Question

With respect to an ore, Ellingham diagram helps to predict the feasibility of its:
A) Vapour phase refining
B) Zone refining
C) Electrolysis
D) Thermal reduction

Answer 1

Hint: The Ellingham diagram deals with the prediction of the process that involves heat and reduction of the metal oxides and sulphides. Thus, this fact leads you to the required answer.

Complete step by step solution:
We have studied diagrams which deal with temperature dependence, heat dependence and several other parameter dependence reaction graphs like isothermal curve, isobaric curve and so on.
Let us now understand the base of the Ellingham diagram and that helps us to deduce the correct answer.
- Basically an Ellingham diagram is defined as the graph which shows the temperature dependence of the stability of compounds.
- The analysis of this graph is used for the prediction of equilibrium temperature between metal, its oxide and oxygen, also the reactions of a metal with the sulphides.
- The main application of Ellingham diagram is its use in metallurgy. It helps to select the best reducing agents for several ores in the process of extraction and purification.
- Feasibility is nothing but the reaction to happen spontaneously that is no extra energy is needed to be put in for the reaction to occur.
- Therefore, Ellingham diagrams are the graphical form of principle that thermodynamic feasibility of the ores involved in reaction that depends on the sign of Gibbs free energy.

Therefore, the correct answer is option D) Thermal reduction.

Note: The Ellingham diagram is the analysis which is actually thermodynamic in nature that is thermodynamic feasibility of a reaction that depends on Gibbs free energy change and ignores the reactions which are kinetically favoured