The equilibrium constant for the reaction
$\mathrm{Zn(s)+Sn^{2+}(aq)}$ $\rightleftharpoons$ $\mathrm{Zn^{2+}(aq)+Sn(s)}$ is $1\times10^{20}$ at 298 K. The magnitude of standard electrode potential of $\mathrm{Sn/Sn^{2+}}$ if $\mathrm{E_{Z{n^{2 + }}/Zn}^\Theta = - 0.76~V}$ is __________ $\times 10^{-2}$ V. (Nearest integer)
Given : $\mathrm{\frac{2.303RT}{F}=0.059~V}$
Answer (integer)
17
Solution
<p>$E_{cell}^o = {{2.303\,RT} \over {2F}}\log k$</p>
<p>$E_{cell}^o = {{0.059} \over 2}\log ({10^{20}})$</p>
<p>$E_{Z{n^{2 + }}/Zn}^o + 0.76 = 0.59$</p>
<p>$E_{Z{n^{2 + }}/Zn}^o = 0.59 - 0.76$</p>
<p>$E_{Zn/Z{n^{2 + }}}^o = 0.17\,V$</p>
About this question
Subject: Chemistry · Chapter: Electrochemistry · Topic: Electrochemical Cells
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