Question

At what temperature, reduction of lead oxide to lead by carbon i.e., `PbO(s) +C(s) rarr Pb(s) + CO(s)` becomes spontaneous. For the reaction , `Delta H ` and `Delta S` are 108.4 kJ `mol^(-1)` and `190.0 JK^(-1) mol^(-1)` respectively.

Answer 1

Correct Answer - Above `570.5K`
At equilibrium, `T = (DeltaH)/(DeltaS) = (108400 J mol^(-1))/( 190 JK^(-1) mol^(_1)) = 570 . 5K`
Above 570.5 K, `Delta G` will be `-ve` and the reaction will be spontaneous.