Quick Recap — Combined Thermodynamic Calculations (Hard)

  • ΔG=ΔH−TΔS\Delta G=\Delta H-T\Delta S; crossover temperature T=ΔH/ΔST=\Delta H/\Delta S.
  • ΔG∘=−2.303RTlog⁡K=−nFE∘\Delta G^\circ=-2.303RT\log K=-nFE^\circ; ΔSsurr=−ΔHsysT\Delta S_{surr}=-\dfrac{\Delta H_{sys}}{T}.
  • Bond-enthalpy and Hess cycles combine additively; isothermal reversible work w=−2.303nRTlog⁡V2V1w=-2.303nRT\log\dfrac{V_2}{V_1}, and ΔS=2.303nRlog⁡V2V1\Delta S=2.303nR\log\dfrac{V_2}{V_1}.
  • Maximum useful (non-PV) work obtainable =−ΔG=-\Delta G.