Is Othello a Victim or Villain?

Is Othello a victim or Villain?This is a play about Othello, a tie upish general in the Venetian army. He is the ultimate villain in this play as opposed to Iago, the high ranking soldier. Most would barrack as a matter of fact that Iago is undoubtedly the villain of this tragic theme. In order to perceive this, a superficial assessment of the ii main characters in the play Othello and Iago, should be unbalancede. The art of analysis on its own rejects the simple easy explanations but rather deals in the difficult and mystifying facts.Although Iago is the natural nuisance and thus the obvious bad guy, his serving is to create the tragedy that this play later gravels. A lengthy circumstance in addition to an open mind will show the verity of the matter. Othello is the actual villain. Even though he initi every(prenominal)y lacks any leering thoughts and ideas, he in timetually digests to become a murderer due to deliriously untrustworthy and jealousy. As you read the pl ay it is non common to accord Othello with such(prenominal) descriptive words as conceited, though he is in every sense of the word.As the plot unfolds it is already clear that Othello is dismissal to fall from grace in a huge way and his untying will be his insatiable ego. He knows his abilities as a gigantic warrior and his superb sword wielding abilities. His prowess on the battle field elevated his ranks to the brim of the military defenses of Venice city. He gained his terrific status due to his expertise as a military officer and with that came his conceit. When Iago tells him of the threats from Brabantio, he feel outs,Let him do his spite My services which I contrive d wholeness the signiory shallout-tongue his complaints (1509).He walks with an argument of everyplace confidence depic pratg tones of arrogance in saying that no one has the authority to accuse is reputation. And to add on to that he shows his lofty opinion, as lofty as it loafer be, by saying,I b ring forth my life and existence from men of royal siege (1509).His head is extrusion with the status and importance instaln to him by the men of power in the city of Venice. He starts to think he is infallible, great and unfaultable, thus enfeebling him to the crucial insights of his enemies as to what they should do to discredit Othello from grace,the Moor already changes with my toxi kittyt d temperousconceits atomic number 18 in their tempers poisons (1555).Whilst Iago reveals his detailed plot, we come to discover round other(prenominal) vice possessed by Othello, he has a jealous mind. This comes as a result of insecurities of his colour, his education and his age.I am black and have not those soft parts of conversation that clamberers have,for I am dec airwaved into the valley of years (1553).Othellos jealousy is fed by the aforementioned insecurities. He says,As he (Cassio) shall smile, Othello shall go mad and his unbookish jealousymust construe poor Cassios smile s, gestures, and light behavior quite in thewrong (1569).Iago therefore unless has to create an opportunity for Othellos jealousy to initiate his downfall.Finally, we take note of his emotional dishonesty. As soon as Iago plants his thoughts, Othellos head and heart quickly fills up with contempt and positionterness. He openly confesses his love for Desdemona but he is easily convinced otherwise by Iago due to his dishonest character importation he was not being truthful about his love for Desdemona. He says,If she be false, O consequently Heavn scoffs itself Ill not believe it (1554),This makes him vowelise like a passionate man yet afterwards gets mad and discredits Emilia as a simple bawd. (1557) since she says the Desdemona is nigh to him. This illustrates his love being no more(prenominal)(prenominal) that a sad illusion, simply an obsession to say the least. His emotional untruthfulness is connected to all his other vices and feeds of them creating a dangerous colo ssus out on a once adorable and admirable man. in snip as much as Othello is the villain of the story, at more than one instance he has appe argond to look like the victim as well. He appears to be a victim of his society and seems as though Iago toys with his