QJEEM21Ch6a57: JEE Main 2021 Chemistry - Class 12 JEEM21Ch6a57 Solution: The electrode potential of M 2+ /M of 3d-series elements shows…

In the electrode potential series, only copper have positive value for electrode potential because copper has lower tendency than hydrogen to form ions. So, if standard hydrogen electrode (E_Cell = 0) is connected to copper half-cell, the copper with be relatively less negative or less number of electrons.

$E_{(C{u^{2 + }}/Cu)}^o$ = + 0.34 V; $E_{(F{e^{2 + }}/Fe)}^o$ = $-$ 0.41 V

$E_{(C{o^{2 + }}/Co)}^o$ = $-$ 0.28 V; $E_{(Z{n^{2 + }}/Zn)}^o$ = $-$ 0.76 V

$\therefore$ Electrode potential of Cu $E_{(C{u^{2 + }}/Cu)}^o$ show positive value.