Project Work on Gases and their Applications Sl 30th April 2012 Contents no. Page no. 1 Introduction 2 2 Hydrogen gas, its preparation, properties and applications 3-4 3 Oxygen gas, its preparation, properties and applications 5-7 4 Nitrogen gasits preparation, properties and applications 8-9 5 Nitrogen dioxide its preparation, properties and applications 10-11 6 Nitrous oxide, its preparation, properties and applications 11-12 7 Carbon dioxide, its preparation, properties and applications 12-14 8 Carbon monoxide, its preparation, properties and applications 14-15 9 Preparation, properties and applications of hydrocarbon gases 15-22 10 Preparation, properties and applications of Inert gases 22-27 11 Chlorine, its preparation, properties and applications 27-30 12 Fluorine, its preparation, properties and applications 30-31 13 Applications of gases in Bhutan 32 14 Conclusion 33 15 References 34-35 Page 1 of 35 Project Work on Gases and their Applications 30th April 2012 Introduction Chemistry is the science of matter. Matter basically includes solid, liquid and gases. And gases are one of the three states of matter. Gases can either be in free-states or in combined states. Some are very paramount for the survival of every organism while few gases are harmful. Many are useful while few are not. By taking the advantages of its utility, mankind manufacture for their consumption and as life elixirs in the hospital, industries, etc. Basically, this booklet of project comprises all the gases in elementary form as well as compound from. Moreover, their industrial manufacturing processes, properties both physical and chemical properties, applications as generally and few in the Bhutan are also included. As a chemist and chemistry teacher it is important to know the processes of manufacturing each gas besides availability of facilities in our country. Knowing the properties both physical and chemical properties too are vital as to distinguish each gas. Of all, the applications of each gas in general and particularly in Bhutan are also vital. For example, carbon dioxide is used for the manufacture of the fizzy drinks in Pasakha. There are so many uses of each gas in everyday life and have been using in many industries worldwide and in Bhutan too. Page 2 of 35 Project Work on Gases and their Applications 30th April 2012 Hydrogen gas Industrial preparation a) Electrolysis of acidulated water Water is acidified with sulphuric acid to conduct electricity. Heavy current is passed through acidulated water. It liberates hydrogen gas at cathode and oxygen gas at anode. Process is applied where the electricity is cheap and it is 99.9% pure 2H2O 2H2 + O2 b) From water gas (Bosch Process) Water gas is mixed with double the volume of steam and passed through catalyst at 5000 C. Fe2O3 / Cr2O3 [CO + H2] + H2O CO2 + H2 5000 C The water gas is passed through water where carbon dioxide is absorbed. Then hydrogen gas passed through ammoniac cuprous chloride to remove carbon monoxide. Finally hydrogen gas is passed through calcium chloride to remove moisture (water vapor). Properties of hydrogen gas a) Physical properties 1. It is colorless, odorless and tasteless. 2. It has low density (lightest gas) 3. It is insoluble in water. 4. It get liquefied at -2400C at 20atm. 5. It is good conductor of heat 6. It is readily absorbed by metals B) Chemical properties 1. It is neutral to litmus paper 2. It is combustible and inflammable gas Page 3 of 35 Project Work on Gases and their Applications 30th April 2012 3. Reaction of hydrogen with non – metal a. With chlorine- hydrogen combines with chlorine slowly in presence of diffused sunlight to form hydrochloric acid. H2 + Cl2 2HCl b. With nitrogen- when the mixture of nitrogen and hydrogen gas in ratio 1:3 is compressed to 200-500 atm and passed over heated iron catalyst, containing molybdenum (promoter) at 450-5000C, combine to form ammonia. N2 + H2 2NH3 c. With sulphur- when dry hydrogen is bubbled through molten sulphur, it reacts with sulphur to form hydrogen sulphide which smells like rotten egg. H2 + S H2 S 4. Reaction with metals. 2Na + H2 2NaH [NaH + H2O 2K + H2 2KI [KH + H2O NaOH + H2] KOH + H2] 5. Action with metal oxides (reducing property). CuO + H2 Cu + H2O PbO + H2 Pb + H2O Fe2O3 + 3H2 2Fe + 3H2O Uses of hydrogen 1. As a fuel. Because of its high heat of combustion, hydrogen is used as an industrial fuel. 2. Oxy-hydrogen torch. A mixture of hydrogen and oxygen when burnt in a specially designed apparatus called oxy-hydrogen torch produces temperatures around 25000C which is used for cutting and welding of metals. 3. Atomic-hydrogen torch. 