The cell potential (Ecell) of a reaction is related as ΔG=nF Ecell, where ΔG represents maximum useful electrical work.
n = no. of moles of electrons exchanged during the reaction.
For reversible cell reaction d(ΔG)=(ΔV)dp−(ΔS)dT
At const. P, d(ΔG)=−(ΔS)dT
At const. P, ΔG=ΔH−TΔS. (1)
∴ ΔG=ΔH+T(d(ΔG)ΔT)P. (2)
(dEcelldT)p is known as temperature coefficient of the emf of the cell.
At 300K, ΔH for the reaction Zn+2AgCl→ZnCl2+2Agis−218 kJ/mole while emf of the cell was 1.015V.(dEdT)p of the cell is