Vapor pressure of helium at different temperatures

Vapor pressure of helium at different temperatures Junjie Chen Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: [e-mail] Helium is a chemical element, inert gas of Group 18 of the periodic table. The second lightest element (only hydrogen is lighter), helium is a colourless, odourless, and tasteless gas that becomes liquid at temperature of -268.9 degrees Celsius. The boiling and freezing points of helium are lower than those of any other known substance. Helium is the only element that cannot be solidified by sufficient cooling at normal atmospheric pressure; it is necessary to apply pressure of 25 atmospheres at a temperature of -272 degrees Celsius to convert it to its solid form. Helium gas is isolated from natural gas by liquefying the other components at low temperatures and under high pressures. Adsorption of other gases on cooled, activated charcoal yields 99.995 percent pure helium. Some helium is supplied from liquefaction of air on a large scale; the amount of helium obtainable from 1,000 tons of air is about 3.17 cubic metres, as measured at room temperature and at normal atmospheric pressure. Helium is used as an inert-gas atmosphere for welding metals such as aluminum; in rocket propulsion (to pressurize fuel tanks, especially those for liquid hydrogen, because only helium is still a gas at liquid-hydrogen temperature); in meteorology (as a lifting gas for instrument-carrying balloons); and in cryogenics (as a coolant because liquid helium is the coldest substance). Meteorites and rocks have been analyzed for helium content as a means of dating. Temperature (degrees kelvin), Pressure (kilopascals) 2.2 5.332 2.3 6.725 2.4 8.351 2.5 10.23 2.6 12.38 2.7 14.81 2.8 17.56 2.9 20.64 3 24.06 3.1 27.85 3.2 32.02 3.3 36.6 3.4 41.6 3.5 47.04 3.6 52.94 3.7 59.31 3.8 66.19 3.9 73.58 4 81.51 4.1 90 4.2 99.08 4.3 108.8 4.4 119.1 4.5 130.1 4.6 141.7 4.7 154.1 4.8 167.3 4.9 181.3 5 196.2 5.1 212.1 Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: [e-mail], Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China