irritating nature at his pleasure. Othello seems to be very gullible and at clock very distant from the truth. He is innocent to the working whitethornhems and mischievous plans Iago comes up with.Othello loses his tempers easily as a child does when frustrated and Iago knew how to play with his awry(p) ego that amounted due to the thought that his wife is heating on him. And of ancestry that is blatant lie. All the grace and gentleness that was Desdemona was easily mistaken for flirtations to the unsuspecting Othello. His uncontrollable temper and the proof ca utilize the untimely death of his ever faithful wife. His chemic reaction was like that of a child whose favorite toy had been snatched away. His anger does not e ven give him the time to listen to her side of the story and refuses to listen to her pleas of innocence. Though he has an evil side to him,Othello had turned into an bats state of mind and one could actually state that he magnate not have realized what he was doing until it was a little bit too late.While Othello might have roughly virtuous attributes, there is no doubt that his emotional dishonesty, jealousy and conceit all jibe up to make him the ultimate villain of this Shakespearian classic play. In the remove it is the unwitting prophecy Iago makes that comes true, O, beware, my lord, of jealousy It is the green-eyed monster which doth mock the meat it feeds on that cuckold lives in bliss Who, certain of his fate, loves not his wronger But, O, what damned minutes tells he oer Who dotes, yet doubts, suspects, yet strongly loves(1550). Yes, Iago should be the villain, but we hugely expect this of him, and he therefore lives up to salutary what we would expect.. The true ba d guy, who gives this play its twist is Othello the disingenuous, suspicious and the proud Moor of Venice.Isolation of Elements common Principles and performanceesIsolation of Elements General Principles and ProcessesIntroduction to surfacelurgyOur planet state is a vast source of genes which are distributed in its crust, water bodies and atmosphere. turn up of these elements nearly 80 per cent are ad sorts which travel by either in the combined state or in separated state (called penury state). Metals communicatering in free state are copper, silver, gold and platinum convention admixtures. Not only admixtures some non- alloys withal occur in the free state, such as, atomic number 6, sulphur, nitrogen, oxygen and group 18 elements (the noble gases). Apart from surfaces and non- coats some elements occur as surfacelic elementloids which show both the properties of admixtures and non- coats. Metalloid silicon is the spur of electronic industry and solar cells.Di stribution of elements in the preceding(prenominal) terce categories in shown in the periodic Table (Fig. 6.1, Ref www.wikipedia.org)Fig. 6.1 nigh close to abundant elements in the combined form as solutes areIn earth crust In sea waterO, Si, Al, Fe, Cl-, Na+, SO42-Ca, Na, K and Mg MG2+, Ca2+ and K+Some life supporting metals are press, atomic number 20 and magnesium. Chlorophyll, a compound of magnesium, is responsible for the photosynthesis bear upon in releasing oxygen.General principles of metallurgyFor any application of a metal it has to be produced in a axenic state. Here lies the importance or metallurgy. Metallurgy involves the initial purification and tightness of the ore and its subsequent decrement to metal.Minerals and oresNaturally occurring sources of metals are called minerals which are chiefly pollute with impurities such as days and siliceous matter.A mineral which is exuberant in the metal compound and which cornerstone be apply to natural selection metal economically is termed as an ore. Thus, all ores are minerals but all minerals are not ores. The impurities which are generally present in ores are called gangue.Following is the list of some important ores of a few metalsMetalOreChemical composition exhort (Fe)Photograph of metalsIron pyritesHematite magnetic iron-oretarboosh2Fe2O3Fe3O4Aluminium (Al)Photograph of metalsBauxiteCryoliteAl2O3 . 2H2ONa3 Al F6 copper color (Cu)Photograph of metalsCopper pyritesCupriteMalachite (Green)Cu Fe S2Cu2OCuCO3 . Cu(OH)2Photograph of metals surface (Zn)CalamineZinc zinc blendeZinciteZnCO3ZnSZnOFrom the in a higher place list of ores and also from literature (www.wikipedia.org)You will find that metals generally occur asOxidesSulphides snowatesHalidesSilicatesSteps in the extraction of metals denseness of oresimplification of ore(Chemical simplification or electrochemical substance substance lessening)purgation of metal density of oreOres are usually contaminated with sand and clay mine rals called gangue. in that locationfore, the starting time step to get under ones skin the metal from the ore is to contract as much gangue as possible. To do so the ore is busted to fine particles and subjected to the quest methods of concentrationhydraulic washingcharismatic Separation fizz flotation methodHydraulic washingHydraulic washing is through with(p) with an upwards flow of water. In this figure out visible light gangue particles are washed away leaving behind the desired corpulent are particles.Magnetic separationThis method is based on the diametrical magnetic behavior of gangue particles and the ore. The conclutration of ore is done by putting the dried crushed ore on a conveyor belt moving around a powerful magnetic crimper. In this way the ore is separated from the gangue particles. As an example, magnetite is ferromagnetic and on (Fe3O4).Passing over a magnetic roller it gets carried away and made free from non-magnetic gangue.Froth FlotationThis method is knowing for the concentration of sulphide ores. The method is based on the relative assiduousness of gangue particles and ore particles. Either of two can be made to float on the sedimentary surface with cinch bubbles and be collected. This is achieved by adding some chemical compounds in water. The arrangement is shown is Fig. 6. Air is blown with pressure to create effervesce which engulphes either the gangue or ore particles. Following compoundsFrothers Synthetic detergents, pine, oil, eucalyptus oil or coal tar.Collectors X anthates .These impart water repellent properties to the surface of the ore particles to be floated.Froth Stabilisers Cresols and aniline.Depressants Sodium cyanide.The purpose of a depressant is to make inefficient one component of the mixed ore. For example, from a mixture of ZnS (sphalerite) and phosphate buffer radical (galena) ZnS is NaCNwhile heavier PbS particles float on the surface. withdrawLeaching is extration of an active ingradient of the low build ore. This is done by dissolving the desired component in a desirable chemical solution.Example AreLeaching of low anatomy nose candyate and oxide ores of copper by dilute sulfuric acidCuCO3(S) + H2SO4(aq) CuSO4(aq) + degree centigrade dioxide(g) + H2O(l)CuO(S) + H2SO4(aq) CuSO4(aq) + H2O(l)Leaching of amphoteric arebauxide (Al2O3) with hot sedimentary sodium hydroxide when impurities such as Fe2O3 and silicates pillowAl2O3(S) + 2NaOH(aq) + 3H2O(l) 2NaAl(OH)4 aqNa Al (OH)4 is converted to gross(a) Al2O3 by passing CO2 gas and heating the product Al(OH)3NaAl(OH)4(aq)+CO2(g) Al(OH)3(S) + NaHCO3(aq)Al(OH)3(S) Al2O3(S) + 3H2O(g)Leaching of gold and silver with aqueous sodium cyanide solution in the presence of air4 Au(S) + 8NaCN(aq) + O2(g) + 2H2O(l) 4NaAu(CN)2(aq) + 4NaOH(aq)Ag(S) + 8NaCH(aq) + O2(g) + 2H2O(l) 4NaAgKN)2(aq) + 4NaOH(aq)The respective metals can be obtained by adding zinc which is a more plus metal than either gold or silver2Na Au(CN)2(aq) + Z n(S) Na2 Zn(CN)4(aq) + 2 Au (S)Conversion of ore to oxideMetals use in huge amounts generally occur as sulphides, oxides or snowates. For sulphide and blowate ores it is necessary to convert them into oxide forms prior(prenominal) to their diminution to metals. This conversion is necessary due to the following reason availability of a less costly diminution elementThe thin out back agent should not interact chemically with the metal produced.Availability of a qualified furnace.The production of metal should be cost effective.Fewer impuritiesThere is precisely a cut down agent which meets all the above requirements. Electropositive metals such as magnesium, calcium and aluminium can be used for the chemical reduction of oxide ores. These metals can not be used for the large musical scale production of less electropositive metals because of their high cost. However, carbon as century fits well as a simplification agent within the above listed parameters. Its oxide, carb on monoxide is also a very good reducing agent. The competency of carbon monoxide as a reducing agent increases with the increase in temperature. One serious drawback of coke is that it reacts with many transition metals and some non-transition metals at higher temperatures to form carbides. However, carbon as coke and carbon monoxide remain the two versatile reducing agents for iron ores.For carbon to be used as a reducing agent the sulphide or carbonate ores have to be converted into their respective oxide forms. century does not slim sulphide ores to give metals. To find out the reason consider the following two reduction reactions2MS (S) + C(S) 2M (l or S) + CS2(g) .(i)(sulphide form)MO (S) + C (S) M (l or S) + CO (g) (ii)(Oxide form)For these two reduction reactions by carbon the Gibbs energy of the reaction should be negative. This can happen only when G for CS2 will be more negative than G for MS (first reaction) and for the second reaction G for CO should be more negative than G for MO. Thermodynamically the first reaction where CS2 is formed is not feasible, but the record reaction is feasible. It may be noted that CS2 is very much less stable than CO gas. Therefore, the sulphide ores are first converted into the oxide form sooner reducing them with coke.This is done by heating the sulphide ores in the presence of roast the sulphide ors is that a by-product sulphur dioxide (SO2) is obtained which is used to manufacture sulphuric acid.To get the ores into their respective oxide forms following military operationes are usedCalcinationCalcination is heating the ores in the absence seizure of air. This method is used for the carbonate, hydroxide and hydrated oresCaCO3(S) CaO(S) + CO2(g)(calcite)MgCO3. CaCO3(S) MgO(S) + CaO(S) + 2CO2(g)(Dolomite)CuCO3. Cu(OH)2(S) 2CuO(S) + CO2(g) + H2O(g)(Malachite)Calcination is generally done is a reverberatory furnace (Fig. 6. Ref www.wikipedia.org). This appendage makes the ore process and easily workable. cookRo asting is heating the ores in the presence of air. This is done mainly for sulphide ores2 Fe S2 (S) + 5O2(g) 2FeO(S) + 2SO2(g)(iron pyrite)2Cu2S(S) + 3O2(g) 2Cu2O(S) + 2SO2(g)(copper glance)2ZuS(S) + 3O2(g) 2PbO(S) + 2SO2(g)(Galena)Roasting is done in reverberatory furnace (Fig. 6.4 Fef. www.wikipedia.org)Roasting also removes inconstant impurities like sulphur, arsenic and phosphorus as their volatile oxidesS(S) + O2 (g) SO2(g)4AS(S) + 3O2(g) 2AS2O3(g)P4(S) + 5O2(g) P4O10(g)Student employment 1Metals used in an ordinary filament bulb hound the figure or an ordinary bulbLabel various metals used in itGive reason as to why tungsten metal is used as the filamentStudent Work winding-clothessStudent Worksheet 1Which metal is liquid at room temperatureAluminiumLeadMercuryZincLeaching is generally used for the following ores of metalsLeadCopperIronAluminiumIn Aluminium-thermite process the reducing agent used isCarbonHydrogenAluminiumSodiumHeating of ores in the absence of air i s known asRoastingCalcinationLeachingBensemerizationFroth flotation process is used to concentrate the following oreHalideSilicatesSulphidecarbonatehow do metals occur in nature by virtue of their reactivitygiving chemical equations describe the process of calcinations and roasting, respectively.Why are sulphide ores roasted to their oxide forms before their reduction with coke? hunt the principle of leaching with suitable examples.Describe the principle of froth flotation process. How is PbS ore concentration ewhen it is contaminated with ZnS? stockyS. No.DescriptionOreA mineral with high concentration of metal compound which is used to extract metal profitably.Occurrence of metals in natureOxidesSulphidesCarbonatesSilicatesGangueUndesired real(a)s present in ore.MetallurgyProcess of isolation of metals from ores involving the stepsConcentration of ore decrease of ore to metalPurification of metalConcentration of oreMagneticFroth floatation (for sulphide ores)LeachingLeachingExtra ction with a suitable solvent for low grade ores.CalcinationsHeating of ores (carbonate or hydroxide) in the absence of air.RoastingHeating of ores (sulphide ores) in the presence of air.SmeltingIndustrial reduction process to obtain metal from ore.Reducing agents used in smeltingHydrogenCarbon as cokeAluminium (In Alumino-thermite processAirElectrolyticRefining of vernacular metalLiquationCupellationBesemerization (known as oxidative refining)Vapour phase (van Arkel and de Boer, and Mond processes). regularize refining (for silicon)HydrometallurgyElectrolyticEllingham diagramsCurves of Gibbs energy vs temperature. Used to select a suitable reducing agent.LOW CHART1.2.Classification of ores on the basis of the metal compoundsConcentration of ores on the basis of their chemical nature3.4. reduction of ore to get the metal choosing a suitable reducing agentPurification of crude metal based on the nature of impurities presentCrosswordA mineral having high concentration of a metal com pound. OREHeating or ore in the absence of air. CALCINATIONSHeating of ore in the presence of air. ROASTING worth(predicate) by-product during roasting. SO2 gasExtraction of low grade ores. LEACHINGConcentration of ore by proving air bubbles. FROTH FLOTATIONA furnace used for the smelting of iron ore. BLAST FURNACEProcess of reduction of metal oxides by aluminium. ALUMINO-THERMITE PROCESSProcess used to obtain very high pure silicon. ZONE shadeCarbon monoxide is used to purify nickel. MONDS PROCESSZirconium tetraiodide (Zrl4) vapours are decomposed on het up up tungsten filament. ARKEL-DE BOER PROCSSSodium is obtained by passing electric current in molten sodium chloride. ELECTROLYTIC REDUCTION extra RESOURCE LINKSwww.wikipedia.orgReduction of ore to crude metalBy development the process of reduction, roasted or calcined ores are converted to crude metal. diametrical reducing agents are used depending upon the reaction between the metal oxide and the reducing agent.Reduction wi th carbon FeZO3, CuO, ZuO, SuO2, PbO and so forthReduction with Aluminium FeZO3, Cr2O3, Mn3O4, TiO2 etc.Reduction with Magnesium B2O3, TiCl4, etcReduction with hydrogen WO3, MOO3, GeO2, CO3O4 etcReduction with CO Fe2O4, FeZO3, PbO, CuOElectrolytic reduction Electrolyzing of oxides, hydroxides orchlorides in fused state.Smelting This is a process in which oxide of a metal is mixed with coke and a suitable flux. The mixture is heated to a high temperature in a blast furnace. Iron, Copper, Zinc and tin can be obtained by this process. Carbon is a good reducing agent below 983K where as above this temperature CO acts as reducing agent.ZnO(S) + C(S) Zn(S) + CO(g)Zincite+ 2C(S) Sn(S) + 2CO(g)Cassitesite PonderedanthraciteFe2 + 3C(S) 2Fe(S) + 3CO(g)HaemetiteCuO(S) + C(S) Cu(S) + CO(g)A flux is a substance which is added to roated or calcined ore during smelting to remove the non-fusible impurities of argentiferous oxides, silica, and silicates etc. During smelting flux combines wit h the non-fusible impurity to convert it into fusible material called slag. The slag being light float over the molten metal from where it is removed.Flux is of two types bitteric flux SiO2 Basic flux calx stone (CaCO3) and Magnetite (MgCO3)SiO2 + MgCO3 MgSio3 +SiO2 + CaCO3 CaSiO3 +Hydrometallurgy Copper, silver grey and gold are extracted by this process. The process is based on the principle that more electropositive metal can displace less electro positive metal from its salt solution. The one is set with such seagents that the metal forms a soluble compound. On adding more electropositive metal to the solution, the less electropositive metal present in the solution is precipitated.Example Extraction of Copper Malachite ore is roasted and oxide formed is dissolved in sulphuric acid. On adding scrap iron to the solution, copper is precipitated.Cu(OH)2 . CuC 2CuO(S) + H2O(P) + CCuO(S) + H2S CuS +CuS + Fe(S) Cu(S) + FeSExtraction of silver ore is dissolved in NaCN solutio n and air is blown followed by addition of Zinc turnings. Silver is precipitated.Ag2S + 4NaCN 2NaAg(CN)2 + Na2S2Na Ag(CN)2 + Zn Na2 Zn(CN)4 + 2AgSolutionAcid flux used to remove basic impuritiesBasic flux used to remove acidic impuritiesReduction with hydrogen Some of he metal oxides (mostly transition metals) can react with carbon at high temperatures to give metal carbides which resist further oxidation. Oxides of these metal, are better trim by hydrogen gas. i.e.WO3 + 3H2 W + 3H2O(g)MOO3 + 3H2 Mo + 3H2O(g)GeO2 + 2H2 Ge + 2H2O(g)CO3O4 + 4H2 3Co + 2H2O(g)Using H2(G), metals are obtained in small scale as hydrogen is highly explosive.Aluminium reduction method This method is also called Alumino-thermite process. Some of the metal oxides cannot be reduced by carbon as affinity of oxygen for the metal is more than for carbon, also, metal may form carbide at high temperature. Such metallic oxides are reduced by using aluminium powder. The reaction is initiated by the using barium per oxide and a small piece of Mg ribbon.Fig.Cr2 + 2Al(S) 2Cr(P) + Al2Fe2 + 2Al(S) 2Fe(P) + Al23Mn3 + 8Al(s) 9Mn(P) +4Al2 mould of BaO2 is to provide oxygen to magnesium when lot of heat is volved which initiates the thermite process.Air reduction Sulphide ores of less electro positive metals such as Hg, Pb and Cu etc are heated in air to partially convert the ore into oxide which then reacts with the remaining sulphide in absence of air to give the metal and SO2 gas.2HgS(S) +3 2HgO + 2S2HgO(S) +HgS(S) 3Hg + SReaction on p-5This process may also be called ante reduction process.2PbS + 3O2 2PbO + 2S2Pbu + PbS 3Pb + S2Cu2S + 3O2 2Cu20 + 2S2Cu20 + Cu2S 6Cu + SReduction by Electrolysis The oxides of highly electropositive metals of group I, II and Al element of group etc cannot temperatures and these can form carbides. These metals are obtained by electrolysis of their oxides, hydroxides or chlorides in fused state. To lower the fusion temperatures or to increase the conductivity or bo th a small amount of other salt is added. The metal is liberate at cathode.Sodium metal is obtained by electrolysis of fused mixture of Nacl and Cacl2 (downs process) or by electrolysis of fused sodium hydroxide (Costners process).Nacl Na+ + cl- fusedAt anode cl- Cl + e-Cl + cl cAt Cathode Na+ + e- Na(l)Aluminium metal is obtained by electrolysis of fused mixture of alumina and Gyolite (Na3Al F6)Na3 Al 3Na F(P) + AlAl Al3+ + 3F-At anode F- F + e-F+F F2(a)2A+ 6 4Al + 3O2(g)At cathode Al3+ + 3e- A(l)Anode gets cosseted by oxygen liberated during electrolysis, which needs replacement from time to time.Refining of metals Metals obtained by any of the reduction method except electrolytic capacitor reduction contains impurities. Refining of metals is process where by undesired impurities present in the metals are removed. Different refining processes may be applied depending upon the nature of the metal and nature of impurities.Name of the ProcessMetal to be polishedLiquationL ow melting metals like Sn, Pb, Bi and Hq etc.CupellationSilver containing lead.( adulterated silver containing lead is heated in cupel made of thrum ash or cement and a blast of air is passed over the molten mass. The impurities are oxidized and removed with the blast of air)BessemerisationFe and CuVapour phase refiningThere are two methodsMonds processImpure Ni is heated with CO(g)at 323K when volatile Ni (CO)4is formed. These vapours of Ni(VO)4are passed into another chamber maintained at 306K when Ni (CO)4decomposes to pure Ni which gets deposited on small Ni balls kept in the chamber and carbon-monoxide gas is rejected.Ni(S)+4CO(g)Ni(CO)4Ni(S)+ 4CO(g) vanguard Arkel ProcessTi, Zr, Hf, V, Th, B are clean by this method. Impure metal is heated with I2, producing volatile T1I4,, ZrI4or BI3. These vapours are passed over electrically heated filament of Tungsten. The vapours decompose, metal gets deposited over the filament and iodine liberated is .Ti(S)+ 2TiTi(s) + 2Zr(S)+ 2ZnZr(s ) + 22B(S)+ 32B 2B(s) + 3Zone refiningHighly pure silicon or gernanium required for making semi-conductors are refined by this method. The impure rod of silicon or germanium is surrounded by a heating cir-l which can move from one end to another. The skunk is allowed to move in one particular direction. As the heater moves away, the metal capitalizes and impurities move along the direction of the movement of the heater. The process is repeated a number of times when a small portion of the rod gets purified. The end portion of the rod having high concentration of impurities can be cut and disconded.Electrolytic refiningMost of the metals like copper, silver, gold, aluminium, lead etc are refined by this process. The impure metal is made the anode and a thin sheet of pure metal is made a cathode. The electrolytic solution consists generally of an aqueous solution of a salt containing some acid or a complex of the metal.Purification of CopperAnode Impure copperCathode small sheets of pure copperElectrolyte An aqueous solution of copper sulphate containing some H2SO4.Purification of SilverAnode Impure silverCathode Thin sheet of pure AgElectrolyte An aqueous solution of ASNO3containing HNO3.PbAnode Impure metalCathode canvas of pure leadElectrolyte A solution of PbS1F6containing 8-10 of H2S1F6.Purification of SnAnode Impure TinCathode A sheet of pure tin metalElectrolyte An aqueous solution of SNSO4containing H2S1F6.Thermodynamics of Metallurgical process The metals are extracted when their oxides are heated with carbon or other metal and by thermal decomposition. For any extemporaneous reaction, the Gibbs anergy change G must be negative at a particular temperature.G = H TSH is enthal by change during the reaction, T is the absolute temperature and change during the reaction, T is the absolute temperature and S is the south change during the reaction. The reaction will processed only when G is negative. For reaction where H is negative and S is positi ve. The reaction proceeds even at low temperatures.Theoretically, it is possible to decompose all metal oxides if sufficiently high temperature is attainable but oxides of Ag, An and Hg are the only oxides which can be decomposed at easily attainable temperatures. Hence these metals are obtained by thermal decomposition of their oxides.The choice of reducing agent to obtain the metal from its oxide depends upon the change in Gibbs energy G. The plot of Gibbs energy change versus temperature is called.Ellingham disgram There diagrams can be drawn for different compounds such as oxides, sulphides, halides etc. using these diagrams one can make a choice of reducing agent and the corresponding temperature at which, the reaction becomes feasible. G for the reaction is -ve.Some salient features of Ellingham diagram areThe slope for metal to metal oxide is upward as Gibbs energy change decreases with increase of temperature.The all follow a straight line unless they melt or vaporize. When change in entropy is large, the slope of line also changes for example the Hg-HgO line changes slope at 629K when mercury brills and similarly Mg-MgO changes slope at 1393K.When temperature is increased, the graph crossed the line G=0 at a particular temperature. Below this temperature, G being negative, oxide is stable where as above this temperature G is positive and the oxide become unstable. Thus it should decompose into metal and oxygen.In a number of reduction processes, one metal is used to reduce the oxide of the other metal. Any metal can reduce the oxide or the another metal which lie above it in Ellingham diagram.Ellingham diagrams give an indication whether the reaction is possible or not. These graphs do not predict the kinetics of the reaction. This is a major limitation of Ellingham diagrams.Ellingham diagram of carbon Carbon reacts with oxygen to give two oxidesC(S) + O2(g) CO2(g)2C(S) + O2(g) 2CO(g)Carbon monoxide can further react with oxygen to give carbon dioxi de.2CO(g) + O2(g) 2CO2(g)When carbon changes to carbon dioxide, change in entropy (S) is very small and G hardly shows changes with increasing temperature. The graph of G against T is almost horizontal.When carbon changes to carbon monoxide, S is positive and G becomes more negative with increasing temperature. As a result, the line shows downward slope. The two lines for carbon to carbon-dioxide and carbon to carbon monoxide cross at 983K. below this temperature arrangement of CO2 is favoured whereas above this temperatures formation of CO is preferred.Ellingham diagram of metal sulphide Some metals occur in nature as sulphides, such as ZnS, CuS and PbS. The reaction for the reduction of these sulphides with carbon is highly2MS(S) + C(S) 2M(S) + CS2(g)unfavourable energetically because of the instability of carbon disulphide. It being an endoergic reaction, sulphide ores are roasted to oxides and their reduced into metals.