Q.

The equilibrium constant for the reaction

Zn(s)+Sn2+(aq)Zn2+(aq)+Sn(s) is 1×1020 at 298 K. The magnitude of standard electrode potential of 

Sn/Sn2+ if EZn2+/Znθ=-0.76 V is ______×10-2V. (Nearest integer)

Given:  2.303 RTF=0.059 V                           [2023]


Ans.

(17)

E°=0.0592logKeq

      =0.0592log1020=0.0592×20=0.59 V

Ecell=ESn2+/Sn-EZn2+/Zn

0.59=ESn2+/Sn-(-0.76)

ESn2+/Sn=-0.76+0.59=-0.17

ESn2+/Sn=-0.76+0.59=17×10-2=17