4. Synthesis of compounds. N2 + 3H2 CO + 2H2 Page 4 of 35 2NH3; H2 + Cl2 CH3OH 2HCl Project Work on Gases and their Applications 30th April 2012 Oxygen Industrial preparation a) Fractional distillation of liquid air The air is passed through fine filters to remove dusts. The air is cooled to about -800 C to remove water vapor and carbon dioxide as solid. Cold air is compressed to about 100atm and this warms air. Then air is passed through cool pipes to cool down. The process of compression followed by expansion is repeated until the air reaches a temperature below -2000 C and air gets liquefied. Liquid air is fractionally distilled and separated base on their boiling points. The liquid air is slowly warm up and other gases vaporized and liquid oxygen remain at the bottom of fractionating column. It change to gas and then filled in compressed state in steel cylinders. b) Electrolysis of water. Water is acidified with sulphuric acid to conduct electricity. It is taken in Hoffman’s Voltameter. Heavy current is passed through acidulated water. It liberates hydrogen gas at cathode and oxygen gas at anode. Process is applied where the electricity is cheap and it is 99.9% pure 2H2O 2H2 + O2 Propertied of oxygen gas a) Physical properties 1. It colorless, odorless & non-poisonous gas 2. It is slightly heavier than gas 3. It is slightly soluble in water 4. It liquefied at normal pressure at -1860C and solidifies at -2180C. b) Chemical properties 1. It is neutral to litmus gas 2. It is non-combustible substance but help other substance to burn. 3. Oxygen is oxidizing agent and it oxidize all metals (except Ag & Au) and non-metals (except halogens) to form their oxides. Page 5 of 35 30th April 2012 Project Work on Gases and their Applications a) Non – metals 1. With hydrogen – pure hydrogen burns in presence of oxygen to produce the water 2H2 + O2 2H2O 2. With carbon – red hot charcoal is put in a jar containing oxygen to produce carbon dioxide C + O2 CO2 3. With sulphur – when burning sulphur is introduce in the jar containing oxygen, it burns brightly to produce sulphur dioxide S +O2 SO2 4. With phosphorus – when a yellow phosphorus is warmed in a deflagrating spoon and then lowered in a jar containing oxygen, it burns to produce phosphorus pentaoxide 4P + 5O2 2P2O5 b) Metals 1. With sodium – sodium burns in presence of oxygen to produce sodium oxide 4Na + O2 2Na2O 2Na + O2 Na2O2 2. With calcium – when burning Ca is introduced in the jar of oxygen, it burns to form white ash of calcium oxide. Ca + O2 2CaO 3. With magnesium – when burning magnesium is introduced in the jar of oxygen, it burns to form white powder of magnesium oxide. 2Mg + O2 2MgO 4. With iron – when hot iron is introduced in a jar of oxygen, it produces sparks and form the tri-ferric tetroxide 3Fe + O2 Page 6 of 35 Fe3O4 30th April 2012 Project Work on Gases and their Applications c) Oxidation of lower oxides to higher oxides 1. Nitric oxides combines with oxygen at room temperature to form nitrogen dioxide 2NO + O2 2NO2 2. Carbon monoxides burn in oxygen to form carbon dioxide 2CO + O2 2CO2 3. Sulphur dioxide on heating with oxygen at 450 degree centigrade in presence of catalyst form sulphur trioxide. 2SO2 + O2 2SO3 4. Ammonia gas burns with pale flame in an atmosphere of oxygen to form nitrogen gas and steam 4NH3 + 3O2 2N2 + 6H2O 5. Iron (II) oxides heating in presence of oxygen form iron (III) oxides 4FeO + O2 2Fe2O3 Uses of oxygen Oxygen has number of uses in our daily life and industry as described below: a. Industrial uses 1. In the iron and steel industry. 2. In chemical industries 3. For welding and cutting metals 4. For blasting of rocks 5. As a rocket fuel. b. Uses in medicines 1. Artificial respiration 2. Carbogen 3. Anaesthesia. Page 7 of 35 Project Work on Gases and their Applications 30th April 2012 Nitrogen gas Industrial preparation a) Fractional distillation of liquid air The air is passed through fine filters to remove dusts. The air is cooled to about -800 C to remove water vapor and carbon dioxide as solid. Cold air is compressed to about 100atm and this warms air. Then air is passed through cool pipes to cool down. The process of compression followed by expansion is repeated until the air reaches a temperature below -2000 C and air gets liquefied. Liquid air is fractionally distilled and separated base on their boiling points. The liquid air is slowly warm up and other gases vaporized. At -1950 C nitrogen vaporizes and nitrogen gas is collected. Properties of nitrogen gas Physical properties 1. It is colorless, odorless & tasteless gas 2. It is slightly lighter than air 3. It s slightly soluble in water 4. It can be liquefied at -1950 C and solidifies at – 210.50C 5. It is non-poisonous gas Chemical properties 1. It s chemically inert gas at room temperature 2. It is neutral to litmus 3. It is neither combustible nor supporter of combustion 4. Reaction with non-metals a) Hydrogen – b) N2 + 3H2 2NH3 c) Oxygen N2 + O2 Page 8 of 35 2NO Project Work on Gases and their Applications 30th April 2012 5. Reaction with metals: 6Li + N2 2Li3N 3Ca + N2 Ca3N2 Ca3N2 + 6H2O 3Ca(OH)2 + 2NH3 2Al + N2 2AlN AlN + 3H2O Al(OH)3 + NH3 3Mg + N2 Mg3N2 Mg3N2 + 6H2O 3Mg(OH)3 + 2NH3 6. Reaction with chemical compounds Al2O3 + N + 3C CaC2 + N 2AlN + 3CO CaNCN + C Uses of nitrogen The major uses of nitrogen are based on the three characteristics of nitrogen as follows: a. Uses based on inert nature 1. Dilutes the effect of oxygen in the air. 2. Used in high temperature thermometers 3. Canned food stuffs 4. Electric bulbs 5. In industries 6. In welding b. Uses based on low boiling point 1. As refrigerant for freezing food stuff 2. Liquid nitrogen is used to store living cells and biologically important tissues. c. Uses based on nitrogen being a constituent of proteins 1. Used by the plants for the protein synthesis. 