3H2+N2==2NH3 (the reaction is reversible, and the reaction conditions on the equal sign are "high temperature and high pressure" and the following "catalyst").
German chemist F. Haber (1868- 1934) began to study the direct synthesis of ammonia from nitrogen and hydrogen. 1908 applied for a patent, that is, the "recycling method". On this basis, he continued his research and improved the synthesis at 1909, and the ammonia content reached more than 6.
This is a direct synthesis method widely used in industry. In order to solve the problem of low conversion rate of hydrogen and nitrogen in the reaction process, after the synthesis reaction, the ammonia product was separated from the gas, and the unreacted gas was mixed with fresh hydrogen and nitrogen to participate in the synthesis reaction again.
Extended data:
When nitrogen is cooled to-195.8℃, it becomes a colorless liquid, and when it is cooled to -209.8℃, liquid nitrogen becomes a snow-like solid. Nitrogen is chemically inactive and difficult to react with other substances at room temperature, so it is often used to make preservatives. But under the condition of high temperature and high energy, it can change chemically with some substances and make new substances useful to human beings.
Nitrogen is chemically inert and is often used as a protective gas, such as fruit, food and light bulb filling gas. In order to prevent some objects from being oxidized by oxygen when exposed to the air, filling nitrogen into the granary can keep the grain from mildew and germination for a long time.
Liquid nitrogen can also be used as a deep refrigerant. As a refrigerant, it is often used in hospital freckle, steamed stuffed bun and bean surgery, that is, frozen spots, steamed stuffed bun and beans, but it is easy to scar and is not recommended.
References:
Baidu encyclopedia-nitrogen