JEE Advanced Model Paper 8 with solutions for online practice

Electrical energy produced by a reversible electrochemical cell is given by the free energy decrease (-ΔG) of the reaction occurring in the cell. According to Gibbs- Helmholtz equation, decrease in freeenergy is given by -ΔG = -ΔH - T [

δ(ΔG)

δT

]p where -ΔH is the decrease in enthalpy of the cell reaction at constant pressure. EMF of the cell, E =

−ΔH

nF

+ T [

δE

δT

]p . By measuring the emf of the cell and its temperature co-efficient,thermodynamic quantities like ΔH, ΔG and ΔS can be determined. Standard emf of the cell is related to equilibrium constant of the cell reaction as E° =

2.303RTlogk

nF