The cell potential `(E_("cell"))` of a reaction is related as `DeltaG = -nFE_("cell")` , where `DeltaG` represents max. useful electrical work .
n=no. of moles of electrons exchanged during the reactino of reversible cell reaction `d(DeltaG) = (DeltaV)dP-(DeltaS).dT`
at constant pressure ` d(DeltaG) = - (DeltaS).dT`
`:'` At constant pressure `DeltaG = DeltaG = DeltaH-TDeltaS`.......(1)
`:. DeltaG = DeltaH + T((d(DeltaG))/(dT))_P` ......... (B)
` ((dE_("cell"))/(dT))_(P)` is known as temperature coefficient of the e.m.f of the cell
When `DeltaS` increases, temperature coefficient of the emf of cell

Options

A. Constant
B. Decreases
C. Suddenly decreases
D. Increases

Answer

D

Explanation

`DeltaG = DeltaH -T. DeltaS , Delta G = DeltaH + T ((d(DeltaG))/(DeltaT))_(P)`
` implies -DeltaS = ((d(DeltaG))/(dT))_P - DeltaS = ((d(-nFE_("cell")^(0)))/(dt))_(P)- DeltaS = -nF((dE_("cell"))/(dt))_(P)`
`((dE_("cell"))/(dt))_P = (DeltaS)/(nF) implies If DeltaS uarr ` then `((dE_("cell"))/(dt))_(P)uarr`