Question

An Ellingham diagram provides information about ______.

Options

• the kinetics of the reduction process.

• the conditions of pH and potential under which a species is thermodynamically stable.

• the pressure dependence of the standard electrode potentials of reduction reactions involved in the extraction of metals.

• the temperature dependence of the standard Gibbs energies of formation of some metal oxides.

Answer 1

An Ellingham diagram provides information about the temperature dependence of the standard Gibbs energies of formation of some metal oxides.

Explanation:

The Ellingham diagram is the graph of ΔG° vs. T of any metal/element oxide. Since

ΔG° = ΔH° − TΔS°

For most metal oxide formations:

\[\ce{metal_{(s)} + oxygen_{(g)} -> metal oxide_{(s)}}\]

ΔH° = −ve; ΔS° = −ve

So, the graph will be a straight line with a negative intercept and a positive slope.