On the basis of standard electrode potential values, suggest which of the following reactions would take place? (Consult the book for E^{\Theta } value).

(i) Cu + Zn^{2+}\rightarrow Cu^{2+} + Zn
(ii) Mg + Fe^{2+}\rightarrow Mg^{2+} + Fe
(iii) Br_{2} + 2Cl^{-}\rightarrow Cl_{2} + 2Br^{-}
(iv) Fe + Cd^{2+}\rightarrow Cd + Fe^{2+}

Answers (1)

If a reaction might take place or not is dependent on the net cell EMF of the cell. The equation for the same is

E^{^{\circ}}_{cell}=E^{^{\circ}}_{cathode}-E^{^{\circ}}_{anode}

In option (ii) it is clearly visible that, the reaction can take place as Mg has a more negative value of E^{^{\circ}}_{cell}. Hence, Mg is oxidised by losing electron and iron is reduced by gaining an electron.

Mg + Fe^{2+}\rightarrow Mg^{2+} + Fe
 

We can say that Fe undergoes reduction and Mg undergoes oxidation,

 

E^{^{\circ}}_{cathode}=-0.44V

 

E^{^{\circ}}_{anode}=-2.36V


 

E^{^{\circ}}_{cell}=-0.44- \left (-2.36 \right )V

 

E^{^{\circ}}_{cell}=+1.92V

Most Viewed Questions

Preparation Products

Knockout NEET 2024

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 40000/-
Buy Now
Knockout NEET 2025

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 45000/-
Buy Now
NEET Foundation + Knockout NEET 2024

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 54999/- ₹ 42499/-
Buy Now
NEET Foundation + Knockout NEET 2024 (Easy Installment)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 3999/-
Buy Now
NEET Foundation + Knockout NEET 2025 (Easy Installment)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 3999/-
Buy Now
Boost your Preparation for JEE Main with our Foundation Course
 
Exams
Articles
Questions