2. Used for the manufacture of fertilizers. Page 9 of 35 Project Work on Gases and their Applications 30th April 2012 Nitrogen dioxide Preparation Nitrogen dioxide is produced by following method: a) Oxidation of nitric oxide by air (oxygen) 2 NO + O2 2 NO2 b) The thermal decomposition of some metal nitrates also liberate nitrogen oxide 2 PbO + 4 NO2 + O2 2 Pb(NO3)2 Properties of nitrogen dioxide Physical properties It is a reddish brown gas. It has pungent smell. It is heavier than air (denser than air) The substance is corrosive to the skin and the respiratory tract. Boiling point 21.2°C and melting point is -11.2°C Chemical properties 1. Reaction with water 2NO2 (g) + H2O (l) HNO2(aq) + HNO3(aq) 2. Reaction with alkalis 2KOH (aq) + 2NO2 (g) KNO3(aq) + KNO2(aq) + H2O(l) 3. Action of heat. 2NO2 (g) Page 10 of 35 2NO (g) + O2 (g) Project Work on Gases and their Applications 30th April 2012 4. Reduction by reducing agent Nitrogen dioxide can also be reduced to lower oxide or nitrogen by reducing agents. Heated copper reduce nitrogen dioxide to nitrogen gas and copper will form copper (II) oxide (CuO) and nitrogen gas. 4Cu(s) + 2NO2 (g) 4CuO(s) + N2 (g) Applications/Uses Nitrogen Dioxide is used as rocket fuel, a flour bleaching agent Used in increasing the wet strength of paper Nitrogen is used for the production of ammonia, nitric acid and fertilizers. Nitrous oxide (laughing gas) Industrial preparation Nitrous oxide is most commonly prepared by careful heating of ammonium nitrate, which decomposes into nitrous oxide and water vapor. NH4NO3 (s) → 2 H2O (g) + N2O (g) Physical properties It is 1 1/2 times denser than air, It is colorless, tasteless, and has a slightly sweet odor It’s boiling point (°F) is -128.3and melting point (°F) is -131 Chemical properties It decomposes to produce nitrogen and oxygen gas. 2N2O(g) → 2N2(g) + O2(g) Reaction with sulphur S(s) + 2N2O(g) → SO2(g) + 2N2(g) Reaction with magnesium Mg(s) + N2O(g) → MgO(s) + N2(g) Reaction with copper Page 11 of 35 Project Work on Gases and their Applications 30th April 2012 Cu(s) + N2O(g) → N2(g) + CuO(s) Applications/Uses Nitrous oxide can be used as an oxidizer in a rocket motor In vehicle racing, nitrous allows the engine to burn more fuel by providing more oxygen than air alone, resulting in a more powerful combustion The gas is approved for use as a food additive nitrous oxide has been used for anesthesia in dentistry use in the recreation CARBON DIOXIDE Industrial Preparation CALCIUM + HYDROCHLORIC = CALCIUM + WATER + CARBON CARBONATE ACID CHLORIDE DIOXIDE (MARBLE) CaCO3 + Page 12 of 35 2HCl = CaCl2 + H2O + CO2 Project Work on Gases and their Applications 30th April 2012 Physical Properties of CO2 CO2 gas has a slightly irritating odor, is colorless and heavier than air. It cannot sustain life. It freezes at -78.5 °C to form carbon dioxide snow. Liquid density : 1032 kg/m3 · Liquid/gas equivalent: 845 vol/vol Colorless Inert, non flammable Chemical Properties of CO2 In an aqueous solution it forms carbonic acid. Latent heat of vaporization : 571.08 kJ/kg Vapor pressure : 58.5 bar It will not burn or support combustion. Applications/Uses In the chemical industry, carbon dioxide is mainly consumed as an ingredient in the production of urea and methanol. . Carbon dioxide is used to produce carbonated soft drinks and soda water. Carbon dioxide in the form of dry ice is often used in the wine making process to cool down bunches of grapes quickly after picking to help prevent spontaneous fermentation by wild yeasts. Carbon dioxide extinguishes flames, and some fire extinguishers, especially those designed for electrical fires; contain liquid carbon dioxide under pressure. Refrigerant Liquid and solid carbon dioxide are important refrigerants, especially in the food industry, where they are employed during the transportation and storage of ice cream and other frozen foods. Solid carbon dioxide is called "dry ice" and is used for small shipments where refrigeration equipment is not practical. Page 13 of 35 Project Work on Gases and their Applications 30th April 2012 Carbon monoxide Industrial production A major industrial source of CO is producer gas, a mixture containing mostly carbon monoxide and nitrogen, formed by combustion of carbon in air at high temperature when there is an excess of carbon. In an oven, air is passed through a bed of coke. The initially produced CO2 equilibrates with the remaining hot