using Ellingham diagram indicate the lowest temprature at which ZnO can be reducedto zinc metal by carbon.Write the overall reduction reaction at this temprature.

using Ellingham diagram indicate the lowest temprature at which ZnO ca

1.	using Ellingham diagram indicate the lowest temprature at which ZnO can be reducedto zinc metal by carbon.Write the overall reduction reaction at this temprature.
Answer» Solution :Ellingham diagram shows variation in standard Gibbs free energy change with temperature for the formation of oxide.The Ellingham diagram shows straight line upward slope with formation of oxide,but in case of ZNO there is sudden change,Ellingham diagram helps in the selecting suitable reducing AGENT. By seeing the Ellingham diagram ,the free energy formation `(Delta_(f)G^(@))` of CO from C becomes lower temprature above 1120 K while that of `CO_(2)` From C becomes lower above 1323 K than `Delta_(f)G^(@)` of ZnO. As `Delta_(f)G^(@)` of `CO_(2)` from CO is always higher than that of ZnO.So C can reduce is better reducing than CO for ZnO. `underset(("Magnesite"))(MgCO_(3))overset(800^(@)" to "1000^(@))tounderset(("Magnesia"))(MgO)+CO_(2)uarr`