Nitrogen, a chemical element (chemical sign N, atomic weight — 14) is one of the chemical elements; a colorless gas with no odor, no taste; very slightly soluble in water. Specific weight 0,972.
When in the gaseous state Nitrogen is the main component part of air. Critical connection A. : 1) with oxygen: nitrous oxide, nitric oxide, nitrous acid, attaway anhydride and nitric acid; 2) with hydrogen: ammonia (and its organic derivatives, such as, eg., aniline) and hydroxylamine; 3)with carbon CYANOGEN. In the liquid state (temp. boiling point -195,8 °C) is a colorless, mobile, like water, fluid.
Application
Liquid nitrogen is applied in kryotherapie.
Industrial uses of nitrogen gas due to its inert properties. Gaseous nitrogen is fire – and explosion-proof, prevents oxidation, decay. In the petrochemical industry nitrogen is used to purge tanks and pipelines, inspection of pipelines under pressure, increasing the production of deposits. In the mining case, the nitrogen can be used to create explosion-proof environment for the spreading of rock formations. In the manufacture of electronics nitrogen is used to purge areas that do not allow the presence of oxidizing oxygen. If in the process, traditionally held with the use of air, oxidation or rotting are negative factors — nitrogen can successfully replace the air.
Large quantities of nitrogen are used in coke production (“coke dry quenching”) when discharging coke from coke oven batteries and also for “kinked” fuel missiles from the tanks to the pumps or motors.
In the food industry nitrogen is a dietary Supplement E941, as a gas environment for packaging and storage, liquid nitrogen is used when pouring oils and non-carbonated beverages to create excess pressure and the inert medium in the soft container .
Liquid nitrogen is often shown in movies as a substance that can instantly freeze a large object. This is a widespread mistake. It takes quite a long time even to freeze a flower. This is partly due to the very low heat capacity of nitrogen.
Litre of liquid nitrogen being evaporated and is heated to 20°C, forms a roughly 700 gallons of gas. For this reason, liquid nitrogen is stored in special Dewar containers under pressure. On this fact is based the principle of extinguishing fires owith liquid nitrogen. Evaporating nitrogen displaces the oxygen necessary for combustion, and the fire stops. Since nitrogen, unlike water, foam or powder, simply evaporates and disappears, nitric fireextinguishing is the most effective from the point of view of safety.