carbon to give CO. The reaction of O2 with carbon to give CO is described as the Boudouard equilibrium. Above 800 °C, CO is the predominant product: O2 + 2 C → 2 CO (ΔH = −221 kJ/mol) Another source is "water gas", a mixture of hydrogen and carbon monoxide produced through endothermic reaction of steam and carbon: H2O + C → H2 + CO (ΔH = +131 kJ/mol) Physical properties It is a colourless, odourless, neutral, gaseous oxide, which is highly poisonous, Is sparingly soluble in water, but is soluble in ethanol and in benzene. It has Melting Point : -199 degC Boiling Point : -91.5 degC Relative density : 1.25 Chemical properties is a flammable and highly toxic gas, is a neutral oxide which burns in air to give carbon dioxide, is a good reducing agent, and is used for that purpose in industry, CuO + CO ==> And, is an important industrial gas, which is widely used as a fuel. Page 14 of 35 Cu + CO2 Project Work on Gases and their Applications 30th April 2012 Applications/Uses Carbon monoxide is an industrial gas. Large quantities of aldehydes are produced by the hydroformylation reaction of alkenes, carbon monoxide, and H2. It is also used for the industrial production of acetic acid. Methane gas Industrial preparation Methane gas is prepared on large scale from natural gas by liquefaction. We also prepared by following processes (a) From carbon monoxide: A mixture of carbon monoxide and hydrogen is passed over a catalyst containing nickel and carbon at when methane is formed. Bi + C CO + 3 H2 ————→ CH4 + H2O 250o C (b) Synthesis: By striking an electric arc between carbon electrodes in an atmosphere of hydrogen at 1200oC, methane is formed. 1200o C C + 2 H2 ————→ CH4 By passing a mixture of hydrogen sulphide and carbon disulphide vapor through red hot copper, methane is formed. High temperature CS2 + 2H2S + 8Cu ————→ CH4 + 4Cu2S Page 15 of 35 Project Work on Gases and their Applications 30th April 2012 Properties of methane (marsh gas) Physical properties 1. Methane gas is colorless, odorless & tasteless gas 2. Methane gas has density lighter than air. 3. Methane becomes liquid below 112 K and solidifies at 90.5 K. 4. This gas is slightly soluble in water but soluble in organic solvents. Chemical properties 1. It reacts with oxygen to give huge amount of energy CH4 + 2O2 CO2 + 2H2O 2. It reacts with chlorine gas CH4 + 5Cl2 CH3Cl+ CH2Cl2+ CHCl3+ CCl4 3. It decomposes to acetylene at high temperature 4. 2CH4 C2H2+3H2 Applications/Uses Methane is useful in the testing of gas appliances which are to be used for natural gas areas. It is one of the raw materials used in the production of ethanol, methyl chloride, ethylene chloride, and is also used to produce ammonia and acetylene. High purity methane is burned to form a high quality carbon black which is used in a variety of electronic components. Gas is widely used as a fuel in homes, commercial establishments, and factories Page 16 of 35 Project Work on Gases and their Applications 30th April 2012 Acetylene Industrial preparation The industrial preparation of acetylene was discover by the Friedrich Wohler in 1862. Acetylene is produce by hydrolysis of water on calcium carbide. CaC2 + 2H2O Ca (OH)2 + C2H2 Physical properties It is a colorless and flammable gas. It has a ginger like odor (100% pure is odorless) Boiling point is -120.60 F Melting point is -113.00 F Chemical properties Acetylene can be decomposed to its elements with the liberation of heat Together with air it forms an explosive mixture Thermal decomposition produces carbon monoxide that is poisonous It possesses a reactive triple bond between carbon and carbon. it reacts with strong bases to form acetylide salts Applications/Uses In chemical synthesis As Oxyacetylene gas welding and cutting due to the high temperature of the flame. Propane Preparation Propane is produced as a by-product of two other processes, natural gas processing and petroleum refining. The processing of natural gas involves removal of butane, propane, and large amounts of ethane from the raw gas, in order to prevent condensation of these volatiles in natural gas pipelines. Additionally, oil refineries produce some propane as a by-product of cracking petroleum into gasoline or heating oil. Page 17 of 35 Project Work on Gases and their Applications 30th April 2012 Physical properties Propane is heavier than air. Propane is a liquid at -50°F and boils at -44°F Liquid propane will flash to a vapor at atmospheric pressure and appears white due to moisture condensing from the air Propane is non-toxic . Chemical properties In the presence of excess oxygen, propane burns to form water and carbon dioxide. C3H8 + 5 O2 3 CO2 + 4 H2O + heat Incomplete burning of the propane yields water, carbon monoxide, carbon dioxide and carbon 2 C3H8 + 7 O2 2 CO2 + 2 CO + 2 C + 8 H2O + heat Applications/Uses Propane is also being used increasingly for vehicle fuels As a gas absorption refrigerator As domestic and industrial fuel Propane is the primary