine with oxygen in the air to form a dense lead oxide film, which can prevent further oxidation of lead. When it encounters acid, if it is dilute sulfuric acid, because lead sulfate is insoluble in water, it coats the surface of lead, and the reaction gradually stops; when it encounters nitric acid, lead can react violently with it to form lead nitrate and nitrogen oxides.
Mercury, also known as mercury, is the only liquid metal at room temperature, with a silver-white color and a metallic luster. The chemical properties of mercury are also different. Its activity is weak, it is very stable in the air, and it is not easy to combine directly with oxygen. However, when heated to a certain temperature, mercury can combine with oxygen to form mercury oxide. Mercury can dissolve many metals and form amalgam, which is often used in ancient metallurgy and alchemy.
The ancients used lead and mercury as the medicine for alchemy, hoping to use its chemical changes to refine the elixir of longevity. However, lead and mercury are all toxic. Long-term use of lead and mercury-containing elixirs not only cannot prolong life, but also cause damage to the body and poisoning. Today's chemistry has detailed the properties of lead and mercury, which is not what the ancients knew. However, the exploration of lead and mercury in ancient alchemy is also an important process in the evolution of chemical knowledge.

It is a common organic compound. Although the method of synthesis was not well known to the ancients, it can be described as follows in today's chemical knowledge.
First, the Williamson synthesis method. This is a commonly used method for preparing ethers. The halogenated hydrocarbon interacts with sodium alcohol, and the halogen atom in the halogenated hydrocarbon is replaced by an alkoxy group to form an ether. To make methyl ether, halomethane can be reacted with sodium methoxide. Halomethane such as chloromethane has good activity, and sodium methoxide is obtained by the reaction of methanol and sodium metal. When the two meet, the chlorine atom in the chloromethane leaves, and the methoxy group of sodium methoxide combines with it, and the methyl ether is formed. The reaction formula can be expressed as: $CH_3Cl + CH_3ONa\ longrightarrow CH_3OCH_3 + NaCl $. This reaction condition is relatively mild, and it can occur smoothly in an appropriate solvent such as ethanol solution under a certain temperature control.
Second, alcohol dehydration method. Methanol can undergo intermolecular dehydration to form methyl ether under appropriate catalysts and conditions. Concentrated sulfuric acid or alumina is often used as a catalyst. Taking concentrated sulfuric acid as an example, under the catalysis of methanol, the hydrogen of the hydroxyl group of methanol and the hydroxyl group of another molecule of methanol combine to form water to dehydrate, and the rest of the two methanol are connected to form methyl ether. Pay attention to the control of temperature during the reaction. If the temperature is too high, methanol is prone to intramolecular dehydration to form ethylene. Generally, the temperature is controlled in an appropriate range, such as 140 dollars ^ {\ circ} C $, and the reaction formula is: $2CH_3OH\ xrightarrow [140 ^ {\ circ} C] {concentrated sulfuric acid} CH_3OCH_3 + H_2O $.
Third, the methylation reagent method. For example, methylation reagents such as dimethyl sulfate are used to react with alcohols or phenolic compounds. Dimethyl sulfate has high activity. When reacting with sodium methoxide, the methyl group of dimethyl sulfate can replace the position of sodium in sodium methoxide to form methyl ether. Although this reaction can produce methyl ether, dimethyl sulfate is highly toxic, and special caution is required when using it. The post-reaction treatment is more complicated, because the by-products produced need to be properly handled.
All of these methods can be used to synthesize methyl ether, each with its own advantages and disadvantages, and should be selected according to the actual situation, such as the availability of raw materials, cost, and difficulty of reaction conditions.

"Tiangong Kaiwu" says: "The length of hardware, after melting and forming, will never change in the world." Among hardware, gold is the most expensive, silver is the second, and lead is the second. Lead is black and soft, heavy and toxic, but it is also widely used.
Lead is used in the field of casting tools and has many uses. In ancient times, money was often made of lead-tin alloy, which made the texture of money more tough and not easy to wear. And lead has a low melting point and is easy to cast. It can be used in various shapes, such as lead pots and lead cans. It is also seen in daily use.
In the field of protection, the application of lead is also indispensable. Because of its heavy nature and ability to block radiation, it is often used in places to protect against radiation. For example, in hospitals, lead plates are often used to protect the human body from radiation when performing certain fluoroscopy techniques. In smelting sites, lead can also protect workers from toxic fumes.
Furthermore, in the field of construction, lead also has its uses. Lead plates can be used for roof waterproofing, and their ductility is good. They can fit tightly to the roof and block the penetration of rainwater. And lead has strong corrosion resistance and can be used for a long time, providing stable protection for houses.
As for zinc, in the era described in "Tiangong Kaiwu", although it was not as widely used as lead, it also emerged. Zinc is often cast in brass with copper in the field of metallurgy. Brass is golden in color, shiny, hard in texture and not easy to deform. It is often used to make various appliances, such as bell tripods, incense burners, etc., which are both beautiful and durable.
In addition, zinc also has anti-corrosion effects. Plating zinc on the surface of iron can form a protective film to prevent iron from rusting and prolong the service life of iron. In construction and daily necessities, galvanized iron is quite common, which is also the function of zinc.

In today's world, business conditions are ever-changing, and the price of grains also moves with the market. As for the market prices of Wulang Liquid and Sorghum, it is necessary to carefully examine the current situation to determine.
The husband of Wulang Liquid is the famous brew of the country. Its craftsmanship is complicated, the materials are well-selected, the reputation is far-reaching, and there are many drinkers. Its price also rises and falls from time to time due to the age, origin, quality, supply and demand. The price of ordinary products in the city can range from hundreds of dollars; if it is an aged wine, it is not surprising that it can cost thousands of dollars. Gai is expensive because of its brand reputation, excellent craftsmanship, and good drinking in the world.
And sorghum, one of the five grains, is not only food, but also a material for winemaking. Its price is affected by the weather, geographical location, political strategy, merchants hoarding and other things. In a good year, sorghum is widely available, and the supply exceeds the demand, so the price becomes flat; in a disaster year, the harvest decreases sharply, and the supply exceeds the demand, the price will rise. And its uses are diverse, and the need for winemaking also affects its price. In the city, the price of ordinary sorghum per bucket or tens of dollars; if it is a good variety, the price is different.
In general, the market price of five sorghum liquid and sorghum depends on the weather, geographical location, people and people, and the supply and demand of the city. To know the exact price, you must check the current market situation, and cannot be generalized.