Helium
He · Helium-4 · helium, liquid · HELIUM · o-Helium · p-helium · Helium(0) · heliumgas
Identifikatoren & physikalische Daten
| CAS No. | 71086-78-7 |
|---|---|
| Summenformel | He |
| Durchschnittliche Molmasse | 4,0026 g/mol |
| Monoisotopische Masse | 4,00260325 g/mol |
| SMILES | [He] |
| InChIKey | SWQJXJOGLNCZEY-UHFFFAOYSA-N |
| PubChem CID | 23987 |
| ChEMBL | CHEMBL1796997 |
| ChEBI | CHEBI:33681 |
| EC No. | 231-168-5 |
| DTXSID | DTXSID7036402 |
| Lokaler Name | Helium |
Chemische & physikalische Eigenschaften
| Polarare Oberfläche (TPSA) | 0 |
|---|---|
| H-Brücken-Donoren | 0 |
| H-Brücken-Akzeptoren | 0 |
| Frei drehbare Bindungen | 0 |
| Schwere Atome | 1 |
| Formalladung | 0 |
| Komplexität | 0 |
| Stoffklassen | Toxic Gases & Vapors -> Simple Asphyxiants |
| SpringerMaterials Properties | electron-phonon coupling |
| LogP (Verteilungskoeffizient) | 0.28 |
| Geruch | Odorless |
| Geschmack | Tasteless |
| Lebensmittelzusatzstoffe | PROCESSING AID -> FDA Substance added to food |
| Dichte | 1.64 g/LLiquid helium has unique thermodynamic properties ... Refractive index 1,026, density 0.125 and is called a "quantum fluid" because it exhibits atomic properties on a macroscopic scale. Its BP is near absolute zero and viscosity is 25 micropoises (water = 10,000). He II, formed on cooling HE I below its transition point, has the usual property of superfluidity, extremely high thermal conductivity, and viscosity approaching zero.0.147 @ -270.8°C0.1785(0℃) |
| Viscosity | 1.953 at 20 °C, 0.1 MPa1.977 at 20 °C, 20 MPa |
| Color/Form | Colorless gasLiquid helium (He-4) exists in 2 forms: He-4 I and He-4 II, with a sharp transition point at 2.174 K (3.83 cm Hg) |
| Löslichkeit | 1.5mg/LVery slightly soluble in water: at 0 °C, 0.97 mL/100 mLat 50 °C, 1.08 mL/100 mLInsoluble in ethanolIn water, 2.50 mg/L at 21 °C2.5 mg/L @ 21C (exp)Solubility in water, ml/100ml at 20 °C: 0.86slightly soluble in H2O8.61mL/1000g H2O (101.32kPa, 0°C) [KIR78]Henry’s law constants, k×104: 9.856 (104°C), 6.739 (149.4°C), 2.524 (250.6°C), 1.796 (275.1°C) [POT78] |
| Human Drugs | FDA approved drugs -> Active ingredient |
| Animal Drugs | FDA approved animal drugs -> Active ingredient |
| Schmelzpunkt | -272.2 °C(lit.) |
| Siedepunkt | -268.934 °C(lit.) |
| Dampfdichte | 0.14 (vs air) |
| Aggregatzustand | gas |
| Farbe | colorless |
| Geruch | at 100.00%. odorless |
| Spezifische Wärmekapazität | Cp(gas): 5.2 J/(g·K), at 25℃ |
| Merck | 13,4645 |
| Henry-Konstante | 3.9×10-6 mol/(m3Pa) at 25℃, Fernández-Prini et al. (2003) |
| Dielektrizitätskonstante | 1.0(-269℃) |
| Stabilität | Stableextremely unreactive. |
| InChI | 1S/He |
| InChIKey | SWQJXJOGLNCZEY-UHFFFAOYSA-N |
| SMILES | [He] |
| LogP (Verteilungskoeffizient) | 0.280 |
| CAS Datenbank | 7440-59-7(CAS DataBase Reference) |
| EPA chemische Informationen | Helium (7440-59-7) |
Sicherheit & Vorschriften
| GHS-Einstufung | This chemical does not meet GHS hazard criteria for 0.4% (2 of 491) of reports.WarningH280 (65.6%): Contains gas under pressuremay explode if heated [Warning Gases under pressure]P282, P336+P317, P403, and P410+P403 (click each P-code to see the statement)Aggregated GHS information provided per 491 reports by companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies. |
|---|---|
| Regulatorische Informationen | Chemical: HeliumHelium is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Helium are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)Helium: Non hazardousThe New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.) |
| Weitere Sicherheitsinformationen | IMAP assessments - Helium: Human health tier I assessment |
| DOT-Kennzeichnung | Non-Flammable Gas |
| Brandgefahren | Excerpt from ERG Guide 120 [Gases - Inert (Including Refrigerated Liquids)]:· Non-flammable gases.Not combustible. Heating will cause rise in pressure with risk of bursting. |
| Brandpotenzial | Not combustible. Heating will cause rise in pressure with risk of bursting. |
| Gesundheitsgefahren | Excerpt from ERG Guide 120 [Gases - Inert (Including Refrigerated Liquids)]:· Vapors may cause dizziness or asphyxiation without warning, especially when in closed or confined areas. |
| Gefahrenübersicht | Simple asphyxiantEvaporating liquid can cause frostbite[ICSC] |
| DOT-Nummer und Handbuch | 1963 1201046 120 |
Anwendungen & Verwendung
Beschreibung
Helium is a colorless, odorless, and tasteless monoatomic gas with an atomic weight of 4, a density of 1.78 g per 1 at 0°C and 1 atmosphere pressure, and an aqueous solubility of 0.97 mL per 100 mL at 50°C. The Bunsen solubility coefficient (the volume, in mL, of gas at standard conditions dissolved per mL of liquid).of helium at 38°C is 0.0086 in water, and 0.015 in olive oil. After hydrogen, helium is the most abundant element in the universe; these elements are believed to represent 76 and 23 percent, respectively, of all matter in the universe. The earth’s atmosphere, however, contains only 5 ppm of helium. Mineral gases from wells contain higher concentrations and serve as the principal source for industrial production. Helium is chemically very inert; it has a weak tendency to combine with other elements such as fluorine. It is usually marketed as compressed gas, with the USP grade containing not less than 99 percent helium.The largest biological use of helium is the replacement for nitrogen in synthetic breathing gas mixtures for divers and others working under high pressure conditions. The low solubility in body fluids compared to nitrogen decreases the danger of bends on depressurizing.
Verwenden
Helium is used as an inert gas shield in arc welding, as a lifting gas for lighter-than-air aircraft, and as a gaseous cooling medium in nuclear reactors. It is also used to provide a protective atmosphere for growing germanium and silicon crystals for transistors, to provide a protective atmosphere in the production of such reactive metals as titanium and zirconium, to fill cold-weather fluorescent lamps, to trace leaks in refrigeration and other closed systems, and to fill neutron and gas thermometers. Its thermal conductivity makes it an important gas for lasers and fiber optic production. It is used extensively in chromatography due to its inertness and high thermal conductivity. It is used in cryogenic research such as for superconductivity. In mixtures with oxygen, it has medical and diving applications. Radioactive mixtures of helium with krypton are available to users licensed by the Nuclear Regulatory Commission. NASA uses helium for purging and pressurizing the liquid hydrogen tanks of spacecraft because it is the only element that remains a gas in the extreme cold necessary to maintain the liquid hydrogen fuel used in many rockets and the Space Shuttle. Liquid helium is used for cooling superconductive magnets, used in magnetic resonance imaging, and in magnetic separation.