fuel for hot air balloons. It is used in semiconductor manufacture to deposit silicon carbide Page 18 of 35 Project Work on Gases and their Applications 30th April 2012 Ammonia Industrial Preparation Haber process It is prepared at 300-3500C and 150-250bar. The gas is passed over beds of catalyst with cooling between each pass to maintain a reasonable equilibrium constant. On each pass of gases, 15% of gases are converted to ammonia and unused gas is recycled. N2 (g) + 3 H2 (g) 2 NH3 (g) Physical properties Ammonia is extremely soluble in water and is frequently used as a water solution called aqua ammonia. anhydrous ammonia is a clear, colorless liquid or gas, free from visible impurities It is 99.95 percent pure ammonia. Anhydrous ammonia is nonflammable. Chemical properties Ammonia, especially in the presence of moisture, reacts with and corrodes copper, zinc, and many alloys. Ammonia will combine with mercury to form a fulminate which is an unstable explosive compound. Applications/Uses Most of the ammonia used in the world is used in fertilizer either in salt or liquid form. Almost all synthetically derived nitrogen is made from ammonia. Household ammonia is used as a surface cleaner in a diluted form. It is used in geothermal power plants in an ammonia-water mixture that is boiled. Page 19 of 35 Project Work on Gases and their Applications 30th April 2012 Ethane Preparation Ethane is mostly separated from methane by liquefying it at cryogenic temperatures. In this process, chilled gas expands through a turbine. As the gas expands, its temperature drops to about 100°C. At this low temperature, gaseous methane can be separated from the liquefied ethane and heavier hydrocarbons by distillation. Further distillation then separates ethane from the propane and heavier hydrocarbons. Physical properties Odorless and colorless gas at STP The melting point of ethane is -181.76° C and boiling point is -88.6° C It is soluble in polar solvents like water. Chemical properties Incomplete or partial combustion of the gas leads to the production of single-carbon compounds like carbon monoxide and formaldehyde. Additional trivial products produced during ethane's partial combustion are acetaldehyde, methanol, ethanol, and methane Applications/Uses Ethane is primarily used for the production of ethylene through the process of steamcracking Use as a fuel Ethane can be used as a refrigerant in cryogenic refrigeration systems. Page 20 of 35 Project Work on Gases and their Applications 30th April 2012 Ethylene Preparation Ethylene is produced in the petrochemical industry by steam cracking. In this process, gaseous or light liquid hydrocarbons are heated to 750-950 °C, inducing numerous free radical reactions followed by immediate quench to stop these reactions. This process converts large hydrocarbons into smaller ones and make it unsaturated hydrocarbon. Ethylene is separated from complex mixture by repeated compression and distillation. Heavier feed stocks require two quench towers downstream of the cracking furnaces to process water. Physical properties colorless gas at room temperature and pressure Melting point -169oC and Boiling point -104oC slightly sweet smell flammable non-polar molecule soluble in non-polar solvents & insoluble in polar solvents like water Chemical properties Action of bromine CH2=CH2 + Br2 CH2BrCH2Br (1, 2-dibromoethane) Addition of Chlorine CH2=CH2 + Cl2 AlCl3 CH2ClCH2Cl (1,2-dichloroethane) Addition of Hydrogen bromide CH2=CH2 + HBr Page 21 of 35 CH3CH2Br (bromoethane) Project Work on Gases and their Applications 30th April 2012 Addition of Hydrogen CH2=CH2 + H2 CH3CH3 (ethane) Addition of Water CH2=CH2 + H2O H3PO4 CH3CH2OH (ethanol) Combustion CH2=CH2 + 3O2 2CO2 + 2H2O Uses Production of Polythene Production of Industrial Alcohol Ethylene is also used as a plant hormone to control the ripening and colour development of fruit Helium Industrial Preparation Helium is separated by liquefying the other gases present in the natural gas; it is then either further purified or stored for later purification and use. Some helium is extracted directly from the atmosphere. It is the end product of energy-releasing fusion processes in stars. Properties The nucleus of the helium-4 atom is identical with an alpha particle. Helium is the least reactive noble gas after neon and thus the second least reactive of all. Page 22 of 35 Project Work on Gases and their Applications 30th April 2012 Uses/applications A mixture of helium and oxygen is often supplied as a breathing mixture for deep-sea divers and caisson workers. Helium can also be used in electric arc welding, in growing crystals of silicon and germanium for semiconductors, and in refining titanium and zirconium metals.. Neon Industrial Preparation Fractional distillation from liquid air. Air is liquified, and as the temperature is raised slowly, different gases come out of the mix based on their boiling point. Properties A colorless, odorless, nonflammable, inert