Molecular Formula | Ar |
Molar Mass | 39.95 |
Density | 1.784(0℃) |
Melting Point | -189.2°C(lit.) |
Boling Point | -185.7°C(lit.) |
Water Solubility | 33.6mL/1000g H2O (20°C) [KIR78]; Henry’s law constants, k×10?4: 3.974 (25.0°C), 5.359 (65.1°C), 5.342 (91.1°C), 3.812 (222.7°C), 2.541 (267.3°C), 1.870 (287.9°C) [POT78] |
Vapor Presure | 343000mmHg at 25°C |
Vapor Density | 1.38 (21 °C, vs air) |
Appearance | colorless gas |
Merck | 13,788 |
Stability | Stable. Inert. |
Physical and Chemical Properties | A rare gas with the highest content in air. Colorless, tasteless, odorless. melting point -189.2 ℃ boiling point -185.7 ℃ relative density 1.784(0 ℃) soluble in water, the solubility is 5.6g/cm3 water at 0 °c. Also soluble in ethanol. |
Use | Commonly used as inert protective gas, filled with various types of bulbs |
Safety Description | 38 - In case of insufficient ventilation, wear suitable respiratory equipment. |
UN IDs | UN 1006 2.2 |
WGK Germany | - |
RTECS | CF2300000 |
FLUKA BRAND F CODES | 4.5-31 |
Hazard Class | 2.2 |
colorless, tasteless, odorless, non-toxic inert gas, chemical properties are very inactive. The gas relative density was 21.1 at 101 °c and 1.38.3kPa. The gas density is 1-21.1. m-3 (101 ° C, 185.9. 3kPa), and the liquid density is 101kg.m-3 (-° C,. 3kPa). Boiling point -185.9 °c. Melting Point -189.2 °c. Critical temperature -122.3C, critical pressure 4. 893MPa. Soluble in organic solvents. Not burning, non-toxic, but the human body is easy to asphyxia inhalation. Non-corrosive.
In case of high fever, the internal pressure of the container increases, and there is a risk of cracking and explosion.
argon is extracted by air separation, that is, the liquefied air is rectified to obtain crude argon, and the crude argon can be further purified to obtain high purity argon.
high purity argon is used in the semiconductor industry as a protective gas for the production of high purity silicon and germanium crystals; Can be used as an inert gas for system cleaning, shielding and pressurization; In chemical vapor deposition, sputtering and annealing and other processes have applications. High purity argon can be used as a carrier gas for chromatography, and can also be used as a dilution gas for mixed gases in large scale integrated circuits. Argon is widely used for filling arc lamps, fluorescent lamps and electron tubes; Welding shielding gas; Used as shielding gas in the production of titanium, cobalt and other active metals; In black metallurgy, argon is used for blowing special steel, in order to improve the quality of steel, especially the consumption of large amounts of argon in the manufacture of stainless steel.
non-toxic, is a kind of asphyxiating gas, high concentration, the oxygen partial pressure is reduced and suffocation, argon concentration of more than 50%, causing serious symptoms; More than 75%, death can occur within minutes. When the concentration of argon in the air is increased, the breathing is accelerated, and the concentration is not concentrated, so that death occurs. Avoid inhalation of high concentrations. Access to tanks, restricted spaces or other areas of high concentration should be monitored. Liquid Argon can cause skin frostbite; Eye contact can cause inflammation. Store in a cool, ventilated warehouse. Keep away from fire and heat source. Storage temperature should not exceed 30 ℃. Should be stored separately from the easy (possibly) combustible, not mixed storage.
