Q6. ΔG, ΔH and ΔS of an all-solid cell reaction from emf
For the following cell Pb | PbCl₂(s) | PbCl₂(soln) | AgCl(s) | Ag, the potential at 298 K is 0.490 V and the variation of emf with temperature is given by E = a − (1.86 × 10⁻⁴ V/K)(T − 25 K). Calculate ΔG, ΔH and ΔS for the reaction at 298 K.
Answer in brief
Cell reaction Pb(s) + 2AgCl(s) → PbCl₂(s) + 2Ag(s), n = 2; ΔG = −94.56 kJ mol⁻¹, ΔS = −35.89 J K⁻¹ mol⁻¹, ΔH = −105.25 kJ mol⁻¹.
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Coverstemperature coefficient of emfGibbs–Helmholtz equationthermodynamics of galvanic cellsΔG = −nFEentropy from emf