![]() ![]() The reaction with water of liquid sodium having a high surface area can be explosive. Filtration and cold trapping also are effective in removal of gross quantities of carbonate, hydroxide, and hydride. A second technique for removing the oxide, called cold trapping, involves running the molten sodium through a cooled packed bed of material, upon which the oxide can precipitate. This low solubility is utilized to a considerable extent in continuous purification processes of the sodium in large liquid-metal reactor systems. ![]() Sodium that is heavily contaminated with the monoxide may be readily purified by filtration, since the solubility of the oxide in molten sodium is low. Another route to the superoxide is oxidation of sodium peroxide, Na 2O 2, treated to have a large surface area. The superoxide (NaO 2) can be prepared by heating metallic sodium to 300 ☌ (570 ☏) in an autoclave (a heated pressure vessel) containing oxygen at high pressure. Sodium monoxide (Na 2O) is ordinarily formed upon oxidation of sodium in dry air. Special dry-powder fire extinguishers are required, since sodium reacts with carbon dioxide, a common propellant in regular fire extinguishers. The temperature of burning sodium increases rapidly to more than 800 ☌ (1,500 ☏), and under these conditions the fire is extremely difficult to extinguish. In a comparatively dry atmosphere, sodium burns quietly, giving off a dense white caustic smoke, which can cause choking and coughing. It is significantly more reactive in air as a liquid than as a solid, and the liquid can ignite at about 125 ☌ (257 ☏). Sodium does not react with nitrogen, so sodium is usually kept immersed in a nitrogen atmosphere (or in inert liquids such as kerosene or naphtha). In ordinary air, sodium metal reacts to form a sodium hydroxide film, which can rapidly absorb carbon dioxide from the air, forming sodium bicarbonate. The corrosion of solid sodium by oxygen also is accelerated by the presence of small amounts of impurities in the sodium. Sodium is ordinarily quite reactive with air, and the reactivity is a function of the relative humidity, or water-vapour content of the air. Generally, elemental sodium is more reactive than lithium, and it reacts with water to form a strong base, sodium hydroxide (NaOH). SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.Britannica Beyond We’ve created a new place where questions are at the center of learning.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians. ![]() #Sodium element how to
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