The D And F Block Elements Ques 4
4. Four successive members of the first series of the transition metals are listed below. For which one of them the standard potential $(E _{M^{2+} / M}^{\circ})$ value has a positive sign?
[2012 M]
(a) $Co(Z=27)$
(b) $Ni(Z=28)$
(c) $Cu(Z=29)$
(d) $Fe(Z=26)$
Show Answer
Solution:
(c) $E _{Cu^{+2} / Cu}^{\circ}=0.34$ volt,
Other has - ve $E _{\text{R.P. }}^{\circ}$
$E _{Co^{++} / Co}^{\circ}=-0.28$
$E _{Ni^{++} / Ni}^{\circ}=-0.25$
$E _{Fe^{+} / Fe}^{\circ}=-0.44$
BETA
