Question

Consider the following relations for emf of an electrochemical cell :

(i) EMF of cell = (Oxidation potential of anode) - (Reduction potential of cathode)
(ii) EMF of cell = (Oxidation potential of anode) + (Reduction potential of cathode)
(iii) EMF of cell = (Reduction potential of anode) + (Reduction potential of cathode)
(iv) EMF of cell = (Oxidation potential of anode) - (Oxidation potential of cathode)

Which of the above relation(s) is correct?

• A. (iii) and (i)
• B. (i) and (ii)
• C. (iii) and (iv)
• D. (ii) and (iv)

Answer 1

The correct option is D (ii) and (iv)

The EMF of a cell is given by the following expressions:

EMF of a cell = Reduction potential of cathode - Reduction potential of anode

= Reduction potential of cathode + Oxidation potential of anode

= Oxidation potential of anode - Oxidation potential of cathode

Hence, the relations (ii) and (iv) are correct.

Hence, the correct option is D.