Chemistry - Metallurgy Question with Solution | TestHub
Refining of crude metal is carried out by physical methods, chemical methods and finally electrolytic refining. chemical methods of refining like oxidation, poling are best explained by Ellingham diagram. Consider following Ellingham diagram and answer following given questions :
Which of the following species thermodynamically can NOT reduce FeO at temperature range to 1500°C on the basis of above diagram ?
Options:(select one or more)
Answer:
Solution:
In an Ellingham diagram, a reducing agent can only reduce a metal oxide if its free energy () formation line lies below the metal oxide's line at that temperature.
Si and Mn: Their lines (SiO₂ and MnO) lie below the FeO line between and , meaning they can reduce FeO.
CO and Cu: Their lines (CO₂ and Cu₂O) lie entirely above the FeO line in this temperature range.
Conclusion: Therefore, CO and Cu thermodynamically cannot reduce FeO.
Correct Options: (C) CO and (D) Cu
