What is liquid nitrogen

What is liquid nitrogen? Many people may not know much about it, let alone how to make it. It also plays a very important role in food production. For example, the ice cream we usually like to eat is made with food-grade liquid nitrogen, and some liquid nitrogen biscuits are also made with food-grade liquid nitrogen. Liquid nitrogen is also widely used in clinical practice, for removing moles and freckles, etc. Let us learn about liquid nitrogen below.

Liquid nitrogen: nitrogen gas in liquid form. It is inert, colorless, odorless, non-corrosive, non-flammable and extremely low temperature. Nitrogen makes up the majority of the atmosphere (78.03% by volume, 75.5% by weight). Nitrogen is inactive and does not support combustion. When vaporizing, it absorbs a large amount of heat and causes frostbite. Liquid nitrogen is inert, colorless, odorless, non-corrosive, non-flammable and extremely cold. Nitrogen makes up the majority of the atmosphere (78.03% by volume, 75.5% by weight). Nitrogen is inactive and does not support combustion; at normal pressure, the temperature of liquid nitrogen is -196°C; a cubic meter of liquid nitrogen can be expanded to 696 cubic meters of pure gaseous nitrogen at 21°C. Liquid nitrogen is a colorless, odorless, low-temperature liquid and gas under high pressure. When liquid nitrogen vaporizes at normal pressure, its volume expands 696.5 times.

Liquid nitrogen (often written as LN2) is the liquid form of nitrogen formed at low temperatures. The boiling point of nitrogen is -196°C. If the temperature is below this, liquid nitrogen will be formed under normal atmospheric pressure; if pressurized, liquid nitrogen can be obtained at a higher temperature. The human body can come into direct contact with liquid nitrogen, and according to the "Leidenfrost effect", the skin will not be frostbitten. In industry, liquid nitrogen is obtained by fractional distillation of air. The air is purified and then liquefied under pressure and cooling, and the components in the air are separated based on their different boiling points.