Chemistry - Electrochemistry Question with Solution | TestHub

Question Explanation: Redox feasibility depends on electrode potentials.

Concept: Electrode potential & discharge preference.

Solution:

(1) Cu cannot reduce ${\mathrm{Fe}}^{2+}$ because Cu has a less negative reduction potential and is less reactive than Fe . Hence, ${\mathrm{Fe}}^{2+}\to \mathrm{Fe}$ is not favoured by Cu metal.

(2) Na cannot be obtained by electrolysis of aqueous NaCl because water is reduced instead of ${\mathrm{Na}}^{+}({\mathrm{Na}}^{+}$ has highly negative reduction potential). So sodium metal never deposits in aqueous medium.

(3) Current-carrying ions are not always discharged because discharge depends on electrode potentials, not on which ion carries the current.

(4) Cations having more negative oxidation potential are reduced in preference to water.