Get Detailed Explanation on Ellingham Diagram For CBSE Board Class 12 Chemistry. Ellingham Diagram is a lesson under General Principles and Process of. Ellingham Diagram. An Ellingham diagram shows the relation between temperature and the stability of a compound. It is basically a graphical representation of Gibbs Energy Flow. Here ΔG is plotted in relation to the temperature. An Ellingham diagram is a graph showing the temperature dependence of the stability for compounds. This analysis is usually used to evaluate the ease of reduction of metal oxides and sulfides.‎Thermodynamics · ‎Diagram features · ‎Reducing agents · ‎Use of Ellingham diagrams.


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The diagram is ellingham diagram explanation plot of Gibbs free energy versus temperature. This form of energy reaction measures the required thermodynamic driving force to trigger a reaction.

Ellingham diagram - Wikipedia

A positive value means a reaction will not occur, while a negative value indicates otherwise. This tool is very useful in various industries for monitoring and preventing corrosion. Corrosionpedia explains Ellingham Diagram In an Ellingham diagram, the Gibbs free energy of a reaction is plotted against temperature, which can be illustrated in a chain of straight lines where there is a Y-intercept and a slope.

Ellingham diagram explanation slope changes as ellingham diagram explanation subjected material vaporizes or melts.

For oxidation of carbon, the red line is for the formation of CO: As with any chemical reaction prediction based on purely thermodynamic grounds, a spontaneous reaction may be very slow if one or more stages in the reaction pathway have very high activation energies EA. If two metals are present, two ellingham diagram explanation have to be considered.

Diagram features[ edit ] Curves in ellingham diagram explanation Ellingham diagrams for the formation of metallic oxides are basically straight lines with a positive slope.

What is an Ellingham Diagram? - Definition from Corrosionpedia

Ellingham diagram explanation lower the position of a metal's line in the Ellingham diagram, the greater is the stability of its oxide. For example, the line for Al oxidation of aluminium is found to be below that for Fe formation of Fe 2O Stability of metallic oxides decreases with increase in temperature.

Highly unstable oxides like Ag 2O and HgO easily undergo thermal ellingham diagram explanation.


If the curves for two metals at a given temperature are compared, the metal with the lower Gibbs free energy of oxidation on the diagram will reduce the oxide with the higher Gibbs free energy of formation. For example, metallic aluminium can reduce iron oxide ellingham diagram explanation metallic iron, ellingham diagram explanation aluminium itself being oxidized to aluminium oxide.

This reaction is employed in thermite.

The greater the gap between any two lines, the greater the effectiveness of the reducing agent corresponding to the lower line.

The intersection of two lines implies an oxidation-reduction equilibrium.

At the point of intersection the free energy change for the reaction is zero, below this temperature it is positive and the metallic oxide is stable in the presence of the ellingham diagram explanation, while above the point of intersection the Gibbs energy is negative and the oxide can be reduced.

Reducing agents[ edit ] In industrial processes, the reduction of metal oxides is often effected by a carbothermic reactionusing carbon as a reducing agent.

Carbon is available ellingham diagram explanation as coalwhich can be rendered to coke.