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不同温度下氦的蒸气压 陈俊杰 河南理工大学机械与动力工程学院能源与动力工程系，中国河南省焦作市世纪大道2000号，454000 贡献者：陈俊杰，ORCID：0000-0001-5055-4309，电子邮箱：[e-mail] 氦是一种化学元素，属于周期表第18族惰性气体。它是第二轻的元素（仅氢比其更轻），为无色、无臭、无味的气体，在-268.9摄氏度时会转变为液态。氦的沸点与凝固点均低于所有已知物质，是唯一一种在标准大气压下无法通过充分冷却实现固化的元素；若要将其转化为固态，需在-272摄氏度的温度下施加25标准大气压的压力。 氦气可通过在低温高压环境下将天然气中的其他组分液化，从天然气中分离得到。将其他气体吸附于冷却后的活性炭上，可获得纯度达99.995%的氦气。部分氦气可通过大规模液化空气获取：在室温与标准大气压下，从1000吨空气中可提取约3.17立方米的氦气。 氦气可用作焊接铝等金属时的惰性保护气氛；用于火箭推进系统，为燃料罐（尤其是液氢燃料罐）加压，因为仅氦气在液氢温度下仍保持气态；在气象学中作为搭载科学仪器的气球的升力气体；以及在低温工程中用作制冷剂，因为液氦是已知最冷的物质。 人们可通过分析陨石与岩石中的氦含量来进行年代测定。 温度（开尔文），压力（千帕） 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 3.0 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 4.0 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 5.0 196.2 5.1 212.1 贡献者：陈俊杰，ORCID：0000-0001-5055-4309，电子邮箱：[e-mail]，河南理工大学机械与动力工程学院能源与动力工程系，中国河南省焦作市世纪大道2000号，454000