Topic: Thermodynamics
Your central place for worksheets, question banks, videos, and more.
Practice Test
Deep Thinking Challenges
Reading Beyond A-Level
A key principle at A-level is that a reaction is only feasible if the Gibbs free energy change (ΔG) is negative. Ellingham diagrams apply this principle graphically to metallurgy by plotting ΔG against temperature (T) for the formation of metal oxides.
Analyse the thermodynamic basis for the structure of an Ellingham diagram, explaining why the lines for most metal oxide formations have a positive gradient. Then, by comparing the lines for the oxidation of iron and the oxidation of carbon, explain how the diagram can be used to predict the minimum temperature at which carbon monoxide can be used to successfully reduce iron(III) oxide (Fe₂O₃) in a blast furnace.