Nitrogen density

Nitrogen is a simple substance formed by nitrogen, and the chemical formula is n? .

Nitrogen is the main component of air, and its volume fraction is about 78% (about 4/5), which is slightly lighter than air, and its density is 1 .25g/L. Under normal temperature and pressure,1volume of water only dissolves about 0.02 volume of nitrogen.

The molar mass of nitrogen is 28.01g/mol; The structural formula is N≡N4, the bond length is 109.8pm, and the bond energy is 948.9kJ/mol7, and the structure is stable. Colorless, odorless and nontoxic at normal temperature and pressure. Liquefied to liquid nitrogen at-195.8℃ and turned into snow-like solid at -209.9℃.

Nitrogen is chemically stable and can be directly combined with particularly active metals. Nitrogen can be used for fire fighting, and liquid nitrogen is often used as refrigerant. Nitrogen is often used as a protective gas in medicine, food processing, electrical protection and other fields, and it is also an important raw material for industrial synthetic ammonia and chemical fertilizer.

What are the applications of liquid nitrogen?

Liquid nitrogen is used in many applications because of its low reactivity and extremely low temperature.

1. IVF is used to cryopreserve biological samples, such as eggs, sperm and embryos, to preserve them.

2. Cryotherapy In cryotherapy, the human body is exposed to extremely low temperature for a period of time. It helps to treat abnormal skin conditions. This therapy is also used for athletes to relieve arthritis pain and paralyze any pain caused by injuries.

3. Machine It is used as a large coolant for vacuum pumps, superconductors and other equipment.

4. Hotel It is widely used in hotels to immediately freeze liquids or prepare instant ice cream. Now the formation of instant ice cream that we see in reality or online also needs liquid nitrogen, because it can immediately freeze the mixture needed to make ice cream.

Because of its characteristics, liquid nitrogen is used in various research and development activities.