Question

C)/-1.78 V )-0.89 V Given that the is the standard E) None of these. 24,Forthe reaction N产(aq) + 2Fe2+(aq) → Ni(s) A) 0.80 V 2Fe3 (aq), the standard cell potential cell is oneduo -0.30 v B 0.30 V 9.チ A) +2.81 V +0.52 V D-1.02 V. D) -0.80 V E) 0.43 V 29. Which one E) -2.81 V. spontaneous 25. Consider an electrochemical cell based on the C? following cell diagram:

Answer 1

Q.24

Solution

Correct answer is D = -1.02 V

It is cell reaction consists of anode and cathode.

At anode, oxidationreaction takes place and at cathode reductionreaction takes place.

In this reaction,

1. Nickel get reduce Ni²⁺ + 2e-   _{$\rightarrow$} Ni and its Standard reduction potential is -0.25 V.

2. Iron get oxidises Fe²⁺ _{$\rightarrow$} Fe³⁺+ e- and its Standard reduction potential is 0.77 V

Therefore

E^o = E^o_Cathode - E^o_anode or E^o_reduction - E^o_aoxidation

E^o = -0.25 - 0.77 = -1.02 V

This reaction does not feasible due to answer is -1.02 V, negetive.

In electrochemical series, nickel places up and Iron Fe³⁺/Fe²⁺ places down, therefore when we make electrochemical cell, Nickel should act as anode(oxidation) and Iron should act as cathode (reduction).