Gas. Applications/applications Used as a buffer gas or the active medium in various types of gas lasers such as helium/neon, excimer or copper vapor lasers. Used as a carrier gas in chromatography applications. Liquid neon is used in the following: liquid hydrogen replacement studies, cryo-sorption and cryo-pumping, nuclear particle detection in bubble chambers, and in lung diffusion gas Argon Industrial Preparation Argon is produced industrially by the fractional distillation of liquid air in a cryogenic air separation unit; a process that separates liquid nitrogen, which boils at 77.3 K, from argon, which boils at 87.3 K and liquid oxygen, which boils at 90.2 K. Page 23 of 35 Project Work on Gases and their Applications 30th April 2012 Properties (Physical and Chemical properties) Argon is colorless, odorless, and nontoxic as a solid, liquid, and gas. Argon is chemically inert under most conditions and forms no confirmed stable compounds at normal temperature. Applications/Uses Argon is mostly used as an inert shielding gas in welding and other high-temperature industrial processes where ordinarily non-reactive substances become reactive. Argon gas also has uses in incandescent and fluorescent lighting, and other types of gas discharge tubes. Argon is sometimes used for extinguishing fires where damage to equipment is to be avoided. Cryosurgery procedures such as cryoablation use liquefied argon to destroy cancer cells. Incandescent lights are filled with argon, to preserve the filaments at high temperature from oxidation. Krypton Industrial Preparation Making liquid air 1 .Air is first passed through filters to remove particulate matter such as dust. The clean air is then exposed to an alkali which removes water and carbon dioxide. 2. The clean, dry air is compressed under high pressure. Iit is then cooled by refrigeration. 3. The cooled, compressed air passes through coils winding through an empty chamber. A portion of the air, which is compressed to a pressure about two hundred times greater than normal, is allowed to expand into the chamber. This sudden expansion absorbs heat from the coils, cooling the compressed air. Page 24 of 35 Project Work on Gases and their Applications 30th April 2012 Separating the gases 4. Gases with very low boiling points are not transformed into liquids and can be removed from the others directly. 5. A process known as fractional distillation separates the various elements found in liquid air. 6. The liquid air is allowed to warm slowly. As the temperature increases the substances with the lowest boiling points become gases and can be removed from the remaining liquid. Krypton and xenon have higher boiling points and remain in the liquid state. 7. The liquid krypton and xenon are absorbed onto silica gel or onto activated charcoal. They are then once again subjected to fractional distillation. The liquid mixture is warmed slowly until the krypton is transformed into a gas. The xenon has a somewhat higher boiling point and remains behind as a liquid. 8. The krypton is purified by passing it over hot titanium metal. Properties Under normal conditions, krypton is a colorless, tasteless, odorless gas. Its density at normal temperature and pressure is about 0.5 oz per gallon. At extremely low temperatures, krypton may exist as a liquid or a solid. Its B.P -243.81° F and F.B is -251.27° F Applications/Uses Krypton is used with argon in fluorescent lights to improve their brightness And with nitrogen in incandescent lights to extend their lifetime. It is also used in flashbulbs to produce a very bright light and For use in high-speed photography. Page 25 of 35 30th April 2012 Project Work on Gases and their Applications Xenon Industrial Preparation Xenon is obtained commercially as a byproduct of the separation of air into oxygen and nitrogen. After this separation fractional distillation is applied in a double-column plant, the liquid oxygen produced will contain small quantities of krypton and xenon. By additional fractional distillation steps, the liquid oxygen may be enriched to contain 0.1–0.2% of a krypton/xenon mixture, which is extracted either via adsorption onto silica gel or by distillation. Finally, the krypton/xenon mixture may be separated into krypton and xenon via distillation Properties Colorless gas, exhibiting a blue glow when placed in a high voltage electric field. At standard temperature and pressure, pure xenon gas has a density of 5.761 kg/m3 Applications/Uses Xenon is used in light-emitting devices called xenon flash lamps, which are used in photographic flashes and stroboscopic lamps. Xenon has been used as a general anesthetic. Xenon is finding application in treating brain injuries. Gamma emission from the radioisotope 133 Xe of xenon can be used to image the heart, lungs, and brain. Radon Industrial Preparation Radon is obtained as a by-product of uraniferous ores processing after transferring into 1% solutions of hydrochloric