Electrochemistry - Result Question 40
####42. Consider the following relations for emf of a electrochemical cell:
[2010]
(i) $\quad$ emf of cell $=($ Oxidation potential of anode $)$ - (Reduction potential of cathode)
(ii) $\quad$ 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 relations are correct?
(a) (ii) and (iv)
(b) (iii) and (i)
(c) (i) and (ii)
(d) (iii) and (iv)
Show Answer
Solution:
(a) $E _{\text{cell }}=E _{\text{cathode }}-E _{\text{anode }}$
$\Rightarrow \quad E _{\text{cell }}=E _{\text{red } / \text{ cathode }}+E _{\text{oxi/anode }}$
$\Rightarrow \quad E _{\text{cell }}=-E _{\text{oxi } / \text{ cathode }}+E _{\text{oxi/anode }}$
Hence, option (a) is correct.
