At 298 K, the standard electrode potentials of Cu²⁺/Cu, Zn²⁺/Zn, Fe²⁺/Fe and… | Electrochemical Series and Feasibility of Reactions

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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 $2CuSO_4(aq)+2Ag(s)\rightarrow2Cu(s)+Ag_2SO_4(aq)$

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 $FeSO_4(aq)+Zn(s)\rightarrow ZnSO_4(aq)+Fe(s)$

The answer is A.

Solution

Standard reduction potentials: $E^\circ_{Zn^{2+}/Zn} < E^\circ_{Fe^{2+}/Fe} < E^\circ_{Cu^{2+}/Cu} Fe > Cu > Ag A more reactive metal (lower SRP) can displace a less reactive metal from its salt solution. $2CuSO_4(aq) + 2Ag(s) \rightarrow 2Cu(s) + Ag_2SO_4(aq)$ is not possible, as Ag is less reactive than Cu.

Concept spontaneity from electrode potentials

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?

Solution

Redox Reactions in past papers

Practice

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