Q. At 298 K, the standard electrode potentials of $Cu^{2+}/Cu$, $Zn^{2+}/Zn$, $Fe^{2+}/Fe$ and $Ag^+/Ag$ are 0.34 V, -0.76 V, -0.44 V and 0.80 V, respectively. On the basis of standard electrode potential, predict which of the following reaction can not occur?
A) $2CuSO_4(aq) + 2Ag(s) \rightarrow 2Cu(s) + Ag_2SO_4(aq)$
B) $CuSO_4(aq) + Zn(s) \rightarrow ZnSO_4(aq) + Cu(s)$
C) $CuSO_4(aq) + Fe(s) \rightarrow FeSO_4(aq) + Cu(s)$
D) $FeSO_4(aq) + Zn(s) \rightarrow ZnSO_4(aq) + Fe(s)$
Explanation
[Solution] Ag (0.80 V) has a higher reduction potential than Cu (0.34 V), so Ag cannot reduce $Cu^{2+}$; $E^\circ_{cell} = 0.34 - 0.80 < 0$. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.