1,3-Dihydro-benzoimidazole-2-thione

"Tiangong Kaiwu" has written that there are many kinds of alum stone, among which sulfur and saltpeter can be combined to obtain flame nitrate, which is widely used in military, fireworks and other fields. 1,3-dioxane-2-ketone, this chemical substance seems to be very far from the traditional things contained in "Tiangong Kaiwu", but it can also be explored by looking at ancient thinking.
From the perspective of "Tiangong Kaiwu", everything has its uses. The things produced by alum stone, such as flame nitrate, can make gunpowder in the military, greatly increasing the power of firearms and changing the pattern of war; in the manufacture of fireworks, it can bloom gorgeous fireworks and add to the joy of festivals.
And 1,3-dioxane-2-one, although it has no name in ancient times, is an important raw material for organic synthesis from a chemical perspective. In modern industry, it can participate in the synthesis of a variety of polymer materials, such as polyester products. Such materials can be used in the textile industry to make comfortable and durable fabrics; in the packaging industry, it can produce tough and moisture-proof packaging materials, which are widely used.
Furthermore, starting from the concept of "Tiangong Kaiwu" focusing on practicality and making the best use of everything, 1,3-dioxane-2-one can also be used in the field of medicine. It may be used as an intermediate in drug synthesis to help develop new drugs to relieve diseases and pains, which is also in line with the ancient idea of saving the world and saving people.
Although "Tiangong Kaiwu" does not directly state 1,3-dioxacyclohexane-2-one, it contains the spirit of material utilization and exploration, so that future generations can gain insight into the use of new substances when they appear, explore value in various fields such as industry and medicine, and continue the ancient tradition of exploring the function of all things.

Gypsum is a common mineral, and its physical properties are quite characteristic.
Looking at its color, pure gypsum is often white, but if it contains impurities, it will show different colors, such as gray, yellow, pink, etc. Its luster is also considerable, with a glassy luster, which is reflected in the light, as if there is a smart optical flow, which is quite beautiful.
When it comes to hardness, gypsum has a low hardness. The Mohs hardness is about 2, and it can be scratched with a fingernail. This characteristic makes it easy to carve and shape. In ancient times, craftsmen often used this characteristic to carve it into exquisite utensils and decorative objects.
In addition to its cleavage, gypsum has a set of extremely complete cleavage, which is easy to split along the cleavage surface. The cleavage surface is smooth like a mirror, which is amazing. Its fracture is shell-like or flat, which is also a manifestation of its physical properties.
The density of gypsum is relatively small, about 2.3 grams/cubic centimeter. When held in the hand, it feels light to the touch, which is unique compared with many heavy ores.
In addition, gypsum has a certain degree of water absorption. When placed in the air, it can absorb a little moisture, and when exposed to water, it will undergo a hydration reaction and gradually harden into shape. This property makes it widely used in many fields such as construction. The ancients also had early insight into its nature, and when building, they skillfully used plaster to enhance the stability and beauty of the structure.

The nature of phosphoric acid is often doubted by the world whether it is stable or not. Today's detailed analysis.
Phosphoric acid is also an inorganic acid. It is acidic, but compared with strong acids, such as sulfuric acid and hydrochloric acid, phosphoric acid is slightly less acidic. This is because its ability to dissociate hydrogen ions in water is limited, only partially ionized, so the acidity is not as strong as strong acid.
In terms of stability, under normal conditions, phosphoric acid is quite stable. In its chemical structure, phosphorus atoms and oxygen atoms are connected by covalent bonds to form a stable structure. And phosphoric acid is not easy to volatilize and decompose under normal temperature and pressure.
However, when encountering special conditions, the stability may change. If the temperature rises to a certain extent, phosphoric acid may dehydrate and form polymers such as pyrophosphoric acid. For example, in a specific catalyst and reaction environment, phosphoric acid can participate in various chemical reactions, and its stability will be affected at this time.
Looking at it again, the stability of phosphoric acid is also reflected in its chemical inertness to many substances. In general environments, phosphoric acid does not react violently with most metals and organics unless there are suitable conditions, such as specific pH, temperature and catalyst.
To sum up, under common conditions, the chemical properties of phosphoric acid are stable, but in special environments, its stability or variable. Therefore, the stability of phosphoric acid depends on specific conditions.

To make dicyandiamide, also known as cyanodiamide, there are three methods.
First, start with lime nitrogen. Mix lime nitrogen with water, form a suspended state, and put it in the reactor. The temperature is controlled at a specific degree, usually tens of degrees Celsius, and carbon dioxide gas is slowly introduced. The two then react. Lime nitrogen first hydrolyzes in water, and then interacts with carbon dioxide. After complex changes, it finally obtains dicyandiamide. This process requires precise temperature control and aeration rate to ensure a smooth reaction and improve the purity and yield of the product. After the reaction, pure dicyandiamide can be obtained by separation and purification methods, such as filtration and crystallization.
Second, cyanamide is used as the source. Cyanamide is polymerized under specific conditions, either by heating or with the help of a catalyst, to generate dicyandiamide. The key to this approach is to find suitable reaction conditions and efficient catalysts. The appropriate temperature and pressure have a great impact on the reaction process. If the temperature is too high or side reactions are caused, if it is too low, the reaction will be slow. Excellent catalysts can speed up the reaction rate and improve the selectivity of products. However, finding such catalysts requires many tests and investigations.
Third, urea is used as a base. Heat urea to a high temperature and decompose it into cyanic acid and ammonia first. Cyanic acid reacts with ammonia and gradually converts into dicyandiamide. The temperature control of this process is crucial. Although high temperature can promote the fast-forward reaction, it is easy to cause the decomposition of the product. At the same time, the pH of the reaction environment, reaction time and other factors also affect the quality and yield of the product. Fine debugging is required to achieve the ideal preparation effect.
These three methods have their own advantages and disadvantages. In actual preparation, careful choices should be made according to factors such as the availability of raw materials, cost, and product requirements.

1% 2C3, is the genus of fire. Dioxy, a kind of gas, colorless and odorless, widely distributed in the world. Boron and sulfur, special and widely used. As for the two, or a sign of quantity. Gypsum has many uses and is useful in various fields.
In the field of medicine, gypsum has the ability to clear away heat and purge fire. Ancient doctors often used gypsum to treat all kinds of heat syndromes. If a person has an exogenous fever, a hot topic is thirsty, and the agent of gypsum can relieve its heat and remove its annoyance. Cover the cold nature of gypsum, can clear the heat of the lungs and stomach, so that the evil heat has a way out, and the disease is cured. < Br >
In the world of manufacturing, gypsum is also indispensable. It can be used as a model material, which is hard and delicate after condensation, and can be made into a delicate mold to help the manufacture of objects. Such as casting copper tools, first use gypsum to make molds, and then pour copper into them, to be cold formed, to obtain exquisite tools.
In the context of architecture, gypsum can be used as a decorative material. It can be made into gypsum board for ceiling and partition walls. It is light in weight, and has the effect of sound insulation and heat insulation, which can make the residence more comfortable. It can also be carved into various pattern patterns to increase the beauty of the building.
In the domain of agriculture, gypsum is also wonderfully used. It can improve the soil. If the soil is heavy in alkali, applying gypsum can reduce its alkalinity, make the soil suitable for cultivation, help the growth of grains, and enrich the harvest of farmers.
Therefore, the use of gypsum is widely involved in the fields of medicine, industry, construction, and agriculture, and is an indispensable material in the world.