NIST chemical information | information provided by: webbook.nist.gov (external link) |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Introduction | the chemical symbol of Argon element is Ar, the atomic order is 18, located in group 18 of the periodic table, it is a rare gas. Argon accounts for 0.934% of the atmospheric volume (9340 ppmv), is the third largest gas in the Earth's atmosphere, is more than two times the water vapor (an average of about 4000 ppmv, but the change is very large), carbon dioxide (400 ppmv) 23 times as much as neon (18 ppmv) more than 500 times. Argon is the most abundant inert element in the Earth's crust, accounting for 0.00015% of the Earth's crust. There are 14 known isotopes of argon, including argon 33 to argon 46. Most of the argon element in the Earth's atmosphere is argon -40 (from the decay of potassium -40 in the Earth's crust). Argon -36 is the most common isotope of argon in the universe, because it is the most easily produced by supernovae fusion. |
History of discovery | argon (from the Greek version), the nomenclature is referenced to its chemical activity. The chemical properties of this first discovered noble gas were impressive to the nomenclature. In 1785, Henry cvendish suspected that rare gases were part of the atmosphere. In 1849, at University College London, John Strat, third-generation barons Rayleigh and William ramzil, through the removal of oxygen, carbon dioxide, water and nitrogen in clean air samples, the argon was isolated from the air for the first time. They have confirmed that the nitrogen generated from chemical compounds is 0.5% lighter than the nitrogen in the atmosphere, with slight differences, but it is important enough to attract their attention for several months. They concluded that there was another gas in the air mixed with nitrogen. Argon was also serendipitously discovered in 1882 by the study of H. F. Newall and Watt Nohr hertley. They found new emission spectra that did not match the elements already known at the time. Until 1957, the chemical symbol of argon was "A", which was later changed to "Ar" until now. |
Source | argon is the 56th most abundant element on Earth. It is the most abundant of all noble gases in the atmosphere. In fact, the only source of argon is the atmosphere, where the volume of argon is slightly less than 1%. |
Application | argon is used when an inert atmosphere is required. It can be used alone or mixed with other inert gases to fill light bulbs, fluorescent tubes, lasers, etc. By replacing the oxygen in an incandescent bulb, the oxygen can be prevented from corroding the filaments of the bulb. It is also used as a non-oxidizing gas during welding and as a decarburizing agent for steel, and as an inert atmosphere for growing semiconductor crystals therein. |
preparation | there is more than one preparation method of argon. The most common is by fractionation of liquid air. Argon is a by-product of this large-scale commercial process. During the fractionation, argon is boiled at a fixed temperature. It is then collected and purified by charcoal to filter out helium and other gases, thereby producing a significant amount of argon. |
Health effects | argon is non-toxic, but acts as a asphyxiating gas, it can asphyxiate by replacing oxygen in the lungs. The vapor of argon may cause dizziness and even suffocation. |
solubility in water (g/100ml) | grams dissolved per 100ml of water: 4G/20 ℃ |
identification test | when a burning piece of wood is placed in a vertical tube filled with argon, it should be extinguished. |
toxicity | argon itself is non-toxic, but there is a high concentration of argon in the air, that is, a suffocation effect. |
purpose | commonly used as inert protective gas, filled with various types of bulbs used as rare metal smelting protective gas, carrier gas, Zero Point gas, standard gas, calibration gas for chemical, metallurgical, gas chromatography and other instruments, can also be used for semiconductor device manufacturing used as filling gas in the bulb industry mainly used for metal welding and cutting, such as for light metals, the welding and cutting of stainless steel or special alloy steel is the most widely used argon arc welding in the mist atmosphere of argon. For semiconductor refining, the industry commonly used 5% hydrogen and 95% argon gas mixture as silicon semiconductor refining protective atmosphere. For metal smelting, in the smelting of titanium, zirconium and other metals, the need for argon and other inert protective atmosphere for reduction reaction, but also used as a degassing agent for smelting special steel. In the application of plasma, the mixture of argon and hydrogen as plasma can be used in magnetic fluid power generation, and the application of electric light source. inert gas for packaging. |
production method | the argon-containing fraction extracted from the air for oxygen generation is made into crude argon through an argon column, oxygen in crude argon was removed by re-hydrogenation, and 99.99% ~ 99.999% high purity argon was obtained after rectification and denitrification. The extraction of argon from the tail gas of ammonia synthesis can be divided into two categories: the low temperature separation of the tail gas discharged after synthesis and the liquid nitrogen washing and low temperature separation of the synthesis gas before entering the synthesis column. In low temperature separation process, 99.999% pure argon can be obtained by purifying, partially condensing or rectifying the raw material gas to separate hydrogen, nitrogen and methane, and separating the mixture of argon and nitrogen. |
category | hazardous gas |
Acute toxicity | asphyxial toxicity only |
explosive hazard characteristics | cylinder explosion at high temperature |
flammability hazard characteristics | non-flammable, non-toxic, but asphyxiating |
storage and transportation characteristics | warehouse ventilation and low temperature drying; Light loading and light unloading |
extinguishing agent | Water |
DOT Classification | 2.2 (Nonflammable gas) |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |