 fifth point you see reaction of carbon with O2 reaction of carbon and O2 two reactions possible we know already like C plus O2 gives CO2 this is first reaction and C plus half O2 gives CO this is second reaction in this reaction you see in the first reaction the volume of CO2 obtained volume of CO2 obtained it is same as the volume of O2 used volume of O2 used okay one volume in one volume hence what happens hence delta S delta S is very small almost zero and delta G hardly changes with temperature right one volume of this gas gives one volume of CO2 gas so number of gases particles same both side so entropy won't change that much delta S is almost zero hence delta G won't change with temperature that's why you see the line of C and carbon well a line is all almost parallel to the x axis like this we have in the Ellingham diagram I'll show you just let me write down this first same logic if you apply here right in the second reaction we can say the volume ratio I'll write down like this the volume of O2 divided by the volume of CO is half right to get one volume of CO we'll use half volume of O2 or we can say to get two volume of CO we'll get one volume of O2 right so half of the volume of O2 required to get one volume of CO right hence if you calculate delta NG here so delta S will be positive greater than zero and we can say delta G becomes more negative delta G becomes more negative as temperature increases as temperature increases and that is why the line goes like this this kind of line we have in the graph so what we can say here to conclude this below 710 degrees Celsius reaction gives CO2 above 710 degrees Celsius the reaction gives CO this is what the overall thing is okay now when you see this Ellingham diagram you see here at 710 there is almost no change in delta G till 710 right and as I discussed that when the temperature increases this line gives you what this line gives you C plus half O2 gives CO so delta G for this reaction just now I have discussed delta G becomes more negative and hence the line has to go down that's why it goes like this so after the 710 this line represents the formation of carbon monoxide and below this 710 the line represents the formation of carbon dioxide okay so these are the key features of Ellingham diagram aluminium with carbon right aluminium with carbon you see this diagram Ellingham diagram what we have you see here aluminium and carbon aluminium is here where is aluminium here and carbon is this right see this thing first of all you understand one thing the logic is the one which is down will oxidize the one which is up right or in other word what we can say the one which is up can reduce the one which is down right this diagram is a rough diagram Krishna I'm telling you this diagram is a rough diagram so maybe some temperatures maybe here and there that precise thing we cannot draw right but actual diagram if you see in the book with respect to that you can say like here you see suppose if this diagram is exactly correct we are assuming right if this we are assuming it it has exactly correct so what you do you just um compare this point at this temperature suppose this is exactly correct diagram we have so at this temperature whatever the temperature it is suppose we have 13 degree Celsius somewhere here we have so what we can say this line represents carbon and CO O2 gives CO right so we can say below this temperature around 13 degree Celsius right carbon can reduce chromium right and chromium will oxidize carbon so it forms CO and chromium will get reduced but above this temperature what we can say chromium reduce carbon but carbon and carbon oxidizes chromium that's what we can say if this diagram is exactly correct again I'm telling you this is the rough diagram here maybe some temperature here and there we'll have you over here so exact thing is what what you need to keep in mind at a given temperature if metal A is above then metal B then we can say A can reduce B right at a given temperature so exact diagram you can go through in the book and see how it is given and from that you can say anyways whatever metal is the concept is this only understood did you copy down this can you move on okay now in this chapter we are left only with the extraction of some metals okay so that we are going to start Ellingham we have done we have also done the what is the various processes by which we can extract a metal now for specific metal what is the process we use so first you write down extraction of copper extraction of copper the ore that we use to extract copper is copper pyrite copper pyrite and we use in this the process that we use is smelting all these things you need to memorize you can read this in ncrt whatever ncrt given in ncrt that is more than enough okay the process is the same that we have discussed okay but here also we'll see I'll just draw the flow sheet here okay so what we do first of all we'll take copper pyrite copper pyrite what we do this copper pyrite we'll take must be crushed and sieved right crushed and sieved we crushed it and we'll sieve it right we'll take the all the major impurities the larger size impurities out from this okay in this ore now we'll do the concentration of this that's what we did okay we've discussed the general process that we discussed that is what we are following here then we'll do the concentration concentration of this ore and concentration will do here by froth floatation process what is froth floatation process again we have discussed okay so what we do here we'll write we'll take the ore that is powdered ore and we add h2o into this we'll add pine oil what is the use of this I'll tell you pine oil and air will allow to pass through this basic thing we have already discussed we'll get sulphide ore in the froth why we use pine oil pine oil that we use here pine oil we add and we also add potassium xanthate potassium xanthate you know this potassium xanthate act as a collector that we have discussed pine oil and potassium xanthate act as a collector and then what we do we'll do the agitation with this what happens impurities settles down into the bottom in the froth you have sulphide or we'll take this out okay second process is concentration by flow floatation process and we add pine oil and potassium xanthate into it okay as a collective that's what the thing is now the next step is what after concentration we'll get concentrated ore then we do the roasting of it roasting and roasting takes place in presence of air that we already discussed right in this process what happens the concentrated ore here that we get in this process the concentrated ore is heated strongly at very high temperature that should be less than the fusion temperature heated strongly right and the impurity that is present here suppose we have sulphur combines with O2 forms SO2 we'll remove this sulphur dioxide arsenic is one of the impurity combines with again O2 it gives arsenic oxide right Sb attached with O2 and forms again the oxide of it these two oxides are volatile in nature and hence escape right overall if you see the reaction in this the copper pyride which is 2 Cu FeS2 with oxygen it converts into Cu2S plus FeS plus O2 which further converts into the oxides of iron and the oxides of copper Cu2 this is what we get in this process okay this is the process roasting we have all these reactions takes place okay finish this one you'll hear okay now the third step is third step is smelting smelting that we do in blast furnace in presence of air blast furnace in presence of air the reactions we have here is this FeS plus Cu2 whatever iron oxide iron sulphides are left that will also oxidize into its oxides plus Cu2S FeO further combines with SiO2 and forms FeSiO3 right so most of the iron here removed in the form of this slag most of Fe removed in the form of slag okay in this process what happens the roasted ore that we get in the last step is mixed with in smelting the roasted ore mixed with coke and silica coke and silica right we add silica over here after this the next process we have here is Bessemerization and this takes place in Bessemer converter again in presence of air here also in this step also we add silica here also we add silica why we add silica that also we'll understand here but we see this first the reaction over here whatever iron sulphide is left here in the previous step it gets oxidized into its oxidized into its oxides FeO plus SO2 sulphur dioxide FeO again combines with this silica SiO2 and forms slag which is FeSiO3 copper sulphide 2 Cu2S also combines with oxygen and forms oxides of copper with sulphur dioxide in this Cu2 and Cu2S there is auto reduction okay they get reduced right auto reduction Cu2O and Cu2S combines goes under also auto reduction and forms copper plus SO2 okay two molecules of this we take it will be 6 and SO2 this copper we call it as blister copper blister copper which is 98% pure 98% pure blister copper okay and further in the last step we'll do the refining of it and for that we use electrolytic refining the last step is electrolytic refining so in electrolytic refining what is the anode we use anode is impure right so we use impure copper plate impure Cu plate large one cathode is what pure Cu plate because we have to take the same metal right electrolyte what we use we can use ions solution of copper CuS4 with S2S4 also we can use by S2S4 we are using because we won't want this sulphur to get reduced right that's why we are using S2S4 in this what happens the pure copper deposited at cathode pure copper deposited at cathode this is the overall process we have