InterviewSolution
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InterviewSolution
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The selection of reducing agent depends on the thermodynamic factor.Explain with an example. |
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Answer» Solution :From the Ellingham diagram ,it is clear that METALS for which the STANDARD free energy of formation`(Delta_(f)G^(@))` of their oxides is more negative can reduce the metal for which the standard free energy of formation `(Delta_(f)G^(@))` of oxides is less negative.Thermodynamic factor has a major role in selecting the reducing agent for a PARTICULAR reaction.Only that reagent will be preferred which will lead to decrease in the energy `(DeltaG^(@))` at a certain SPECIFIC temprature. E.g. Carbon reduce ZnO to Zn but not CO. `ZnO+CtoZn+CO` `ZnO+COtoZn+CO_(2)` In the first case,there is increase in the magnitude of `DeltaS^(@)`while in the second case,it almost remains the same.In other words,`DeltaG^(@)` will have more negative value in the first case,when C is the reducing agent then in the second case when CO acts as the reducing agent.Therfore ,C is a better reducing agent. |
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