or hydrobromic acids. Radon is produced by a solution of radium-226 . Radium-226 decays by alpha-particle emission also produces radon which collects over samples of radium-226 at a rate of about 1 mm3/day per gram of radium. Page 26 of 35 Project Work on Gases and their Applications 30th April 2012 Physical properties Radon is a colorless and odorless gas, and therefore not detectable by human senses alone. At standard temperature and pressure its density of 9.73 kg/m3. Radon is one of the densest gases at room temperature and is the densest of the noble gases. its freezing point of 202 K. Chemical properties Radon is sparingly soluble in water, but more soluble than lighter noble gases. Radon is appreciably more soluble in organic liquids than in water. Radon can be oxidized by a few powerful oxidizing agents such as fluorine, thus forming radon fluoride. It decomposes back to elements at a temperature of above 250 °C. It has a low volatility Applications/Uses It is applied in the treatment of maladies. Radon's molecule-damaging radioactivity has been used to kill cancerous cells. Health mines and spas Radon is used to study atmospheric transport and to explore petroleum and uranium. A. CHLORINE Preparation On a commercial scale chlorine is prepared by electrolysis of an aqueous solution of sodium chloride (brine solution) when Cl2 is evolved at the anode and H2 is evolved at the cathode. Page 27 of 35 Project Work on Gases and their Applications 30th April 2012 Electrolysis 2NaCl + 2H2O ———————> 2NaOH + Cl2 + H2 It can also be prepared by electrolysis of molten NaCl (Down’s cell for the manufacture of metallic sodium). When Cl2 is evolved at the anode and sodium metal at the cathode. Electrolysis 2NaCl + 2H2O ———————> 2Na + Cl2 Properties It combines with metals and non metals to form chlorides. It decomposes water forming HCl and HClO which is unstable and decomposes giving nascent oxygen which is responsible for oxidizing and bleaching action of chlorine. Cl2 + H2O ——> HCl + HClO; HClO —> HCl + [O] Colored matter + O —> Colorless matter. Page 28 of 35 Project Work on Gases and their Applications 30th April 2012 The bleaching action is permanent and color is not restored on standing. However, it cannot be used for bleaching delicate articles such as straw, silk, wool etc. which are damaged by it. Cl2 oxidizes Br– and I– ions to Br2 and I2 respectively. Cl2 + 2X– ——> 2Cl– + X2 (X = Br or I). It combines with alkalies forming hypochlorite and chlorate salts in cold and hot conditions respectively. Cold 2NaOH (dil.) + Cl2 ————> NaCl + NaClO + H2O Hot 2NaOH (conc.) + 3Cl2 ————> 5NaCl + NaClO3 + 3H2O With slaked lime, Cl2 gives bleaching powder (CaOCl2) Ca (OH)2 + Cl2 ———> CaOCl2 + H2O With ammonia, Cl2 reacts as follows: 8NH3 (excess) + 3Cl2 ———> 6 NH4Cl + N2 NH3 + 3Cl2(excess) ———> NCl3 + 3HCl With SO2 and CO, addition compounds are formed SO2 (dry) + Cl2 ——> SO2Cl2 (Sulfuryl chloride) Page 29 of 35 Project Work on Gases and their Applications 30th April 2012 CO + Cl2 ——> COCl2 (Carbonyl chloride or phosgene) Applications/Uses 1. Chlorine is largely used for the sterilization of municipal supply water. 1. It is used as a bleaching agent in paper industry and textile industry 2. It is used in the manufacture of several dyestuff and explosive 3. It is used in the manufacture of synthetic plastics such PVC 4. It is used in the manufacture of refrigerants such as Freon (CCl2F2) B. FLUORINE Preparation: F2 is now prepared by electrolysis of a solution of KHF2 (1 part) in anyhydrous HF (5 parts) in a vessel (modern method) made of Ni — Cu alloy or Ni — Cu — Fe alloy called the Monel metal using carbon electrodes. KHF2 ————> KF + HF; KF ———> K+ + F–; At cathode: K+ + e– ———> K; 2K + 2HF ———> 2 KF + H2 F– ————> F + e–; F + F ———> F2 At anode: Properties It is the most reactive of all the halogens. It combines with metals as well as non-metals to form fluorides. It decomposes water forming O2 and O3 and reacts vigorously with hydrogen of hydrocarbons leaving behind fluorinated hydrocarbons. Cold 2H2O + 2F2 ————> 4HF + O2 Oxidation Page 30 of 35 Project Work on Gases and their Applications 30th April 2012 Hot 3H2O + 3F2 ————> 6HF + O3 Oxidation It reacts with to form nitrogen and with H2S forming SF6. 2NH3 + 3F2 ——> N2 + 6 HF (oxidation reaction) H2S + 4F2 ——> SF6 + 2 HF Fluorine reacts with cold and dilute sodium hydroxide solution to give oxygen difluoride (OF2) 2F2 + 2NaOH (cold, dil) ——> 2NaF + H2O + OF2 However, with hot and concentrated sodium hydroxide solution it gives oxygen 2F2 + 4NaOH (hot, conc.) ——> 4NaF + 2H2O + O2 Since F2 is the strongest oxidizing agent, it is always reduced and hence does not show disproportionation reactions while others halogens do. Uses of fluorine 1. Fluorine is largely used in the manufacture of UF6 for nuclear generation and SF6 for high voltage insulation. 