Question

From the richardson ellingham chart, will:

a) aluminum reduce Fe2O3 to iron at 1200 C?

b) An atmosphere with a CO/CO2 ratio of 0.06 oxidze nickel at 800 C?

c) Silica Oxidize liquid zinc at 700 C?

d) Sodium reduce water to oxygen and hydrogen at 500 C?

Answer 1

richardson ellingham chart is used to find the free energies of the oxidation and reduction. The chart gives free energies of oxidation. Reduction free energy will be negative of the value given in chart.

a) Gibbs energy from the chart = 800 (for oxidation of aluminium) - 75(for reduction of iron) = positive

b) -425 + 300 = negative

c) -(very small, not shown in chart) +500 = Positive

Gibbs energy has to be negative for thermodynamic feasibility of the reaction. Similar to the above parts,