2. It is used in the preparation of DDFT which is more efficient fungicide than DDT 3. It is used to obtain the polymer such as Teflon. The Page 31 of 35 Project Work on Gases and their Applications 30th April 2012 Applications of gases in Bhutan Oxy-hydrogen torch. A mixture of hydrogen and oxygen when burnt in a specially designed apparatus called oxy-hydrogen torch produces temperatures around 25000C which is used for cutting and welding of metals. It has been used in Bhutan in construction of buildings, bridges, etc. In the iron and steel industry, in chemical industries for welding and cutting metals and for blasting of rocks, even for artificial respiration, Oxygen has been used. Production of methanol and carbonated soft drinks , carbon dioxide has been applied as we can find in Pasakha. CO2 in the form dry ice is used in wine making process to cool down bunches of grapes quickly after picking to help prevent spontaneous fermentation by wild yeasts. Where AWP and Bhutan Fruits Products Pvt Ltd in Samtse make used of it. Hydrocarbon gases like propane, ethane and ethylene are useda s domestic fuel in the form of LP gas which Tashi Group of Companies and Damchen petroleum used for its production. Chlorine is largely used for the sterilization of municipal supply water where City Corporation and all the municipal who supply water to the public make used of it. Page 32 of 35 Project Work on Gases and their Applications 30th April 2012 Conclusion Hard works are usually rewarded with success. Success normally correlates with completion of any works. Similarly, with success of completion of this assignment has been quite a rewarding for me. It basically taught us how to develop and enhance our academic skills for prudence. It also really brings to the knowing of doing any assignments- its modes and norms to be abide by. It has been quite a great pleasure me to be a part of this assignment. It taught me so many unknown things. The industrial preparation of every gas has been very interesting to learn and apply in our country if the facilities really can give as a way through. And the properties of each gas too are the significant as it helps us to distinguish amongst the gases present. That will help us to use base on its toxicity. And the applications as general can also very useful for individual who wish to be rich by industrialization. Knowing the applications of all gases it really pep talked me with to start with the industry if the facilities are available. The most important here I could gained is the applications of gases in Bhutan. By knowing their applications we too are boosted with to move ahead and start preparing those gases in large scale for commercial purpose. For example there has been a usage of various gases like carbon dioxide in carbonated soft drinks. And there are usage of so many gases in the iron and steel industry , chemical industries and for welding and cutting metals. There has been so many we are unaware of those. Therefore, this assignment has been quite a helpful, useful, applicable, educational, informative, etc. I shall ensure to apply all the knowledge if the technological facilities give me a way to move ahead. Page 33 of 35 Project Work on Gases and their Applications 30th April 2012 References About ethylene gas. (n.d). Retrieved on March 15th from http://www.ethylenegas.com/ Ethylene. htm Acetylene. (n.d). Retrieved on April 25th from http://en.wikipedia.org/wiki/Acetylene Ethane gas. (n.d). Retrieved on March 15th from http://www.wisegeek.com/what-is-ethane .htm Ethene (ethylene): Properties, Production & Use. (n.d). Retrieved on March 25th from http ://www.ausetute.com.au/ethene.html Occurrence-preparation-of-fluorine (n.d). Retrieved on 12th April 2012 from http://www.transtutors.com/chemistry-homework-help/S-and-P-blockelements/occurrence-preparation-of-fluorine.aspx Industrial preparation of Carbon dioxide (n.d). Retrieved on 17th April 2012 from http://www.lcc.ukf.net/KS3Chem/gasco2.htm Industrial production (n.d). Retrieved on 18th April 2012 from http://www.ucc.ie/academic/chem/dolchem/html/comp/co.html Madan,R.D. & Bisht,B.S.(2007). ISC Chemistry for Class XI. New Delhi: S Chand and company pvt limted. Natural occurrence and Preparation (n.d) Retrieved on 15th April 20120 from http://www.infoplease.com/ce6/sci/A0858584.html#ixzz1sl2iqBCM Krypton (n.d) retrieved on 28th April 2012 from http://www.enotes.com/kryptonreference/krypton-192060 Page 34 of 35 Project Work on Gases and their Applications 30th April 2012 Properties of propane. (n.d). Retrieved on March 30th from http://www.propane101. com/aboutpropane.htm Radon (n.d). Retrieved on 15th April 2012 from http://en.wikipedia.org/wiki/Radon Retrieved on http://www.infoplease.com/ce6/sci/A0858585.html#ixzz1sl6MaPnH Retrieved on 23rd March 2012 from http://answers.yahoo.com/question/index?qid=20071201122849AAKVH31 Srivastava,H.C.(2011). Nootan ISC Chemistry. Uttar Pradesh : Nageen Prakashan private limited. Uses of ammonia. (n.d). Retrieved on April 15th from http://wanttoknowit.com/ uses-of-ammonia/ Page 35 of 35